Update to 1.20.5

- Force encoding to UTF-8
 - Fix npm not being found on the path
 - Test building common/web on OSX and Windows

.github/workflows/main-ci.yml

@@ -14,7 +14,7 @@ jobs:
     - name: 📥 Set up Java
       uses: actions/setup-java@v4
       with:
-        java-version: 17
+        java-version: 21
         distribution: 'temurin'
 
     - name: 📥 Setup Gradle
@@ -58,13 +58,13 @@ jobs:
         find projects/forge/build/libs projects/fabric/build/libs -type f -regex '.*[0-9.]+\(-SNAPSHOT\)?\.jar$' -exec bash -c 'cp {} "jars/$(basename {} .jar)-$(git rev-parse HEAD).jar"' \;
 
     - name: 📤 Upload Jar
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: CC-Tweaked
         path: ./jars
 
     - name: 📤 Upload coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
 
   build-core:
     strategy:
@@ -81,24 +81,28 @@ jobs:
     runs-on: ${{ matrix.uses }}
 
     steps:
-    - name: Clone repository
+    - name: 📥 Clone repository
       uses: actions/checkout@v4
 
-    - name: Set up Java
+    - name: 📥 Set up Java
       uses: actions/setup-java@v4
       with:
-        java-version: 17
+        java-version: 21
         distribution: 'temurin'
 
-    - name: Setup Gradle
+    - name: 📥 Setup Gradle
       uses: gradle/actions/setup-gradle@v3
       with:
         cache-read-only: ${{ !startsWith(github.ref, 'refs/heads/mc-') }}
 
-    - name: Run tests
+    - name: ⚒️ Build
+      run: |
+        ./gradlew --configure-on-demand :core:assemble :web:assemble
+
+    - name: 🧪 Run tests
       run: |
         ./gradlew --configure-on-demand :core:test
 
-    - name: Parse test reports
+    - name: 🧪 Parse test reports
       run: python3 ./tools/parse-reports.py
       if: ${{ failure() }}

.github/workflows/make-doc.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Set up Java
       uses: actions/setup-java@v4
       with:
-        java-version: 17
+        java-version: 21
         distribution: 'temurin'
 
     - name: Setup Gradle

.gitpod.yml

@@ -1,26 +0,0 @@
-# SPDX-FileCopyrightText: 2021 The CC: Tweaked Developers
-#
-# SPDX-License-Identifier: MPL-2.0
-
-image:
-  file: config/gitpod/Dockerfile
-
-ports:
-  - port: 25565
-    onOpen: notify
-
-vscode:
-  extensions:
-    - eamodio.gitlens
-    - github.vscode-pull-request-github
-    - ms-azuretools.vscode-docker
-    - redhat.java
-    - richardwillis.vscode-gradle
-    - vscjava.vscode-java-debug
-    - vscode.github
-
-tasks:
-  - name: Setup pre-commit hool
-    init: pre-commit install --allow-missing-config
-  - name: Install npm packages
-    init: npm ci

CONTRIBUTING.md

@@ -29,9 +29,9 @@ ## Setting up a development environment
 In order to develop CC: Tweaked, you'll need to download the source code and then run it.
 
  - Make sure you've got the following software installed:
-   - Java Development Kit (JDK) installed. This can be downloaded from [Adoptium].
+   - Java Development Kit (JDK). This can be downloaded from [Adoptium].
    - [Git](https://git-scm.com/).
-   - If you want to work on documentation, [NodeJS][node].
+   - [NodeJS][node].
 
  - Download CC: Tweaked's source code:
    ```

build.gradle.kts

@@ -5,9 +5,8 @@
 import cc.tweaked.gradle.JUnitExt
 import net.fabricmc.loom.api.LoomGradleExtensionAPI
 import net.fabricmc.loom.util.gradle.SourceSetHelper
-import org.jetbrains.gradle.ext.compiler
-import org.jetbrains.gradle.ext.runConfigurations
-import org.jetbrains.gradle.ext.settings
+import org.jetbrains.gradle.ext.*
+import org.jetbrains.gradle.ext.Application
 
 plugins {
     publishing
@@ -86,6 +85,19 @@ idea.project.settings.runConfigurations {
         moduleName = "${idea.project.name}.forge.test"
         packageName = ""
     }
+
+    register<Application>("Standalone") {
+        moduleName = "${idea.project.name}.standalone.main"
+        mainClass = "cc.tweaked.standalone.Main"
+        programParameters = "--resources=projects/core/src/main/resources --term=80x30 --allow-local-domains"
+    }
+}
+
+// Build with the IntelliJ, rather than through Gradle. This may require setting the "Compiler Output" option in
+// "Project Structure".
+idea.project.settings.delegateActions {
+    delegateBuildRunToGradle = false
+    testRunner = ActionDelegationConfig.TestRunner.PLATFORM
 }
 
 idea.project.settings.compiler.javac {

buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts

@@ -78,8 +78,16 @@ dependencies {
 // Configure default JavaCompile tasks with our arguments.
 sourceSets.all {
     tasks.named(compileJavaTaskName, JavaCompile::class.java) {
-        // Processing just gives us "No processor claimed any of these annotations", so skip that!
-        options.compilerArgs.addAll(listOf("-Xlint", "-Xlint:-processing"))
+
+        options.compilerArgs.addAll(
+            listOf(
+                "-Xlint",
+                // Processing just gives us "No processor claimed any of these annotations", so skip that!
+                "-Xlint:-processing",
+                // We violate this pattern too often for it to be a helpful warning. Something to improve one day!
+                "-Xlint:-this-escape",
+            ),
+        )
 
         options.errorprone {
             check("InvalidBlockTag", CheckSeverity.OFF) // Broken by @cc.xyz
@@ -148,7 +156,7 @@ tasks.javadoc {
     options {
         val stdOptions = this as StandardJavadocDocletOptions
         stdOptions.addBooleanOption("Xdoclint:all,-missing", true)
-        stdOptions.links("https://docs.oracle.com/en/java/javase/17/docs/api/")
+        stdOptions.links("https://docs.oracle.com/en/java/javase/21/docs/api/")
     }
 }
 

buildSrc/src/main/kotlin/cc/tweaked/gradle/CCTweakedExtension.kt

@@ -35,7 +35,6 @@
 import java.io.File
 import java.io.IOException
 import java.net.URI
-import java.net.URL
 import java.util.regex.Pattern
 
 abstract class CCTweakedExtension(
@@ -226,12 +225,12 @@ fun <T> jacoco(task: NamedDomainObjectProvider<T>) where T : Task, T : JavaForkO
      * where possible.
      */
     fun downloadFile(label: String, url: String): File {
-        val url = URL(url)
+        val url = URI(url)
         val path = File(url.path)
 
         project.repositories.ivy {
             name = label
-            setUrl(URI(url.protocol, url.userInfo, url.host, url.port, path.parent, null, null))
+            setUrl(URI(url.scheme, url.userInfo, url.host, url.port, path.parent, null, null))
             patternLayout {
                 artifact("[artifact].[ext]")
             }

buildSrc/src/main/kotlin/cc/tweaked/gradle/CCTweakedPlugin.kt

@@ -42,6 +42,6 @@ private fun extendIdea(project: Project) {
     }
 
     companion object {
-        val JAVA_VERSION = JavaLanguageVersion.of(17)
+        val JAVA_VERSION = JavaLanguageVersion.of(21)
     }
 }

buildSrc/src/main/kotlin/cc/tweaked/gradle/Node.kt

@@ -46,7 +46,7 @@ abstract class NpmInstall : DefaultTask() {
     @TaskAction
     fun install() {
         project.exec {
-            commandLine("npm", "ci")
+            commandLine(ProcessHelpers.getExecutable("npm"), "ci")
             workingDir = projectRoot.get().asFile
         }
     }
@@ -59,6 +59,6 @@ fun install() {
 abstract class NpxExecToDir : ExecToDir() {
     init {
         dependsOn(NpmInstall.TASK_NAME)
-        executable = "npx"
+        executable = ProcessHelpers.getExecutable("npx")
     }
 }

buildSrc/src/main/kotlin/cc/tweaked/gradle/ProcessHelpers.kt

@@ -9,6 +9,7 @@
 import java.io.BufferedReader
 import java.io.File
 import java.io.InputStreamReader
+import java.nio.charset.StandardCharsets
 
 internal object ProcessHelpers {
     fun startProcess(vararg command: String): Process {
@@ -34,7 +35,7 @@ fun captureLines(vararg command: String): List<String> {
         val process = startProcess(*command)
         process.outputStream.close()
 
-        val out = BufferedReader(InputStreamReader(process.inputStream)).use { reader ->
+        val out = BufferedReader(InputStreamReader(process.inputStream, StandardCharsets.UTF_8)).use { reader ->
             reader.lines().filter { it.isNotEmpty() }.toList()
         }
         ProcessGroovyMethods.closeStreams(process)
@@ -46,6 +47,28 @@ fun onPath(name: String): Boolean {
         val path = System.getenv("PATH") ?: return false
         return path.splitToSequence(File.pathSeparator).any { File(it, name).exists() }
     }
+
+    /**
+     * Search for an executable on the `PATH` if required.
+     *
+     * [Process]/[ProcessBuilder] does not handle all executable file extensions on Windows (such as `.com). When on
+     * Windows, this function searches `PATH` and `PATHEXT` for an executable matching [name].
+     */
+    fun getExecutable(name: String): String {
+        if (!System.getProperty("os.name").lowercase().contains("windows")) return name
+
+        val path = (System.getenv("PATH") ?: return name).split(File.pathSeparator)
+        val pathExt = (System.getenv("PATHEXT") ?: return name).split(File.pathSeparator)
+
+        for (pathEntry in path) {
+            for (ext in pathExt) {
+                val resolved = File(pathEntry, name + ext)
+                if (resolved.exists()) return resolved.getAbsolutePath()
+            }
+        }
+
+        return name
+    }
 }
 
 internal fun Process.waitForOrThrow(message: String) {

config/checkstyle/suppressions.xml

@@ -22,4 +22,7 @@ SPDX-License-Identifier: MPL-2.0
 
     <!-- Allow underscores in our test classes. -->
     <suppress checks="MethodName" files=".*(Contract|Test).java" />
+
+    <!-- Allow underscores in Mixin classes -->
+    <suppress checks="TypeName" files=".*[\\/]mixin[\\/].*.java" />
 </suppressions>

config/gitpod/Dockerfile

@@ -1,12 +0,0 @@
-# SPDX-FileCopyrightText: 2021 The CC: Tweaked Developers
-#
-# SPDX-License-Identifier: MPL-2.0
-
-FROM gitpod/workspace-base
-
-USER gitpod
-
-RUN sudo apt-get -q update \
- && sudo apt-get install -yq openjdk-16-jdk python3-pip npm \
- && sudo pip3 install pre-commit \
- && sudo update-java-alternatives --set java-1.16.0-openjdk-amd64

doc/guides/speaker_audio.md

@@ -131,7 +131,7 @@ ## Storing audio
 First, we require the dfpwm module and call [`cc.audio.dfpwm.make_decoder`] to construct a new decoder. This decoder
 accepts blocks of DFPWM data and converts it to a list of 8-bit amplitudes, which we can then play with our speaker.
 
-As mentioned above, [`speaker.playAudio`] accepts at most 128×1024 samples in one go. DFPMW uses a single bit for each
+As mentioned above, [`speaker.playAudio`] accepts at most 128×1024 samples in one go. DFPWM uses a single bit for each
 sample, which means we want to process our audio in chunks of 16×1024 bytes (16KiB). In order to do this, we use
 [`io.lines`], which provides a nice way to loop over chunks of a file. You can of course just use [`fs.open`] and
 [`fs.ReadHandle.read`] if you prefer.

gradle.properties

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: MPL-2.0
 
-org.gradle.jvmargs=-Xmx3G
+org.gradle.jvmargs=-Xmx3G -Dfile.encoding=UTF-8
 org.gradle.parallel=true
 
 kotlin.stdlib.default.dependency=false
@@ -13,4 +13,4 @@ isUnstable=true
 modVersion=1.110.2
 
 # Minecraft properties: We want to configure this here so we can read it in settings.gradle
-mcVersion=1.20.4
+mcVersion=1.20.5

gradle/libs.versions.toml

@@ -7,26 +7,26 @@
 # Minecraft
 # MC version is specified in gradle.properties, as we need that in settings.gradle.
 # Remember to update corresponding versions in fabric.mod.json/mods.toml
-fabric-api = "0.93.1+1.20.4"
-fabric-loader = "0.15.3"
-neoForge = "20.4.210"
+fabric-api = "0.97.6+1.20.5"
+fabric-loader = "0.15.10"
+neoForge = "20.5.0-beta"
 neoForgeSpi = "8.0.1"
 mixin = "0.8.5"
-parchment = "2023.12.31"
-parchmentMc = "1.20.3"
-yarn = "1.20.4+build.3"
+parchment = "2024.04.14"
+parchmentMc = "1.20.4"
+yarn = "1.20.5+build.1"
 
 # Core dependencies (these versions are tied to the version Minecraft uses)
 fastutil = "8.5.12"
 guava = "32.1.2-jre"
 netty = "4.1.97.Final"
-slf4j = "2.0.7"
+slf4j = "2.0.9"
 
 # Core dependencies (independent of Minecraft)
 asm = "9.6"
 autoService = "1.1.1"
 checkerFramework = "3.42.0"
-cobalt = "0.9.2"
+cobalt = { strictly = "0.9.3" }
 commonsCli = "1.6.0"
 jetbrainsAnnotations = "24.1.0"
 jsr305 = "3.0.2"
@@ -46,6 +46,7 @@ oculus = "1.2.5"
 rei = "14.0.688"
 rubidium = "0.6.1"
 sodium = "mc1.20-0.4.10"
+mixinExtra = "0.3.5"
 
 # Testing
 hamcrest = "2.2"
@@ -59,19 +60,19 @@ checkstyle = "10.14.1"
 curseForgeGradle = "1.1.18"
 errorProne-core = "2.23.0"
 errorProne-plugin = "3.1.0"
-fabric-loom = "1.5.7"
+fabric-loom = "1.6.7"
 githubRelease = "2.5.2"
 gradleVersions = "0.50.0"
 ideaExt = "1.1.7"
 illuaminate = "0.1.0-71-g378d86e"
 lwjgl = "3.3.3"
 minotaur = "2.8.7"
-neoGradle = "7.0.100"
+neoGradle = "7.0.107"
 nullAway = "0.10.25"
 spotless = "6.23.3"
 taskTree = "2.1.1"
-teavm = "0.10.0-SQUID.3"
-vanillaExtract = "0.1.2"
+teavm = "0.10.0-SQUID.4"
+vanillaExtract = "0.1.3"
 versionCatalogUpdate = "0.8.1"
 
 [libraries]
@@ -109,6 +110,7 @@ jei-api = { module = "mezz.jei:jei-1.20.4-common-api", version.ref = "jei" }
 jei-fabric = { module = "mezz.jei:jei-1.20.4-fabric", version.ref = "jei" }
 jei-forge = { module = "mezz.jei:jei-1.20.4-forge", version.ref = "jei" }
 mixin = { module = "org.spongepowered:mixin", version.ref = "mixin" }
+mixinExtra = { module = "io.github.llamalad7:mixinextras-common", version.ref = "mixinExtra" }
 modmenu = { module = "com.terraformersmc:modmenu", version.ref = "modmenu" }
 moreRed = { module = "commoble.morered:morered-1.20.1", version.ref = "moreRed" }
 oculus = { module = "maven.modrinth:oculus", version.ref = "oculus" }
@@ -152,6 +154,7 @@ neoGradle-userdev = { module = "net.neoforged.gradle:userdev", version.ref = "ne
 nullAway = { module = "com.uber.nullaway:nullaway", version.ref = "nullAway" }
 spotless = { module = "com.diffplug.spotless:spotless-plugin-gradle", version.ref = "spotless" }
 teavm-classlib = { module = "org.teavm:teavm-classlib", version.ref = "teavm" }
+teavm-core = { module = "org.teavm:teavm-core", version.ref = "teavm" }
 teavm-jso = { module = "org.teavm:teavm-jso", version.ref = "teavm" }
 teavm-jso-apis = { module = "org.teavm:teavm-jso-apis", version.ref = "teavm" }
 teavm-jso-impl = { module = "org.teavm:teavm-jso-impl", version.ref = "teavm" }
@@ -178,7 +181,7 @@ externalMods-common = ["jei-api", "nightConfig-core", "nightConfig-toml"]
 externalMods-forge-compile = ["moreRed", "oculus", "jei-api"]
 externalMods-forge-runtime = []
 externalMods-fabric-compile = ["fabricPermissions", "iris", "jei-api", "rei-api", "rei-builtin"]
-externalMods-fabric-runtime = ["jei-fabric", "modmenu"]
+externalMods-fabric-runtime = [] # ["jei-fabric", "modmenu"]
 
 # Testing
 test = ["junit-jupiter-api", "junit-jupiter-params", "hamcrest", "jqwik-api"]

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModeller.java

@@ -9,7 +9,7 @@
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import net.minecraft.client.resources.model.UnbakedModel;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.resources.ResourceLocation;
 
 import javax.annotation.Nullable;
@@ -38,7 +38,7 @@ public interface TurtleUpgradeModeller<T extends ITurtleUpgrade> {
      * @param data    Upgrade data instance for current turtle side.
      * @return The model that you wish to be used to render your upgrade.
      */
-    TransformedModel getModel(T upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, CompoundTag data);
+    TransformedModel getModel(T upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, DataComponentPatch data);
 
     /**
      * Get a list of models that this turtle modeller depends on.
@@ -55,7 +55,7 @@ default Collection<ResourceLocation> getDependencies() {
     }
 
     /**
-     * A basic {@link TurtleUpgradeModeller} which renders using the upgrade's {@linkplain ITurtleUpgrade#getUpgradeItem(CompoundTag)}
+     * A basic {@link TurtleUpgradeModeller} which renders using the upgrade's {@linkplain ITurtleUpgrade#getUpgradeItem(DataComponentPatch)}
      * upgrade item}.
      * <p>
      * This uses appropriate transformations for "flat" items, namely those extending the {@literal minecraft:item/generated}
@@ -80,7 +80,7 @@ static <T extends ITurtleUpgrade> TurtleUpgradeModeller<T> flatItem() {
     static <T extends ITurtleUpgrade> TurtleUpgradeModeller<T> sided(ResourceLocation left, ResourceLocation right) {
         return new TurtleUpgradeModeller<>() {
             @Override
-            public TransformedModel getModel(T upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, CompoundTag data) {
+            public TransformedModel getModel(T upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, DataComponentPatch data) {
                 return TransformedModel.of(side == TurtleSide.LEFT ? left : right);
             }
 

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModellers.java

@@ -11,7 +11,7 @@
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.impl.client.ClientPlatformHelper;
 import net.minecraft.client.Minecraft;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import org.joml.Matrix4f;
 
 import javax.annotation.Nullable;
@@ -36,7 +36,7 @@ private static Transformation getMatrixFor(float offset) {
 
     private static final class UpgradeItemModeller implements TurtleUpgradeModeller<ITurtleUpgrade> {
         @Override
-        public TransformedModel getModel(ITurtleUpgrade upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, CompoundTag data) {
+        public TransformedModel getModel(ITurtleUpgrade upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, DataComponentPatch data) {
             var stack = upgrade.getUpgradeItem(data);
             var model = Minecraft.getInstance().getItemRenderer().getItemModelShaper().getItemModel(stack);
             if (stack.hasFoil()) model = ClientPlatformHelper.get().createdFoiledModel(model);

projects/common-api/src/main/java/dan200/computercraft/api/ComputerCraftTags.java

@@ -6,10 +6,12 @@
 
 import net.minecraft.core.registries.Registries;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.tags.ItemTags;
 import net.minecraft.tags.TagKey;
 import net.minecraft.world.InteractionHand;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.context.UseOnContext;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.Block;
@@ -35,6 +37,14 @@ public static class Items {
          */
         public static final TagKey<Item> TURTLE_CAN_PLACE = make("turtle_can_place");
 
+        /**
+         * Items which can be dyed.
+         * <p>
+         * This is similar to {@link ItemTags#DYEABLE}, but allows cleaning the item with a sponge, rather than in a
+         * cauldron.
+         */
+        public static final TagKey<Item> DYEABLE = make("dyeable");
+
         private static TagKey<Item> make(String name) {
             return TagKey.create(Registries.ITEM, new ResourceLocation(ComputerCraftAPI.MOD_ID, name));
         }
@@ -75,8 +85,8 @@ public static class Blocks {
         public static final TagKey<Block> TURTLE_HOE_BREAKABLE = make("turtle_hoe_harvestable");
 
         /**
-         * Block which can be {@linkplain BlockState#use(Level, Player, InteractionHand, BlockHitResult) used} when
-         * calling {@code turtle.place()}.
+         * Block which can be {@linkplain BlockState#useItemOn(ItemStack, Level, Player, InteractionHand, BlockHitResult) used}
+         * when calling {@code turtle.place()}.
          */
         public static final TagKey<Block> TURTLE_CAN_USE = make("turtle_can_use");
 

projects/common-api/src/main/java/dan200/computercraft/api/pocket/IPocketAccess.java

@@ -5,7 +5,7 @@
 package dan200.computercraft.api.pocket;
 
 import dan200.computercraft.api.upgrades.UpgradeBase;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.item.ItemStack;
 
@@ -67,18 +67,19 @@ public interface IPocketAccess {
      * This is persisted between computer reboots and chunk loads.
      *
      * @return The upgrade's NBT.
-     * @see #updateUpgradeNBTData()
-     * @see UpgradeBase#getUpgradeItem(CompoundTag)
+     * @see #setUpgradeData(DataComponentPatch)
+     * @see UpgradeBase#getUpgradeItem(DataComponentPatch)
      * @see UpgradeBase#getUpgradeData(ItemStack)
      */
-    CompoundTag getUpgradeNBTData();
+    DataComponentPatch getUpgradeData();
 
     /**
-     * Mark the upgrade-specific NBT as dirty.
+     * Update the upgrade-specific data.
      *
-     * @see #getUpgradeNBTData()
+     * @param data The new upgrade data.
+     * @see #getUpgradeData()
      */
-    void updateUpgradeNBTData();
+    void setUpgradeData(DataComponentPatch data);
 
     /**
      * Remove the current peripheral and create a new one.

projects/common-api/src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -12,7 +12,7 @@
 import dan200.computercraft.api.upgrades.UpgradeData;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.world.Container;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
@@ -229,37 +229,22 @@ public interface ITurtleAccess {
      * @param side The side to get the upgrade from.
      * @return The upgrade on the specified side of the turtle, if there is one.
      * @see #getUpgradeWithData(TurtleSide)
-     * @see #setUpgradeWithData(TurtleSide, UpgradeData)
+     * @see #setUpgrade(TurtleSide, UpgradeData)
      */
     @Nullable
     ITurtleUpgrade getUpgrade(TurtleSide side);
 
     /**
-     * Returns the upgrade on the specified side of the turtle, along with its {@linkplain #getUpgradeNBTData(TurtleSide)
+     * Returns the upgrade on the specified side of the turtle, along with its {@linkplain #getUpgradeData(TurtleSide)
      * update data}.
      *
      * @param side The side to get the upgrade from.
      * @return The upgrade on the specified side of the turtle, along with its upgrade data, if there is one.
      * @see #getUpgradeWithData(TurtleSide)
-     * @see #setUpgradeWithData(TurtleSide, UpgradeData)
+     * @see #setUpgrade(TurtleSide, UpgradeData)
      */
-    default @Nullable UpgradeData<ITurtleUpgrade> getUpgradeWithData(TurtleSide side) {
-        var upgrade = getUpgrade(side);
-        return upgrade == null ? null : UpgradeData.of(upgrade, getUpgradeNBTData(side));
-    }
-
-    /**
-     * Set the upgrade for a given side, resetting peripherals and clearing upgrade specific data.
-     *
-     * @param side    The side to set the upgrade on.
-     * @param upgrade The upgrade to set, may be {@code null} to clear.
-     * @see #getUpgrade(TurtleSide)
-     * @deprecated Use {@link #setUpgradeWithData(TurtleSide, UpgradeData)}
-     */
-    @Deprecated
-    default void setUpgrade(TurtleSide side, @Nullable ITurtleUpgrade upgrade) {
-        setUpgradeWithData(side, upgrade == null ? null : UpgradeData.ofDefault(upgrade));
-    }
+    @Nullable
+    UpgradeData<ITurtleUpgrade> getUpgradeWithData(TurtleSide side);
 
     /**
      * Set the upgrade for a given side and its upgrade data.
@@ -268,7 +253,7 @@ default void setUpgrade(TurtleSide side, @Nullable ITurtleUpgrade upgrade) {
      * @param upgrade The upgrade to set, may be {@code null} to clear.
      * @see #getUpgradeWithData(TurtleSide)
      */
-    void setUpgradeWithData(TurtleSide side, @Nullable UpgradeData<ITurtleUpgrade> upgrade);
+    void setUpgrade(TurtleSide side, @Nullable UpgradeData<ITurtleUpgrade> upgrade);
 
     /**
      * Returns the peripheral created by the upgrade on the specified side of the turtle, if there is one.
@@ -282,23 +267,23 @@ default void setUpgrade(TurtleSide side, @Nullable ITurtleUpgrade upgrade) {
     /**
      * Get an upgrade-specific NBT compound, which can be used to store arbitrary data.
      * <p>
-     * This will be persisted across turtle restarts and chunk loads, as well as being synced to the client. You must
-     * call {@link #updateUpgradeNBTData(TurtleSide)} after modifying it.
+     * This will be persisted across turtle restarts and chunk loads, as well as being synced to the client. You can
+     * call {@link #setUpgrade(TurtleSide, UpgradeData)} to modify it.
      *
      * @param side The side to get the upgrade data for.
      * @return The upgrade-specific data.
-     * @see #updateUpgradeNBTData(TurtleSide)
-     * @see UpgradeBase#getUpgradeItem(CompoundTag)
+     * @see #setUpgradeData(TurtleSide, DataComponentPatch)
+     * @see UpgradeBase#getUpgradeItem(DataComponentPatch)
      * @see UpgradeBase#getUpgradeData(ItemStack)
      */
-    CompoundTag getUpgradeNBTData(TurtleSide side);
+    DataComponentPatch getUpgradeData(TurtleSide side);
 
     /**
-     * Mark the upgrade-specific data as dirty on a specific side. This is required for the data to be synced to the
-     * client and persisted.
+     * Update the upgrade-specific data.
      *
-     * @param side The side to mark dirty.
-     * @see #updateUpgradeNBTData(TurtleSide)
+     * @param side The side to set the upgrade data for.
+     * @param data The new upgrade data.
+     * @see #getUpgradeData(TurtleSide)
      */
-    void updateUpgradeNBTData(TurtleSide side);
+    void setUpgradeData(TurtleSide side, DataComponentPatch data);
 }

projects/common-api/src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -10,7 +10,7 @@
 import dan200.computercraft.impl.ComputerCraftAPIService;
 import net.minecraft.core.Direction;
 import net.minecraft.core.Registry;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.resources.ResourceKey;
 
 import javax.annotation.Nullable;
@@ -133,7 +133,7 @@ default void update(ITurtleAccess turtle, TurtleSide side) {
      * @param upgradeData Data that currently stored for this upgrade
      * @return Filtered version of this data.
      */
-    default CompoundTag getPersistedData(CompoundTag upgradeData) {
+    default DataComponentPatch getPersistedData(DataComponentPatch upgradeData) {
         return upgradeData;
     }
 }

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleToolDurability.java

@@ -4,8 +4,8 @@
 
 package dan200.computercraft.api.turtle;
 
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.util.StringRepresentable;
-import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.item.ItemStack;
 
 /**
@@ -21,7 +21,7 @@ public enum TurtleToolDurability implements StringRepresentable {
 
     /**
      * The equipped tool consumes durability if it is {@linkplain ItemStack#isEnchanted() enchanted} or has
-     * {@linkplain ItemStack#getAttributeModifiers(EquipmentSlot) custom attribute modifiers}.
+     * {@linkplain DataComponents#ATTRIBUTE_MODIFIERS custom attribute modifiers}.
      */
     WHEN_ENCHANTED("when_enchanted"),
 

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeDataProvider.java

@@ -9,12 +9,12 @@
 import dan200.computercraft.api.upgrades.UpgradeDataProvider;
 import dan200.computercraft.api.upgrades.UpgradeSerialiser;
 import dan200.computercraft.impl.RegistryHelper;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.data.DataGenerator;
 import net.minecraft.data.PackOutput;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.tags.TagKey;
-import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.ai.attributes.Attributes;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
@@ -111,7 +111,7 @@ public ToolBuilder damageMultiplier(float damageMultiplier) {
 
         /**
          * Indicate that this upgrade allows items which have been {@linkplain ItemStack#isEnchanted() enchanted} or have
-         * {@linkplain ItemStack#getAttributeModifiers(EquipmentSlot) custom attribute modifiers}.
+         * {@linkplain DataComponents#ATTRIBUTE_MODIFIERS custom attribute modifiers}.
          *
          * @return The tool builder, for further use.
          */

projects/common-api/src/main/java/dan200/computercraft/api/upgrades/UpgradeBase.java

@@ -10,12 +10,10 @@
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import net.minecraft.Util;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 
-import java.util.Objects;
-
 /**
  * Common functionality between {@link ITurtleUpgrade} and {@link IPocketUpgrade}.
  */
@@ -56,8 +54,8 @@ public interface UpgradeBase {
     /**
      * Returns the item stack representing a currently equipped turtle upgrade.
      * <p>
-     * While upgrades can store upgrade data ({@link ITurtleAccess#getUpgradeNBTData(TurtleSide)} and
-     * {@link IPocketAccess#getUpgradeNBTData()}}, by default this data is discarded when an upgrade is unequipped,
+     * While upgrades can store upgrade data ({@link ITurtleAccess#getUpgradeData(TurtleSide)} and
+     * {@link IPocketAccess#getUpgradeData()}}, by default this data is discarded when an upgrade is unequipped,
      * and the original item stack is returned.
      * <p>
      * By overriding this method, you can create a new {@link ItemStack} which contains enough data to
@@ -69,24 +67,24 @@ public interface UpgradeBase {
      * @param upgradeData The current upgrade data. This should <strong>NOT</strong> be mutated.
      * @return The item stack returned when unequipping.
      */
-    default ItemStack getUpgradeItem(CompoundTag upgradeData) {
+    default ItemStack getUpgradeItem(DataComponentPatch upgradeData) {
         return getCraftingItem();
     }
 
     /**
      * Extract upgrade data from an {@link ItemStack}.
      * <p>
-     * This upgrade data will be available with {@link ITurtleAccess#getUpgradeNBTData(TurtleSide)} or
-     * {@link IPocketAccess#getUpgradeNBTData()}.
+     * This upgrade data will be available with {@link ITurtleAccess#getUpgradeData(TurtleSide)} or
+     * {@link IPocketAccess#getUpgradeData()}.
      * <p>
-     * This should be an inverse to {@link #getUpgradeItem(CompoundTag)}.
+     * This should be an inverse to {@link #getUpgradeItem(DataComponentPatch)}.
      *
      * @param stack The stack that was equipped by the turtle or pocket computer. This will have the same item as
      *              {@link #getCraftingItem()}.
      * @return The upgrade data that should be set on the turtle or pocket computer.
      */
-    default CompoundTag getUpgradeData(ItemStack stack) {
-        return new CompoundTag();
+    default DataComponentPatch getUpgradeData(ItemStack stack) {
+        return DataComponentPatch.EMPTY;
     }
 
     /**
@@ -110,11 +108,9 @@ default boolean isItemSuitable(ItemStack stack) {
 
         // A more expanded form of ItemStack.areShareTagsEqual, but allowing an empty tag to be equal to a
         // null one.
-        var tag = stack.getTag();
-        var craftingTag = crafting.getTag();
-        if (tag == craftingTag) return true;
-        if (tag == null) return Objects.requireNonNull(craftingTag).isEmpty();
-        if (craftingTag == null) return tag.isEmpty();
+        // TODO(1.20.5): Something better than this
+        var tag = stack.getComponents();
+        var craftingTag = crafting.getComponents();
         return tag.equals(craftingTag);
     }
 

projects/common-api/src/main/java/dan200/computercraft/api/upgrades/UpgradeData.java

@@ -6,23 +6,17 @@
 
 import dan200.computercraft.api.pocket.IPocketUpgrade;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.world.item.ItemStack;
-import org.jetbrains.annotations.Contract;
-
-import javax.annotation.Nullable;
 
 /**
  * An upgrade (i.e. a {@link ITurtleUpgrade}) and its current upgrade data.
- * <p>
- * <strong>IMPORTANT:</strong> The {@link #data()} in an upgrade data is often a reference to the original upgrade data.
- * Be careful to take a {@linkplain #copy() defensive copy} if you plan to use the data in this upgrade.
  *
  * @param upgrade The current upgrade.
  * @param data    The upgrade's data.
  * @param <T>     The type of upgrade, either {@link ITurtleUpgrade} or {@link IPocketUpgrade}.
  */
-public record UpgradeData<T extends UpgradeBase>(T upgrade, CompoundTag data) {
+public record UpgradeData<T extends UpgradeBase>(T upgrade, DataComponentPatch data) {
     /**
      * A utility method to construct a new {@link UpgradeData} instance.
      *
@@ -31,7 +25,7 @@ public record UpgradeData<T extends UpgradeBase>(T upgrade, CompoundTag data) {
      * @param <T>     The type of upgrade.
      * @return The new {@link UpgradeData} instance.
      */
-    public static <T extends UpgradeBase> UpgradeData<T> of(T upgrade, CompoundTag data) {
+    public static <T extends UpgradeBase> UpgradeData<T> of(T upgrade, DataComponentPatch data) {
         return new UpgradeData<>(upgrade, data);
     }
 
@@ -47,19 +41,7 @@ public static <T extends UpgradeBase> UpgradeData<T> ofDefault(T upgrade) {
     }
 
     /**
-     * Take a copy of a (possibly {@code null}) {@link UpgradeData} instance.
-     *
-     * @param upgrade The copied upgrade data.
-     * @param <T>     The type of upgrade.
-     * @return The newly created upgrade data.
-     */
-    @Contract("!null -> !null; null -> null")
-    public static <T extends UpgradeBase> @Nullable UpgradeData<T> copyOf(@Nullable UpgradeData<T> upgrade) {
-        return upgrade == null ? null : upgrade.copy();
-    }
-
-    /**
-     * Get the {@linkplain UpgradeBase#getUpgradeItem(CompoundTag) upgrade item} for this upgrade.
+     * Get the {@linkplain UpgradeBase#getUpgradeItem(DataComponentPatch) upgrade item} for this upgrade.
      * <p>
      * This returns a defensive copy of the item, to prevent accidental mutation of the upgrade data or original
      * {@linkplain UpgradeBase#getCraftingItem() upgrade stack}.
@@ -69,14 +51,4 @@ public static <T extends UpgradeBase> UpgradeData<T> ofDefault(T upgrade) {
     public ItemStack getUpgradeItem() {
         return upgrade.getUpgradeItem(data).copy();
     }
-
-    /**
-     * Take a copy of this {@link UpgradeData}. This returns a new instance with the same upgrade and a fresh copy of
-     * the upgrade data.
-     *
-     * @return A copy of the current instance.
-     */
-    public UpgradeData<T> copy() {
-        return new UpgradeData<>(upgrade(), data().copy());
-    }
 }

projects/common-api/src/main/java/dan200/computercraft/api/upgrades/UpgradeSerialiser.java

@@ -12,7 +12,7 @@
 import dan200.computercraft.impl.upgrades.SerialiserWithCraftingItem;
 import dan200.computercraft.impl.upgrades.SimpleSerialiser;
 import net.minecraft.core.Registry;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.RecipeSerializer;
@@ -58,7 +58,7 @@ public interface UpgradeSerialiser<T extends UpgradeBase> {
      * @param buffer The buffer object to read this upgrade from.
      * @return The constructed upgrade, with a {@link UpgradeBase#getUpgradeID()} equal to {@code id}.
      */
-    T fromNetwork(ResourceLocation id, FriendlyByteBuf buffer);
+    T fromNetwork(ResourceLocation id, RegistryFriendlyByteBuf buffer);
 
     /**
      * Write this upgrade to a network packet, to be sent to the client.
@@ -66,7 +66,7 @@ public interface UpgradeSerialiser<T extends UpgradeBase> {
      * @param buffer  The buffer object to write this upgrade to
      * @param upgrade The upgrade to write.
      */
-    void toNetwork(FriendlyByteBuf buffer, T upgrade);
+    void toNetwork(RegistryFriendlyByteBuf buffer, T upgrade);
 
     /**
      * Create an upgrade serialiser for a simple upgrade. This is similar to a {@link SimpleCraftingRecipeSerializer},

projects/common-api/src/main/java/dan200/computercraft/impl/upgrades/SerialiserWithCraftingItem.java

@@ -7,7 +7,7 @@
 import com.google.gson.JsonObject;
 import dan200.computercraft.api.upgrades.UpgradeBase;
 import dan200.computercraft.api.upgrades.UpgradeSerialiser;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.util.GsonHelper;
 import net.minecraft.world.item.ItemStack;
@@ -37,13 +37,13 @@ public T fromJson(ResourceLocation id, JsonObject object) {
     }
 
     @Override
-    public T fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
-        var item = buffer.readItem();
+    public T fromNetwork(ResourceLocation id, RegistryFriendlyByteBuf buffer) {
+        var item = ItemStack.STREAM_CODEC.decode(buffer);
         return factory.apply(id, item);
     }
 
     @Override
-    public void toNetwork(FriendlyByteBuf buffer, T upgrade) {
-        buffer.writeItem(upgrade.getCraftingItem());
+    public void toNetwork(RegistryFriendlyByteBuf buffer, T upgrade) {
+        ItemStack.STREAM_CODEC.encode(buffer, upgrade.getCraftingItem());
     }
 }

projects/common-api/src/main/java/dan200/computercraft/impl/upgrades/SimpleSerialiser.java

@@ -7,7 +7,7 @@
 import com.google.gson.JsonObject;
 import dan200.computercraft.api.upgrades.UpgradeBase;
 import dan200.computercraft.api.upgrades.UpgradeSerialiser;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.ApiStatus;
 
@@ -34,11 +34,11 @@ public T fromJson(ResourceLocation id, JsonObject object) {
     }
 
     @Override
-    public T fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
+    public T fromNetwork(ResourceLocation id, RegistryFriendlyByteBuf buffer) {
         return constructor.apply(id);
     }
 
     @Override
-    public void toNetwork(FriendlyByteBuf buffer, T upgrade) {
+    public void toNetwork(RegistryFriendlyByteBuf buffer, T upgrade) {
     }
 }

projects/common/build.gradle.kts

@@ -23,7 +23,7 @@ configurations {
 }
 
 repositories {
-    maven("https://maven.minecraftforge.net/") {
+    maven("https://maven.neoforged.net/") {
         content {
             includeModule("org.spongepowered", "mixin")
         }
@@ -37,6 +37,7 @@ dependencies {
     clientImplementation(clientClasses(project(":common-api")))
 
     compileOnly(libs.mixin)
+    compileOnly(libs.mixinExtra)
     compileOnly(libs.bundles.externalMods.common)
     clientCompileOnly(variantOf(libs.emi) { classifier("api") })
 

projects/common/src/client/java/dan200/computercraft/client/ClientRegistry.java

@@ -21,13 +21,11 @@
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.command.CommandComputerCraft;
-import dan200.computercraft.shared.common.IColouredItem;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.computer.inventory.AbstractComputerMenu;
 import dan200.computercraft.shared.computer.inventory.ViewComputerMenu;
 import dan200.computercraft.shared.media.items.DiskItem;
-import dan200.computercraft.shared.media.items.TreasureDiskItem;
 import net.minecraft.Util;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.color.item.ItemColor;
@@ -44,11 +42,13 @@
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.PreparableReloadListener;
 import net.minecraft.server.packs.resources.ResourceProvider;
+import net.minecraft.util.FastColor;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.level.ItemLike;
 
 import javax.annotation.Nullable;
@@ -94,7 +94,7 @@ public static void registerMainThread(RegisterItemProperty itemProperties) {
             ModRegistry.Items.POCKET_COMPUTER_NORMAL, ModRegistry.Items.POCKET_COMPUTER_ADVANCED
         );
         registerItemProperty(itemProperties, "coloured",
-            (stack, world, player, random) -> IColouredItem.getColourBasic(stack) != -1 ? 1 : 0,
+            (stack, world, player, random) -> DyedItemColor.getOrDefault(stack, -1) != -1 ? 1 : 0,
             ModRegistry.Items.POCKET_COMPUTER_NORMAL, ModRegistry.Items.POCKET_COMPUTER_ADVANCED
         );
     }
@@ -162,12 +162,12 @@ public static void registerExtraModels(Consumer<ResourceLocation> register) {
 
     public static void registerItemColours(BiConsumer<ItemColor, ItemLike> register) {
         register.accept(
-            (stack, layer) -> layer == 1 ? ((DiskItem) stack.getItem()).getColour(stack) : 0xFFFFFF,
+            (stack, layer) -> layer == 1 ? DiskItem.getColour(stack) : -1,
             ModRegistry.Items.DISK.get()
         );
 
         register.accept(
-            (stack, layer) -> layer == 1 ? TreasureDiskItem.getColour(stack) : 0xFFFFFF,
+            (stack, layer) -> layer == 1 ? DyedItemColor.getOrDefault(stack, Colour.BLUE.getARGB()) : -1,
             ModRegistry.Items.TREASURE_DISK.get()
         );
 
@@ -180,17 +180,17 @@ public static void registerItemColours(BiConsumer<ItemColor, ItemLike> register)
 
     private static int getPocketColour(ItemStack stack, int layer) {
         return switch (layer) {
-            default -> 0xFFFFFF;
-            case 1 -> IColouredItem.getColourBasic(stack); // Frame colour
+            default -> -1;
+            case 1 -> DyedItemColor.getOrDefault(stack, -1); // Frame colour
             case 2 -> { // Light colour
                 var computer = ClientPocketComputers.get(stack);
-                yield computer == null || computer.getLightState() == -1 ? Colour.BLACK.getHex() : computer.getLightState();
+                yield computer == null || computer.getLightState() == -1 ? Colour.BLACK.getARGB() : FastColor.ARGB32.opaque(computer.getLightState());
             }
         };
     }
 
     private static int getTurtleColour(ItemStack stack, int layer) {
-        return layer == 0 ? ((IColouredItem) stack.getItem()).getColour(stack) : 0xFFFFFF;
+        return layer == 0 ? DyedItemColor.getOrDefault(stack, -1) : -1;
     }
 
     public static void registerShaders(ResourceProvider resources, BiConsumer<ShaderInstance, Consumer<ShaderInstance>> load) throws IOException {

projects/common/src/client/java/dan200/computercraft/client/ClientTableFormatter.java

@@ -75,7 +75,7 @@ public void display(TableBuilder table) {
 
         var tag = createTag(table.getId());
         if (chat.allMessages.removeIf(guiMessage -> guiMessage.tag() != null && Objects.equals(guiMessage.tag().logTag(), tag.logTag()))) {
-            chat.refreshTrimmedMessage();
+            chat.resetChatScroll();
         }
 
         TableFormatter.super.display(table);

projects/common/src/client/java/dan200/computercraft/client/gui/ClientInputHandler.java

@@ -49,31 +49,31 @@ public void queueEvent(String event, @Nullable Object[] arguments) {
 
     @Override
     public void keyDown(int key, boolean repeat) {
-        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.TYPE_REPEAT : KeyEventServerMessage.TYPE_DOWN, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.Action.REPEAT : KeyEventServerMessage.Action.DOWN, key));
     }
 
     @Override
     public void keyUp(int key) {
-        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.TYPE_UP, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.Action.UP, key));
     }
 
     @Override
     public void mouseClick(int button, int x, int y) {
-        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_CLICK, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.Action.CLICK, button, x, y));
     }
 
     @Override
     public void mouseUp(int button, int x, int y) {
-        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_UP, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.Action.UP, button, x, y));
     }
 
     @Override
     public void mouseDrag(int button, int x, int y) {
-        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_DRAG, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.Action.DRAG, button, x, y));
     }
 
     @Override
     public void mouseScroll(int direction, int x, int y) {
-        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_SCROLL, direction, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.Action.SCROLL, direction, x, y));
     }
 }

projects/common/src/client/java/dan200/computercraft/client/gui/PrintoutScreen.java

@@ -6,7 +6,9 @@
 
 import com.mojang.blaze3d.vertex.Tesselator;
 import dan200.computercraft.core.terminal.TextBuffer;
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.common.HeldItemMenu;
+import dan200.computercraft.shared.media.items.PrintoutData;
 import dan200.computercraft.shared.media.items.PrintoutItem;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
@@ -35,13 +37,14 @@ public PrintoutScreen(HeldItemMenu container, Inventory player, Component title)
 
         imageHeight = Y_SIZE;
 
-        var text = PrintoutItem.getText(container.getStack());
-        this.text = new TextBuffer[text.length];
-        for (var i = 0; i < this.text.length; i++) this.text[i] = new TextBuffer(text[i]);
-
-        var colours = PrintoutItem.getColours(container.getStack());
-        this.colours = new TextBuffer[colours.length];
-        for (var i = 0; i < this.colours.length; i++) this.colours[i] = new TextBuffer(colours[i]);
+        var printout = container.getStack().getOrDefault(ModRegistry.DataComponents.PRINTOUT.get(), PrintoutData.EMPTY);
+        this.text = new TextBuffer[printout.lines().size()];
+        this.colours = new TextBuffer[printout.lines().size()];
+        for (var i = 0; i < this.text.length; i++) {
+            var line = printout.lines().get(i);
+            this.text[i] = new TextBuffer(line.text());
+            this.colours[i] = new TextBuffer(line.foreground());
+        }
 
         page = 0;
         pages = Math.max(this.text.length / PrintoutItem.LINES_PER_PAGE, 1);

projects/common/src/client/java/dan200/computercraft/client/integration/emi/EMIComputerCraft.java

@@ -27,13 +27,11 @@ public void register(EmiRegistry registry) {
         registry.setDefaultComparison(ModRegistry.Items.POCKET_COMPUTER_ADVANCED.get(), pocketComparison);
     }
 
-    private static final Comparison turtleComparison = compareStacks((left, right) ->
-        left.getItem() instanceof TurtleItem turtle
-            && turtle.getUpgrade(left, TurtleSide.LEFT) == turtle.getUpgrade(right, TurtleSide.LEFT)
-            && turtle.getUpgrade(left, TurtleSide.RIGHT) == turtle.getUpgrade(right, TurtleSide.RIGHT));
+    private static final Comparison turtleComparison = compareStacks((left, right)
+        -> TurtleItem.getUpgrade(left, TurtleSide.LEFT) == TurtleItem.getUpgrade(right, TurtleSide.LEFT)
+        && TurtleItem.getUpgrade(left, TurtleSide.RIGHT) == TurtleItem.getUpgrade(right, TurtleSide.RIGHT));
 
-    private static final Comparison pocketComparison = compareStacks((left, right) ->
-        left.getItem() instanceof PocketComputerItem && PocketComputerItem.getUpgrade(left) == PocketComputerItem.getUpgrade(right));
+    private static final Comparison pocketComparison = compareStacks((left, right) -> PocketComputerItem.getUpgrade(left) == PocketComputerItem.getUpgrade(right));
 
     private static Comparison compareStacks(BiPredicate<ItemStack, ItemStack> test) {
         return Comparison.of((left, right) -> {

projects/common/src/client/java/dan200/computercraft/client/model/turtle/TurtleModelParts.java

@@ -15,9 +15,11 @@
 import dan200.computercraft.client.render.TurtleBlockEntityRenderer;
 import dan200.computercraft.client.turtle.TurtleUpgradeModellers;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import dan200.computercraft.shared.util.Holiday;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.resources.model.BakedModel;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 
@@ -54,13 +56,6 @@ private record Combination(
         boolean christmas,
         boolean flip
     ) {
-        Combination copy() {
-            if (leftUpgrade == null && rightUpgrade == null) return this;
-            return new Combination(
-                colour, UpgradeData.copyOf(leftUpgrade), UpgradeData.copyOf(rightUpgrade),
-                overlay, christmas, flip
-            );
-        }
     }
 
     private final BakedModel familyModel;
@@ -96,31 +91,18 @@ public TurtleModelParts(BakedModel familyModel, BakedModel colourModel, ModelTra
 
     public T getModel(ItemStack stack) {
         var combination = getCombination(stack);
-        var existing = modelCache.get(combination);
-        if (existing != null) return existing;
-
-        // Take a defensive copy of the upgrade data, and add it to the cache.
-        var newCombination = combination.copy();
-        var newModel = buildModel.apply(newCombination);
-        modelCache.put(newCombination, newModel);
-        return newModel;
+        return modelCache.computeIfAbsent(combination, buildModel);
     }
 
     private Combination getCombination(ItemStack stack) {
         var christmas = Holiday.getCurrent() == Holiday.CHRISTMAS;
-
-        if (!(stack.getItem() instanceof TurtleItem turtle)) {
-            return new Combination(false, null, null, null, christmas, false);
-        }
-
-        var colour = turtle.getColour(stack);
-        var leftUpgrade = turtle.getUpgradeWithData(stack, TurtleSide.LEFT);
-        var rightUpgrade = turtle.getUpgradeWithData(stack, TurtleSide.RIGHT);
-        var overlay = turtle.getOverlay(stack);
-        var label = turtle.getLabel(stack);
+        var leftUpgrade = TurtleItem.getUpgradeWithData(stack, TurtleSide.LEFT);
+        var rightUpgrade = TurtleItem.getUpgradeWithData(stack, TurtleSide.RIGHT);
+        var overlay = TurtleItem.getOverlay(stack);
+        var label = DataComponentUtil.getCustomName(stack);
         var flip = label != null && (label.equals("Dinnerbone") || label.equals("Grumm"));
 
-        return new Combination(colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip);
+        return new Combination(stack.has(DataComponents.DYED_COLOR), leftUpgrade, rightUpgrade, overlay, christmas, flip);
     }
 
     private List<BakedModel> buildModel(Combination combo) {

projects/common/src/client/java/dan200/computercraft/client/network/ClientNetworking.java

@@ -4,10 +4,10 @@
 
 package dan200.computercraft.client.network;
 
-import dan200.computercraft.client.platform.ClientPlatformHelper;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.server.ServerNetworkContext;
 import net.minecraft.client.Minecraft;
+import net.minecraft.network.protocol.common.ServerboundCustomPayloadPacket;
 
 /**
  * Methods for sending packets from clients to the server.
@@ -23,6 +23,6 @@ private ClientNetworking() {
      */
     public static void sendToServer(NetworkMessage<ServerNetworkContext> message) {
         var connection = Minecraft.getInstance().getConnection();
-        if (connection != null) connection.send(ClientPlatformHelper.get().createPacket(message));
+        if (connection != null) connection.send(new ServerboundCustomPayloadPacket(message));
     }
 }

projects/common/src/client/java/dan200/computercraft/client/platform/ClientPlatformHelper.java

@@ -5,13 +5,9 @@
 package dan200.computercraft.client.platform;
 
 import com.mojang.blaze3d.vertex.PoseStack;
-import dan200.computercraft.shared.network.NetworkMessage;
-import dan200.computercraft.shared.network.server.ServerNetworkContext;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.resources.model.BakedModel;
 import net.minecraft.core.BlockPos;
-import net.minecraft.network.protocol.Packet;
-import net.minecraft.network.protocol.common.ServerCommonPacketListener;
 import net.minecraft.sounds.SoundEvent;
 
 import javax.annotation.Nullable;
@@ -21,14 +17,6 @@ static ClientPlatformHelper get() {
         return (ClientPlatformHelper) dan200.computercraft.impl.client.ClientPlatformHelper.get();
     }
 
-    /**
-     * Convert a serverbound {@link NetworkMessage} to a Minecraft {@link Packet}.
-     *
-     * @param message The messsge to convert.
-     * @return The converted message.
-     */
-    Packet<ServerCommonPacketListener> createPacket(NetworkMessage<ServerNetworkContext> message);
-
     /**
      * Render a {@link BakedModel}, using any loader-specific hooks.
      *

projects/common/src/client/java/dan200/computercraft/client/pocket/ClientPocketComputers.java

@@ -4,11 +4,11 @@
 
 package dan200.computercraft.client.pocket;
 
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.client.PocketComputerDataMessage;
-import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import net.minecraft.world.item.ItemStack;
 
 import javax.annotation.Nullable;
@@ -53,7 +53,7 @@ public static void setState(UUID instanceId, ComputerState state, int lightColou
     }
 
     public static @Nullable PocketComputerData get(ItemStack stack) {
-        var id = PocketComputerItem.getInstanceID(stack);
-        return id == null ? null : instances.get(id);
+        var id = stack.get(ModRegistry.DataComponents.COMPUTER.get());
+        return id == null ? null : instances.get(id.instance());
     }
 }

projects/common/src/client/java/dan200/computercraft/client/render/CableHighlightRenderer.java

@@ -51,7 +51,6 @@ public static boolean drawHighlight(PoseStack transform, MultiBufferSource buffe
 
         var buffer = bufferSource.getBuffer(RenderType.lines());
         var matrix4f = transform.last().pose();
-        var normal = transform.last().normal();
         // TODO: Can we just accesstransformer out LevelRenderer.renderShape?
         shape.forAllEdges((x1, y1, z1, x2, y2, z2) -> {
             var xDelta = (float) (x2 - x1);
@@ -65,12 +64,12 @@ public static boolean drawHighlight(PoseStack transform, MultiBufferSource buffe
             buffer
                 .vertex(matrix4f, (float) (x1 + xOffset), (float) (y1 + yOffset), (float) (z1 + zOffset))
                 .color(0, 0, 0, 0.4f)
-                .normal(normal, xDelta, yDelta, zDelta)
+                .normal(transform.last(), xDelta, yDelta, zDelta)
                 .endVertex();
             buffer
                 .vertex(matrix4f, (float) (x2 + xOffset), (float) (y2 + yOffset), (float) (z2 + zOffset))
                 .color(0, 0, 0, 0.4f)
-                .normal(normal, xDelta, yDelta, zDelta)
+                .normal(transform.last(), xDelta, yDelta, zDelta)
                 .endVertex();
         });
 

projects/common/src/client/java/dan200/computercraft/client/render/PocketItemRenderer.java

@@ -15,6 +15,7 @@
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.DyedItemColor;
 import org.joml.Matrix4f;
 
 import static dan200.computercraft.client.render.ComputerBorderRenderer.*;
@@ -61,7 +62,7 @@ protected void renderItem(PoseStack transform, MultiBufferSource bufferSource, I
         // Render the main frame
         var item = (PocketComputerItem) stack.getItem();
         var family = item.getFamily();
-        var frameColour = item.getColour(stack);
+        var frameColour = DyedItemColor.getOrDefault(stack, -1);
 
         var matrix = transform.last().pose();
         renderFrame(matrix, bufferSource, family, frameColour, light, width, height);

projects/common/src/client/java/dan200/computercraft/client/render/PrintoutItemRenderer.java

@@ -6,6 +6,8 @@
 
 import com.mojang.blaze3d.vertex.PoseStack;
 import com.mojang.math.Axis;
+import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.media.items.PrintoutData;
 import dan200.computercraft.shared.media.items.PrintoutItem;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.world.entity.EntityType;
@@ -37,8 +39,6 @@ protected void renderItem(PoseStack transform, MultiBufferSource render, ItemSta
     }
 
     public static void onRenderInFrame(PoseStack transform, MultiBufferSource render, ItemFrame frame, ItemStack stack, int packedLight) {
-        if (!(stack.getItem() instanceof PrintoutItem)) return;
-
         // Move a little bit forward to ensure we're not clipping with the frame
         transform.translate(0.0f, 0.0f, -0.001f);
         transform.mulPose(Axis.ZP.rotationDegrees(180f));
@@ -50,7 +50,9 @@ public static void onRenderInFrame(PoseStack transform, MultiBufferSource render
     }
 
     private static void drawPrintout(PoseStack transform, MultiBufferSource render, ItemStack stack, int light) {
-        var pages = PrintoutItem.getPageCount(stack);
+        var pageData = stack.getOrDefault(ModRegistry.DataComponents.PRINTOUT.get(), PrintoutData.EMPTY);
+
+        var pages = pageData.pages();
         var book = ((PrintoutItem) stack.getItem()).getType() == PrintoutItem.Type.BOOK;
 
         double width = LINE_MAX_LENGTH * FONT_WIDTH + X_TEXT_MARGIN * 2;
@@ -75,9 +77,6 @@ private static void drawPrintout(PoseStack transform, MultiBufferSource render,
         transform.translate((max - width) / 2.0, (max - height) / 2.0, 0.0);
 
         drawBorder(transform, render, 0, 0, -0.01f, 0, pages, book, light);
-        drawText(
-            transform, render, X_TEXT_MARGIN, Y_TEXT_MARGIN, 0, light,
-            PrintoutItem.getText(stack), PrintoutItem.getColours(stack)
-        );
+        drawText(transform, render, X_TEXT_MARGIN, Y_TEXT_MARGIN, 0, light, pageData.lines());
     }
 }

projects/common/src/client/java/dan200/computercraft/client/render/PrintoutRenderer.java

@@ -9,9 +9,12 @@
 import dan200.computercraft.client.render.text.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Palette;
 import dan200.computercraft.core.terminal.TextBuffer;
+import dan200.computercraft.shared.media.items.PrintoutData;
 import net.minecraft.client.renderer.MultiBufferSource;
 import org.joml.Matrix4f;
 
+import java.util.List;
+
 import static dan200.computercraft.client.render.text.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.shared.media.items.PrintoutItem.LINES_PER_PAGE;
 
@@ -69,13 +72,14 @@ public static void drawText(PoseStack transform, MultiBufferSource bufferSource,
         }
     }
 
-    public static void drawText(PoseStack transform, MultiBufferSource bufferSource, int x, int y, int start, int light, String[] text, String[] colours) {
+    public static void drawText(PoseStack transform, MultiBufferSource bufferSource, int x, int y, int start, int light, List<PrintoutData.Line> lines) {
         var buffer = bufferSource.getBuffer(RenderTypes.PRINTOUT_TEXT);
         var emitter = FixedWidthFontRenderer.toVertexConsumer(transform, buffer);
-        for (var line = 0; line < LINES_PER_PAGE && line < text.length; line++) {
+        for (var line = 0; line < LINES_PER_PAGE && line < lines.size(); line++) {
+            var lineContents = lines.get(start + line);
             FixedWidthFontRenderer.drawString(emitter,
                 x, y + line * FONT_HEIGHT,
-                new TextBuffer(text[start + line]), new TextBuffer(colours[start + line]),
+                new TextBuffer(lineContents.text()), new TextBuffer(lineContents.foreground()),
                 Palette.DEFAULT, light
             );
         }

projects/common/src/client/java/dan200/computercraft/client/render/monitor/MonitorBlockEntityRenderer.java

@@ -191,17 +191,23 @@ private static void renderTerminal(
                     });
                 }
 
-                // Our VBO doesn't transform its vertices with the provided pose stack, which means that the inverse view
-                // rotation matrix gives entirely wrong numbers for fog distances. We just set it to the identity which
-                // gives a good enough approximation.
-                var oldInverseRotation = RenderSystem.getInverseViewRotationMatrix();
-                RenderSystem.setInverseViewRotationMatrix(IDENTITY_NORMAL);
+                // Our VBO renders coordinates in monitor-space rather than world space. A full sized monitor (8x6) will
+                // use positions from (0, 0) to (164*FONT_WIDTH, 81*FONT_HEIGHT) = (984, 729). This is far outside the
+                // normal render distance (~200), and the edges of the monitor fade out due to fog.
+                // There's not really a good way around this, at least without using a custom render type (which the VBO
+                // renderer is trying to avoid!). Instead, we just disable fog entirely by setting the fog start to an
+                // absurdly high value.
+                var oldFogStart = RenderSystem.getShaderFogStart();
+                RenderSystem.setShaderFogStart(1e4f);
 
                 RenderTypes.TERMINAL.setupRenderState();
 
+                // Compose the existing model view matrix with our transformation matrix.
+                var modelView = new Matrix4f(RenderSystem.getModelViewMatrix()).mul(matrix);
+
                 // Render background geometry
                 backgroundBuffer.bind();
-                backgroundBuffer.drawWithShader(matrix, RenderSystem.getProjectionMatrix(), RenderTypes.getTerminalShader());
+                backgroundBuffer.drawWithShader(modelView, RenderSystem.getProjectionMatrix(), RenderTypes.getTerminalShader());
 
                 // Render foreground geometry with glPolygonOffset enabled.
                 RenderSystem.polygonOffset(-1.0f, -10.0f);
@@ -209,7 +215,7 @@ private static void renderTerminal(
 
                 foregroundBuffer.bind();
                 foregroundBuffer.drawWithShader(
-                    matrix, RenderSystem.getProjectionMatrix(), RenderTypes.getTerminalShader(),
+                    modelView, RenderSystem.getProjectionMatrix(), RenderTypes.getTerminalShader(),
                     // As mentioned in the above comment, render the extra cursor quad if it is visible this frame. Each
                     // // quad has an index count of 6.
                     FixedWidthFontRenderer.isCursorVisible(terminal) && FrameInfo.getGlobalCursorBlink()
@@ -222,7 +228,7 @@ private static void renderTerminal(
                 RenderTypes.TERMINAL.clearRenderState();
                 VertexBuffer.unbind();
 
-                RenderSystem.setInverseViewRotationMatrix(oldInverseRotation);
+                RenderSystem.setShaderFogStart(oldFogStart);
             }
             case BEST -> throw new IllegalStateException("Impossible: Should never use BEST renderer");
         }

projects/common/src/client/java/dan200/computercraft/client/render/monitor/MonitorHighlightRenderer.java

@@ -12,7 +12,6 @@
 import net.minecraft.client.renderer.RenderType;
 import net.minecraft.core.Direction;
 import net.minecraft.world.phys.BlockHitResult;
-import org.joml.Matrix3f;
 import org.joml.Matrix4f;
 
 import java.util.EnumSet;
@@ -53,7 +52,7 @@ public static boolean drawHighlight(PoseStack transformStack, MultiBufferSource
         // I wish I could think of a better way to do this
         var buffer = bufferSource.getBuffer(RenderType.lines());
         var transform = transformStack.last().pose();
-        var normal = transformStack.last().normal();
+        var normal = transformStack.last();
         if (faces.contains(NORTH) || faces.contains(WEST)) line(buffer, transform, normal, 0, 0, 0, UP);
         if (faces.contains(SOUTH) || faces.contains(WEST)) line(buffer, transform, normal, 0, 0, 1, UP);
         if (faces.contains(NORTH) || faces.contains(EAST)) line(buffer, transform, normal, 1, 0, 0, UP);
@@ -71,7 +70,7 @@ public static boolean drawHighlight(PoseStack transformStack, MultiBufferSource
         return true;
     }
 
-    private static void line(VertexConsumer buffer, Matrix4f transform, Matrix3f normal, float x, float y, float z, Direction direction) {
+    private static void line(VertexConsumer buffer, Matrix4f transform, PoseStack.Pose normal, float x, float y, float z, Direction direction) {
         buffer
             .vertex(transform, x, y, z)
             .color(0, 0, 0, 0.4f)

projects/common/src/client/java/dan200/computercraft/client/turtle/TurtleModemModeller.java

@@ -9,8 +9,9 @@
 import dan200.computercraft.api.client.turtle.TurtleUpgradeModeller;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.TurtleSide;
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.turtle.upgrades.TurtleModem;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.Nullable;
 
@@ -41,12 +42,9 @@ public TurtleModemModeller(boolean advanced) {
     }
 
     @Override
-    public TransformedModel getModel(TurtleModem upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, CompoundTag data) {
-        var active = false;
-        if (turtle != null) {
-            var turtleNBT = turtle.getUpgradeNBTData(side);
-            active = turtleNBT.contains("active") && turtleNBT.getBoolean("active");
-        }
+    public TransformedModel getModel(TurtleModem upgrade, @Nullable ITurtleAccess turtle, TurtleSide side, DataComponentPatch data) {
+        var component = data.get(ModRegistry.DataComponents.ON.get());
+        var active = component != null && component.isPresent() && component.get();
 
         return side == TurtleSide.LEFT
             ? TransformedModel.of(active ? leftOnModel : leftOffModel)

projects/common/src/client/java/dan200/computercraft/client/turtle/TurtleUpgradeModellers.java

@@ -15,7 +15,7 @@
 import dan200.computercraft.impl.TurtleUpgrades;
 import dan200.computercraft.impl.UpgradeManager;
 import net.minecraft.client.Minecraft;
-import net.minecraft.nbt.CompoundTag;
+import net.minecraft.core.component.DataComponentPatch;
 import net.minecraft.resources.ResourceLocation;
 
 import java.util.Map;
@@ -60,10 +60,10 @@ public static <T extends ITurtleUpgrade> void register(UpgradeSerialiser<T> seri
     public static TransformedModel getModel(ITurtleUpgrade upgrade, ITurtleAccess access, TurtleSide side) {
         @SuppressWarnings("unchecked")
         var modeller = (TurtleUpgradeModeller<ITurtleUpgrade>) modelCache.computeIfAbsent(upgrade, TurtleUpgradeModellers::getModeller);
-        return modeller.getModel(upgrade, access, side, access.getUpgradeNBTData(side));
+        return modeller.getModel(upgrade, access, side, access.getUpgradeData(side));
     }
 
-    public static TransformedModel getModel(ITurtleUpgrade upgrade, CompoundTag data, TurtleSide side) {
+    public static TransformedModel getModel(ITurtleUpgrade upgrade, DataComponentPatch data, TurtleSide side) {
         @SuppressWarnings("unchecked")
         var modeller = (TurtleUpgradeModeller<ITurtleUpgrade>) modelCache.computeIfAbsent(upgrade, TurtleUpgradeModellers::getModeller);
         return modeller.getModel(upgrade, null, side, data);

projects/common/src/main/java/dan200/computercraft/data/DataProviders.java

@@ -5,6 +5,7 @@
 package dan200.computercraft.data;
 
 import com.mojang.serialization.Codec;
+import net.minecraft.core.HolderLookup;
 import net.minecraft.data.DataProvider;
 import net.minecraft.data.PackOutput;
 import net.minecraft.data.loot.LootTableProvider.SubProviderEntry;
@@ -17,7 +18,9 @@
 import net.minecraft.world.level.block.Block;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 
 /**
@@ -31,7 +34,7 @@ private DataProviders() {
     public static void add(GeneratorSink generator) {
         var turtleUpgrades = generator.add(TurtleUpgradeProvider::new);
         var pocketUpgrades = generator.add(PocketUpgradeProvider::new);
-        generator.add(out -> new RecipeProvider(out, turtleUpgrades, pocketUpgrades));
+        generator.add((out, registries) -> new RecipeProvider(out, registries, turtleUpgrades, pocketUpgrades));
 
         var blockTags = generator.blockTags(TagProvider::blockTags);
         generator.itemTags(TagProvider::itemTags, blockTags);
@@ -55,6 +58,8 @@ public static void add(GeneratorSink generator) {
     public interface GeneratorSink {
         <T extends DataProvider> T add(DataProvider.Factory<T> factory);
 
+        <T extends DataProvider> T add(BiFunction<PackOutput, CompletableFuture<HolderLookup.Provider>, T> factory);
+
         <T> void addFromCodec(String name, PackType type, String directory, Codec<T> codec, Consumer<BiConsumer<ResourceLocation, T>> output);
 
         void lootTable(List<SubProviderEntry> tables);

projects/common/src/main/java/dan200/computercraft/data/LootTableProvider.java

@@ -13,7 +13,9 @@
 import dan200.computercraft.shared.peripheral.modem.wired.CableBlock;
 import dan200.computercraft.shared.peripheral.modem.wired.CableModemVariant;
 import net.minecraft.advancements.critereon.StatePropertiesPredicate;
+import net.minecraft.core.HolderLookup;
 import net.minecraft.data.loot.LootTableProvider.SubProviderEntry;
+import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.storage.loot.LootPool;
@@ -41,7 +43,7 @@ public static List<SubProviderEntry> getTables() {
         );
     }
 
-    private static void registerBlocks(BiConsumer<ResourceLocation, LootTable.Builder> add) {
+    private static void registerBlocks(HolderLookup.Provider registries, BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add) {
         namedBlockDrop(add, ModRegistry.Blocks.DISK_DRIVE);
         selfDrop(add, ModRegistry.Blocks.MONITOR_NORMAL);
         selfDrop(add, ModRegistry.Blocks.MONITOR_ADVANCED);
@@ -78,15 +80,15 @@ private static void registerBlocks(BiConsumer<ResourceLocation, LootTable.Builde
             ));
     }
 
-    private static void registerGeneric(BiConsumer<ResourceLocation, LootTable.Builder> add) {
+    private static void registerGeneric(HolderLookup.Provider registries, BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add) {
         add.accept(CommonHooks.TREASURE_DISK_LOOT, LootTable.lootTable());
     }
 
-    private static void selfDrop(BiConsumer<ResourceLocation, LootTable.Builder> add, Supplier<? extends Block> wrapper) {
+    private static void selfDrop(BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add, Supplier<? extends Block> wrapper) {
         blockDrop(add, wrapper, LootItem.lootTableItem(wrapper.get()), ExplosionCondition.survivesExplosion());
     }
 
-    private static void namedBlockDrop(BiConsumer<ResourceLocation, LootTable.Builder> add, Supplier<? extends Block> wrapper) {
+    private static void namedBlockDrop(BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add, Supplier<? extends Block> wrapper) {
         blockDrop(
             add, wrapper,
             LootItem.lootTableItem(wrapper.get()).apply(CopyNameFunction.copyName(CopyNameFunction.NameSource.BLOCK_ENTITY)),
@@ -94,7 +96,7 @@ private static void namedBlockDrop(BiConsumer<ResourceLocation, LootTable.Builde
         );
     }
 
-    private static void computerDrop(BiConsumer<ResourceLocation, LootTable.Builder> add, Supplier<? extends Block> block) {
+    private static void computerDrop(BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add, Supplier<? extends Block> block) {
         blockDrop(
             add, block,
             DynamicLoot.dynamicEntry(new ResourceLocation(ComputerCraftAPI.MOD_ID, "computer")),
@@ -107,7 +109,7 @@ private static void computerDrop(BiConsumer<ResourceLocation, LootTable.Builder>
     }
 
     private static void blockDrop(
-        BiConsumer<ResourceLocation, LootTable.Builder> add, Supplier<? extends Block> wrapper,
+        BiConsumer<ResourceKey<LootTable>, LootTable.Builder> add, Supplier<? extends Block> wrapper,
         LootPoolEntryContainer.Builder<?> drop,
         LootItemCondition.Builder condition
     ) {

projects/common/src/main/java/dan200/computercraft/data/RecipeProvider.java

@@ -5,7 +5,6 @@
 package dan200.computercraft.data;
 
 import com.google.gson.JsonObject;
-import com.google.gson.JsonParseException;
 import com.mojang.authlib.GameProfile;
 import com.mojang.serialization.JsonOps;
 import dan200.computercraft.api.ComputerCraftAPI;
@@ -19,26 +18,25 @@
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.common.ClearColourRecipe;
 import dan200.computercraft.shared.common.ColourableRecipe;
-import dan200.computercraft.shared.computer.recipe.ComputerUpgradeRecipe;
-import dan200.computercraft.shared.media.items.DiskItem;
+import dan200.computercraft.shared.computer.recipe.ComputerConvertRecipe;
 import dan200.computercraft.shared.media.recipes.DiskRecipe;
 import dan200.computercraft.shared.media.recipes.PrintoutRecipe;
 import dan200.computercraft.shared.platform.PlatformHelper;
 import dan200.computercraft.shared.platform.RecipeIngredients;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.pocket.recipes.PocketComputerUpgradeRecipe;
-import dan200.computercraft.shared.recipe.CustomShapelessRecipe;
 import dan200.computercraft.shared.recipe.ImpostorShapedRecipe;
 import dan200.computercraft.shared.recipe.ImpostorShapelessRecipe;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
 import dan200.computercraft.shared.turtle.recipes.TurtleOverlayRecipe;
-import dan200.computercraft.shared.turtle.recipes.TurtleRecipe;
 import dan200.computercraft.shared.turtle.recipes.TurtleUpgradeRecipe;
 import dan200.computercraft.shared.util.ColourUtils;
-import net.minecraft.Util;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import net.minecraft.advancements.Criterion;
 import net.minecraft.advancements.critereon.InventoryChangeTrigger;
 import net.minecraft.advancements.critereon.ItemPredicate;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.data.PackOutput;
@@ -46,12 +44,13 @@
 import net.minecraft.data.recipes.RecipeOutput;
 import net.minecraft.data.recipes.ShapedRecipeBuilder;
 import net.minecraft.data.recipes.ShapelessRecipeBuilder;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtUtils;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.tags.ItemTags;
 import net.minecraft.tags.TagKey;
 import net.minecraft.util.GsonHelper;
 import net.minecraft.world.item.*;
+import net.minecraft.world.item.component.DyedItemColor;
+import net.minecraft.world.item.component.ResolvableProfile;
 import net.minecraft.world.item.crafting.CraftingBookCategory;
 import net.minecraft.world.item.crafting.Ingredient;
 import net.minecraft.world.item.crafting.Recipe;
@@ -60,6 +59,7 @@
 
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
 
 import static dan200.computercraft.api.ComputerCraftTags.Items.COMPUTER;
@@ -70,8 +70,8 @@ final class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
     private final TurtleUpgradeDataProvider turtleUpgrades;
     private final PocketUpgradeDataProvider pocketUpgrades;
 
-    RecipeProvider(PackOutput output, TurtleUpgradeDataProvider turtleUpgrades, PocketUpgradeDataProvider pocketUpgrades) {
-        super(output);
+    RecipeProvider(PackOutput output, CompletableFuture<HolderLookup.Provider> registries, TurtleUpgradeDataProvider turtleUpgrades, PocketUpgradeDataProvider pocketUpgrades) {
+        super(output, registries);
         this.turtleUpgrades = turtleUpgrades;
         this.pocketUpgrades = pocketUpgrades;
     }
@@ -100,7 +100,7 @@ public void buildRecipes(RecipeOutput add) {
     private void diskColours(RecipeOutput output) {
         for (var colour : Colour.VALUES) {
             ShapelessSpecBuilder
-                .shapeless(RecipeCategory.REDSTONE, DiskItem.createFromIDAndColour(-1, null, colour.getHex()))
+                .shapeless(RecipeCategory.REDSTONE, DataComponentUtil.createStack(ModRegistry.Items.DISK.get(), DataComponents.DYED_COLOR, new DyedItemColor(colour.getHex(), false)))
                 .requires(ingredients.redstone())
                 .requires(Items.PAPER)
                 .requires(DyeItem.byColor(ofColour(colour)))
@@ -122,17 +122,16 @@ private static List<TurtleItem> turtleItems() {
      */
     private void turtleUpgrades(RecipeOutput add) {
         for (var turtleItem : turtleItems()) {
-            var base = turtleItem.create(-1, null, -1, null, null, 0, null);
             var name = RegistryHelper.getKeyOrThrow(BuiltInRegistries.ITEM, turtleItem);
 
             for (var upgrade : turtleUpgrades.getGeneratedUpgrades()) {
                 ShapedSpecBuilder
-                    .shaped(RecipeCategory.REDSTONE, turtleItem.create(-1, null, -1, null, UpgradeData.ofDefault(upgrade), -1, null))
+                    .shaped(RecipeCategory.REDSTONE, DataComponentUtil.createStack(turtleItem, ModRegistry.DataComponents.RIGHT_TURTLE_UPGRADE.get(), UpgradeData.ofDefault(upgrade)))
                     .group(name.toString())
                     .pattern("#T")
-                    .define('T', base.getItem())
+                    .define('T', turtleItem)
                     .define('#', upgrade.getCraftingItem().getItem())
-                    .unlockedBy("has_items", inventoryChange(base.getItem(), upgrade.getCraftingItem().getItem()))
+                    .unlockedBy("has_items", inventoryChange(turtleItem, upgrade.getCraftingItem().getItem()))
                     .build(ImpostorShapedRecipe::new)
                     .save(
                         add,
@@ -153,18 +152,17 @@ private static List<PocketComputerItem> pocketComputerItems() {
      */
     private void pocketUpgrades(RecipeOutput add) {
         for (var pocket : pocketComputerItems()) {
-            var base = pocket.create(-1, null, -1, null);
             var name = RegistryHelper.getKeyOrThrow(BuiltInRegistries.ITEM, pocket).withPath(x -> x.replace("pocket_computer_", "pocket_"));
 
             for (var upgrade : pocketUpgrades.getGeneratedUpgrades()) {
                 ShapedSpecBuilder
-                    .shaped(RecipeCategory.REDSTONE, pocket.create(-1, null, -1, UpgradeData.ofDefault(upgrade)))
+                    .shaped(RecipeCategory.REDSTONE, DataComponentUtil.createStack(pocket, ModRegistry.DataComponents.POCKET_UPGRADE.get(), UpgradeData.ofDefault(upgrade)))
                     .group(name.toString())
                     .pattern("#")
                     .pattern("P")
-                    .define('P', base.getItem())
+                    .define('P', pocket)
                     .define('#', upgrade.getCraftingItem().getItem())
-                    .unlockedBy("has_items", inventoryChange(base.getItem(), upgrade.getCraftingItem().getItem()))
+                    .unlockedBy("has_items", inventoryChange(pocket, upgrade.getCraftingItem().getItem()))
                     .build(ImpostorShapedRecipe::new)
                     .save(
                         add,
@@ -197,15 +195,14 @@ private void turtleOverlays(RecipeOutput add) {
 
     private void turtleOverlay(RecipeOutput add, String overlay, Consumer<ShapelessSpecBuilder> build) {
         for (var turtleItem : turtleItems()) {
-            var base = turtleItem.create(-1, null, -1, null, null, 0, null);
             var name = RegistryHelper.getKeyOrThrow(BuiltInRegistries.ITEM, turtleItem);
 
-            var builder = ShapelessSpecBuilder.shapeless(RecipeCategory.REDSTONE, base)
+            var builder = ShapelessSpecBuilder.shapeless(RecipeCategory.REDSTONE, new ItemStack(turtleItem))
                 .group(name.withSuffix("_overlay").toString())
-                .unlockedBy("has_turtle", inventoryChange(base.getItem()));
+                .unlockedBy("has_turtle", inventoryChange(turtleItem));
             build.accept(builder);
             builder
-                .requires(base.getItem())
+                .requires(turtleItem)
                 .build(s -> new TurtleOverlayRecipe(s, new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/" + overlay)))
                 .save(add, name.withSuffix("_overlays/" + overlay));
         }
@@ -254,7 +251,7 @@ private void basicRecipes(RecipeOutput add) {
             .define('#', ingredients.goldIngot())
             .define('C', ModRegistry.Items.COMPUTER_NORMAL.get())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.COMPUTER_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
-            .build(ComputerUpgradeRecipe::new)
+            .build(ComputerConvertRecipe::new)
             .save(add, new ResourceLocation(ComputerCraftAPI.MOD_ID, "computer_advanced_upgrade"));
 
         ShapedRecipeBuilder
@@ -277,7 +274,7 @@ private void basicRecipes(RecipeOutput add) {
             .define('C', ModRegistry.Items.COMPUTER_NORMAL.get())
             .define('I', ingredients.woodenChest())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_NORMAL.get()))
-            .buildOrThrow(TurtleRecipe::of)
+            .build(ComputerConvertRecipe::new)
             .save(add);
 
         ShapedSpecBuilder
@@ -289,7 +286,7 @@ private void basicRecipes(RecipeOutput add) {
             .define('C', ModRegistry.Items.COMPUTER_ADVANCED.get())
             .define('I', ingredients.woodenChest())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_NORMAL.get()))
-            .buildOrThrow(TurtleRecipe::of)
+            .build(ComputerConvertRecipe::new)
             .save(add);
 
         ShapedSpecBuilder
@@ -301,7 +298,7 @@ private void basicRecipes(RecipeOutput add) {
             .define('C', ModRegistry.Items.TURTLE_NORMAL.get())
             .define('B', ingredients.goldBlock())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.TURTLE_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
-            .build(ComputerUpgradeRecipe::new)
+            .build(ComputerConvertRecipe::new)
             .save(add, new ResourceLocation(ComputerCraftAPI.MOD_ID, "turtle_advanced_upgrade"));
 
         ShapedRecipeBuilder
@@ -366,7 +363,7 @@ private void basicRecipes(RecipeOutput add) {
             .define('#', ingredients.goldIngot())
             .define('C', ModRegistry.Items.POCKET_COMPUTER_NORMAL.get())
             .unlockedBy("has_components", inventoryChange(itemPredicate(ModRegistry.Items.POCKET_COMPUTER_NORMAL.get()), itemPredicate(ingredients.goldIngot())))
-            .build(ComputerUpgradeRecipe::new)
+            .build(ComputerConvertRecipe::new)
             .save(add, new ResourceLocation(ComputerCraftAPI.MOD_ID, "pocket_computer_advanced_upgrade"));
 
         ShapedRecipeBuilder
@@ -436,18 +433,18 @@ private void basicRecipes(RecipeOutput add) {
 
         ShapelessSpecBuilder
             .shapeless(RecipeCategory.DECORATIONS, playerHead("Cloudhunter", "6d074736-b1e9-4378-a99b-bd8777821c9c"))
-            .requires(ingredients.head())
+            .requires(ItemTags.SKULLS)
             .requires(ModRegistry.Items.MONITOR_NORMAL.get())
             .unlockedBy("has_monitor", inventoryChange(ModRegistry.Items.MONITOR_NORMAL.get()))
-            .build(CustomShapelessRecipe::new)
+            .build()
             .save(add, new ResourceLocation(ComputerCraftAPI.MOD_ID, "skull_cloudy"));
 
         ShapelessSpecBuilder
             .shapeless(RecipeCategory.DECORATIONS, playerHead("dan200", "f3c8d69b-0776-4512-8434-d1b2165909eb"))
-            .requires(ingredients.head())
+            .requires(ItemTags.SKULLS)
             .requires(ModRegistry.Items.COMPUTER_ADVANCED.get())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_ADVANCED.get()))
-            .build(CustomShapelessRecipe::new)
+            .build()
             .save(add, new ResourceLocation(ComputerCraftAPI.MOD_ID, "skull_dan200"));
 
         ShapelessSpecBuilder
@@ -493,11 +490,11 @@ private static ItemPredicate itemPredicate(TagKey<Item> item) {
     }
 
     private static ItemPredicate itemPredicate(Ingredient ingredient) {
-        var json = Util.getOrThrow(Ingredient.CODEC_NONEMPTY.encodeStart(JsonOps.INSTANCE, ingredient), JsonParseException::new);
+        var json = Ingredient.CODEC_NONEMPTY.encodeStart(JsonOps.INSTANCE, ingredient).getOrThrow();
         if (!(json instanceof JsonObject object)) throw new IllegalStateException("Unknown ingredient " + json);
 
         if (object.has("item")) {
-            var item = Util.getOrThrow(ItemStack.ITEM_WITH_COUNT_CODEC.parse(JsonOps.INSTANCE, object), JsonParseException::new);
+            var item = ItemStack.SIMPLE_ITEM_CODEC.parse(JsonOps.INSTANCE, object).getOrThrow();
             return itemPredicate(item.getItem());
         } else if (object.has("tag")) {
             return itemPredicate(TagKey.create(Registries.ITEM, new ResourceLocation(GsonHelper.getAsString(object, "tag"))));
@@ -507,10 +504,7 @@ private static ItemPredicate itemPredicate(Ingredient ingredient) {
     }
 
     private static ItemStack playerHead(String name, String uuid) {
-        var item = new ItemStack(Items.PLAYER_HEAD);
-        var owner = NbtUtils.writeGameProfile(new CompoundTag(), new GameProfile(UUID.fromString(uuid), name));
-        item.getOrCreateTag().put(PlayerHeadItem.TAG_SKULL_OWNER, owner);
-        return item;
+        return DataComponentUtil.createStack(Items.PLAYER_HEAD, DataComponents.PROFILE, new ResolvableProfile(new GameProfile(UUID.fromString(uuid), name)));
     }
 
     private static void addSpecial(RecipeOutput add, Recipe<?> recipe) {

projects/common/src/main/java/dan200/computercraft/data/TagProvider.java

@@ -7,8 +7,8 @@
 import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.impl.RegistryHelper;
 import dan200.computercraft.shared.ModRegistry;
-import net.minecraft.core.Registry;
 import dan200.computercraft.shared.integration.ExternalModTags;
+import net.minecraft.core.Registry;
 import net.minecraft.data.tags.ItemTagsProvider;
 import net.minecraft.data.tags.TagsProvider;
 import net.minecraft.tags.BlockTags;
@@ -97,6 +97,10 @@ public static void itemTags(ItemTagConsumer tags) {
         tags.tag(ComputerCraftTags.Items.WIRED_MODEM).add(ModRegistry.Items.WIRED_MODEM.get(), ModRegistry.Items.WIRED_MODEM_FULL.get());
         tags.copy(ComputerCraftTags.Blocks.MONITOR, ComputerCraftTags.Items.MONITOR);
 
+        tags.tag(ComputerCraftTags.Items.DYEABLE)
+            .addTag(ComputerCraftTags.Items.TURTLE)
+            .add(ModRegistry.Items.DISK.get(), ModRegistry.Items.POCKET_COMPUTER_NORMAL.get(), ModRegistry.Items.POCKET_COMPUTER_ADVANCED.get());
+
         tags.tag(ItemTags.PIGLIN_LOVED).add(
             ModRegistry.Items.COMPUTER_ADVANCED.get(), ModRegistry.Items.TURTLE_ADVANCED.get(),
             ModRegistry.Items.WIRELESS_MODEM_ADVANCED.get(), ModRegistry.Items.POCKET_COMPUTER_ADVANCED.get(),

projects/common/src/main/java/dan200/computercraft/data/recipe/AbstractRecipeBuilder.java

@@ -6,7 +6,6 @@
 
 import com.mojang.serialization.DataResult;
 import dan200.computercraft.shared.recipe.RecipeProperties;
-import net.minecraft.Util;
 import net.minecraft.advancements.AdvancementRequirements;
 import net.minecraft.advancements.AdvancementRewards;
 import net.minecraft.advancements.Criterion;
@@ -90,7 +89,7 @@ public final FinishedRecipe build(Function<O, Recipe<?>> factory) {
      * @return The "built" recipe.
      */
     public final FinishedRecipe buildOrThrow(Function<O, DataResult<? extends Recipe<?>>> factory) {
-        return build(s -> Util.getOrThrow(factory.apply(s), IllegalStateException::new));
+        return build(s -> factory.apply(s).getOrThrow());
     }
 
     @SuppressWarnings("unchecked")

projects/common/src/main/java/dan200/computercraft/data/recipe/ShapelessSpecBuilder.java

@@ -13,6 +13,7 @@
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.Ingredient;
+import net.minecraft.world.item.crafting.ShapelessRecipe;
 import net.minecraft.world.level.ItemLike;
 
 /**
@@ -58,4 +59,8 @@ public ShapelessSpecBuilder requires(TagKey<Item> item) {
     protected ShapelessRecipeSpec build(RecipeProperties properties) {
         return new ShapelessRecipeSpec(properties, ingredients, result);
     }
+
+    public FinishedRecipe build() {
+        return build(spec -> new ShapelessRecipe(spec.properties().group(), spec.properties().category(), spec.result(), spec.ingredients()));
+    }
 }

projects/common/src/main/java/dan200/computercraft/impl/UpgradeManager.java

@@ -5,12 +5,19 @@
 package dan200.computercraft.impl;
 
 import com.google.gson.*;
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.upgrades.UpgradeBase;
 import dan200.computercraft.api.upgrades.UpgradeData;
 import dan200.computercraft.api.upgrades.UpgradeSerialiser;
 import dan200.computercraft.shared.platform.PlatformHelper;
+import io.netty.buffer.ByteBuf;
 import net.minecraft.core.Registry;
+import net.minecraft.core.component.DataComponentPatch;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.ResourceManager;
@@ -40,16 +47,46 @@ public class UpgradeManager<T extends UpgradeBase> extends SimpleJsonResourceRel
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
 
     public record UpgradeWrapper<T extends UpgradeBase>(
-        String id, T upgrade, UpgradeSerialiser<? extends T> serialiser, String modId
+        ResourceLocation id, T upgrade, UpgradeSerialiser<? extends T> serialiser, String modId
     ) {
     }
 
     private final String kind;
     private final ResourceKey<Registry<UpgradeSerialiser<? extends T>>> registry;
 
-    private Map<String, UpgradeWrapper<T>> current = Map.of();
+    private Map<ResourceLocation, UpgradeWrapper<T>> current = Map.of();
     private Map<T, UpgradeWrapper<T>> currentWrappers = Map.of();
 
+    private final Codec<T> upgradeCodec = ResourceLocation.CODEC.flatXmap(
+        x -> {
+            var upgrade = get(x);
+            return upgrade == null ? DataResult.error(() -> "Unknown upgrade " + x) : DataResult.success(upgrade);
+        },
+        x -> DataResult.success(x.getUpgradeID())
+    );
+
+    private final Codec<UpgradeData<T>> fullCodec = RecordCodecBuilder.create(i -> i.group(
+        upgradeCodec.fieldOf("id").forGetter(UpgradeData::upgrade),
+        DataComponentPatch.CODEC.optionalFieldOf("components", DataComponentPatch.EMPTY).forGetter(UpgradeData::data)
+    ).apply(i, UpgradeData::new));
+
+    private final Codec<UpgradeData<T>> codec = Codec.withAlternative(fullCodec, upgradeCodec, UpgradeData::ofDefault);
+
+    private final StreamCodec<ByteBuf, T> upgradeStreamCodec = ResourceLocation.STREAM_CODEC.map(
+        x -> {
+            var upgrade = get(x);
+            if (upgrade == null) throw new IllegalStateException("Unknown upgrade " + x);
+            return upgrade;
+        },
+        UpgradeBase::getUpgradeID
+    );
+
+    private final StreamCodec<RegistryFriendlyByteBuf, UpgradeData<T>> streamCodec = StreamCodec.composite(
+        upgradeStreamCodec, UpgradeData::upgrade,
+        DataComponentPatch.STREAM_CODEC, UpgradeData::data,
+        UpgradeData::new
+    );
+
     public UpgradeManager(String kind, String path, ResourceKey<Registry<UpgradeSerialiser<? extends T>>> registry) {
         super(GSON, path);
         this.kind = kind;
@@ -57,7 +94,7 @@ public UpgradeManager(String kind, String path, ResourceKey<Registry<UpgradeSeri
     }
 
     @Nullable
-    public T get(String id) {
+    public T get(ResourceLocation id) {
         var wrapper = current.get(id);
         return wrapper == null ? null : wrapper.upgrade();
     }
@@ -91,14 +128,22 @@ public Collection<T> getUpgrades() {
         return currentWrappers.keySet();
     }
 
-    public Map<String, UpgradeWrapper<T>> getUpgradeWrappers() {
+    public Map<ResourceLocation, UpgradeWrapper<T>> getUpgradeWrappers() {
         return current;
     }
 
+    public Codec<UpgradeData<T>> codec() {
+        return codec;
+    }
+
+    public StreamCodec<RegistryFriendlyByteBuf, UpgradeData<T>> streamCodec() {
+        return streamCodec;
+    }
+
     @Override
     protected void apply(Map<ResourceLocation, JsonElement> upgrades, ResourceManager manager, ProfilerFiller profiler) {
         var registry = RegistryHelper.getRegistry(this.registry);
-        Map<String, UpgradeWrapper<T>> newUpgrades = new HashMap<>();
+        Map<ResourceLocation, UpgradeWrapper<T>> newUpgrades = new HashMap<>();
         for (var element : upgrades.entrySet()) {
             try {
                 loadUpgrade(registry, newUpgrades, element.getKey(), element.getValue());
@@ -112,7 +157,7 @@ protected void apply(Map<ResourceLocation, JsonElement> upgrades, ResourceManage
         LOG.info("Loaded {} {}s", current.size(), kind);
     }
 
-    private void loadUpgrade(Registry<UpgradeSerialiser<? extends T>> registry, Map<String, UpgradeWrapper<T>> current, ResourceLocation id, JsonElement json) {
+    private void loadUpgrade(Registry<UpgradeSerialiser<? extends T>> registry, Map<ResourceLocation, UpgradeWrapper<T>> current, ResourceLocation id, JsonElement json) {
         var root = GsonHelper.convertToJsonObject(json, "top element");
         if (!PlatformHelper.get().shouldLoadResource(root)) return;
 
@@ -130,11 +175,11 @@ private void loadUpgrade(Registry<UpgradeSerialiser<? extends T>> registry, Map<
             throw new IllegalArgumentException("Upgrade " + id + " from " + serialiser + " was incorrectly given id " + upgrade.getUpgradeID());
         }
 
-        var result = new UpgradeWrapper<T>(id.toString(), upgrade, serialiser, modId);
+        var result = new UpgradeWrapper<T>(id, upgrade, serialiser, modId);
         current.put(result.id(), result);
     }
 
-    public void loadFromNetwork(Map<String, UpgradeWrapper<T>> newUpgrades) {
+    public void loadFromNetwork(Map<ResourceLocation, UpgradeWrapper<T>> newUpgrades) {
         current = Collections.unmodifiableMap(newUpgrades);
         currentWrappers = newUpgrades.values().stream().collect(Collectors.toUnmodifiableMap(UpgradeWrapper::upgrade, x -> x));
     }

projects/common/src/main/java/dan200/computercraft/mixin/ItemStackComponentizationFixMixin.java

@@ -0,0 +1,49 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.mixin;
+
+import com.llamalad7.mixinextras.injector.ModifyReturnValue;
+import com.mojang.datafixers.DataFix;
+import com.mojang.datafixers.TypeRewriteRule;
+import com.mojang.datafixers.schemas.Schema;
+import com.mojang.serialization.Dynamic;
+import dan200.computercraft.shared.util.ComponentizationFixers;
+import net.minecraft.util.datafix.fixes.ItemStackComponentizationFix;
+import net.minecraft.util.datafix.fixes.References;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+/**
+ * Migrates CC's item NBT to use components.
+ *
+ * @see V3818_3Mixin
+ * @see ComponentizationFixers
+ */
+@Mixin(ItemStackComponentizationFix.class)
+abstract class ItemStackComponentizationFixMixin extends DataFix {
+    @SuppressWarnings("UnusedMethod")
+    private ItemStackComponentizationFixMixin(Schema outputSchema, boolean changesType) {
+        super(outputSchema, changesType);
+    }
+
+    @Inject(method = "fixItemStack", at = @At("TAIL"))
+    @SuppressWarnings("UnusedMethod")
+    private static void fixItemStack(ItemStackComponentizationFix.ItemStackData data, Dynamic<?> ops, CallbackInfo ci) {
+        ComponentizationFixers.fixItemComponents(data, ops);
+    }
+
+    @ModifyReturnValue(method = "makeRule", at = @At("RETURN"), remap = false)
+    @SuppressWarnings("UnusedMethod")
+    private TypeRewriteRule wrapMakeRule(TypeRewriteRule existing) {
+        return TypeRewriteRule.seq(existing, fixTypeEverywhereTyped(
+            "Turtle upgrade componentization",
+            getInputSchema().getType(References.BLOCK_ENTITY),
+            getOutputSchema().getType(References.BLOCK_ENTITY),
+            ComponentizationFixers.makeBlockEntityRewrites(getInputSchema(), getOutputSchema())
+        ));
+    }
+}

projects/common/src/main/java/dan200/computercraft/mixin/V1460Mixin.java

@@ -7,16 +7,17 @@
 import com.mojang.datafixers.DSL;
 import com.mojang.datafixers.schemas.Schema;
 import com.mojang.datafixers.types.templates.TypeTemplate;
-import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.peripheral.diskdrive.DiskDriveBlockEntity;
 import dan200.computercraft.shared.peripheral.printer.PrinterBlockEntity;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlockEntity;
 import net.minecraft.util.datafix.fixes.References;
+import net.minecraft.util.datafix.schemas.NamespacedSchema;
 import net.minecraft.util.datafix.schemas.V1460;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 import java.util.Map;
@@ -37,16 +38,34 @@ private void registerBlockEntities(Schema schema, CallbackInfoReturnable<Map<Str
         var map = ci.getReturnValue();
 
         // Basic inventories
-        registerInventory(schema, map, ModRegistry.BlockEntities.TURTLE_NORMAL.id().toString());
-        registerInventory(schema, map, ModRegistry.BlockEntities.TURTLE_ADVANCED.id().toString());
-        registerInventory(schema, map, ModRegistry.BlockEntities.PRINTER.id().toString());
+        registerTurtle(schema, map, "computercraft:turtle_normal");
+        registerTurtle(schema, map, "computercraft:turtle_advanced");
+        registerInventory(schema, map, "computercraft:printer");
 
         // Disk drives contain a single item
-        schema.register(map, ModRegistry.BlockEntities.DISK_DRIVE.id().toString(), () -> DSL.optionalFields(
+        schema.register(map, "computercraft:disk_drive", () -> DSL.optionalFields(
             "Item", References.ITEM_STACK.in(schema)
         ));
     }
 
+    private static TypeTemplate upgradeData(Schema schema) {
+        return DSL.or(
+            // Pre-1.20.5 we just use the upgrade ID.
+            DSL.constType(NamespacedSchema.namespacedString()),
+            // In newer versions this is represented as a component.
+            DSL.optionalFields("components", References.DATA_COMPONENTS.in(schema))
+        );
+    }
+
+    @Unique
+    private static void registerTurtle(Schema schema, Map<String, Supplier<TypeTemplate>> map, String name) {
+        schema.register(map, name, () -> DSL.optionalFields(
+            "LeftUpgrade", upgradeData(schema),
+            "RightUpgrade", upgradeData(schema),
+            "Items", DSL.list(References.ITEM_STACK.in(schema))
+        ));
+    }
+
     @Shadow
     protected static void registerInventory(Schema schema, Map<String, Supplier<TypeTemplate>> map, String name) {
     }

projects/common/src/main/java/dan200/computercraft/mixin/V3818_3Mixin.java

@@ -0,0 +1,57 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.mixin;
+
+import com.llamalad7.mixinextras.injector.ModifyReturnValue;
+import com.mojang.datafixers.DSL;
+import com.mojang.datafixers.schemas.Schema;
+import com.mojang.datafixers.types.templates.TypeTemplate;
+import com.mojang.datafixers.util.Pair;
+import dan200.computercraft.impl.UpgradeManager;
+import dan200.computercraft.shared.ModRegistry.DataComponents;
+import net.minecraft.util.datafix.fixes.References;
+import net.minecraft.util.datafix.schemas.V3818_3;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+import java.util.Arrays;
+import java.util.stream.Stream;
+
+/**
+ * Add our custom data components to the datafixer system.
+ *
+ * @see UpgradeManager#codec()
+ * @see DataComponents#POCKET_UPGRADE
+ * @see DataComponents#LEFT_TURTLE_UPGRADE
+ * @see DataComponents#RIGHT_TURTLE_UPGRADE
+ * @see ItemStackComponentizationFixMixin
+ */
+@Mixin(V3818_3.class)
+class V3818_3Mixin {
+    @ModifyReturnValue(
+        method = "method_57277",
+        at = @At("TAIL")
+    )
+    @SuppressWarnings("UnusedMethod")
+    private static TypeTemplate addExtraTypes(TypeTemplate type, Schema schema) {
+        // Create a codec for UpgradeData
+        var upgradeData = DSL.optionalFields("components", References.DATA_COMPONENTS.in(schema));
+
+        return extraOptionalFields(type,
+            Pair.of("computercraft:upgrade", upgradeData),
+            Pair.of("computercraft:left_upgrade", upgradeData),
+            Pair.of("computercraft:right_upgrade", upgradeData)
+        );
+    }
+
+    @SafeVarargs
+    @SuppressWarnings("varargs")
+    private static TypeTemplate extraOptionalFields(TypeTemplate base, Pair<String, TypeTemplate>... fields) {
+        return DSL.and(Stream.concat(
+            Arrays.stream(fields).map(entry -> DSL.optional(DSL.field(entry.getFirst(), entry.getSecond()))),
+            Stream.of(base)
+        ).toList());
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/CommonHooks.java

@@ -14,6 +14,7 @@
 import dan200.computercraft.shared.peripheral.monitor.MonitorWatcher;
 import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.TickScheduler;
+import net.minecraft.core.registries.Registries;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
@@ -28,7 +29,8 @@
 import net.minecraft.world.level.chunk.LevelChunk;
 import net.minecraft.world.level.storage.loot.BuiltInLootTables;
 import net.minecraft.world.level.storage.loot.LootPool;
-import net.minecraft.world.level.storage.loot.entries.LootTableReference;
+import net.minecraft.world.level.storage.loot.LootTable;
+import net.minecraft.world.level.storage.loot.entries.NestedLootTable;
 import net.minecraft.world.level.storage.loot.providers.number.ConstantValue;
 
 import javax.annotation.Nullable;
@@ -92,9 +94,9 @@ public static void onChunkTicketLevelChanged(ServerLevel level, long chunkPos, i
         TickScheduler.onChunkTicketChanged(level, chunkPos, oldLevel, newLevel);
     }
 
-    public static final ResourceLocation TREASURE_DISK_LOOT = new ResourceLocation(ComputerCraftAPI.MOD_ID, "treasure_disk");
+    public static final ResourceKey<LootTable> TREASURE_DISK_LOOT = ResourceKey.create(Registries.LOOT_TABLE, new ResourceLocation(ComputerCraftAPI.MOD_ID, "treasure_disk"));
 
-    private static final Set<ResourceLocation> TREASURE_DISK_LOOT_TABLES = Set.of(
+    private static final Set<ResourceKey<LootTable>> TREASURE_DISK_LOOT_TABLES = Set.of(
         BuiltInLootTables.SIMPLE_DUNGEON,
         BuiltInLootTables.ABANDONED_MINESHAFT,
         BuiltInLootTables.STRONGHOLD_CORRIDOR,
@@ -107,13 +109,13 @@ public static void onChunkTicketLevelChanged(ServerLevel level, long chunkPos, i
         BuiltInLootTables.VILLAGE_CARTOGRAPHER
     );
 
-    public static @Nullable LootPool.Builder getExtraLootPool(ResourceLocation lootTable) {
-        if (!lootTable.getNamespace().equals("minecraft") || !TREASURE_DISK_LOOT_TABLES.contains(lootTable)) {
+    public static @Nullable LootPool.Builder getExtraLootPool(ResourceKey<LootTable> lootTable) {
+        if (!TREASURE_DISK_LOOT_TABLES.contains(lootTable)) {
             return null;
         }
 
         return LootPool.lootPool()
-            .add(LootTableReference.lootTableReference(TREASURE_DISK_LOOT))
+            .add(NestedLootTable.lootTableReference(TREASURE_DISK_LOOT))
             .setRolls(ConstantValue.exactly(1));
     }
 

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -6,6 +6,8 @@
 
 import com.mojang.brigadier.arguments.ArgumentType;
 import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.MapCodec;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.detail.DetailProvider;
 import dan200.computercraft.api.detail.VanillaDetailRegistries;
@@ -33,8 +35,10 @@
 import dan200.computercraft.shared.computer.inventory.ComputerMenuWithoutInventory;
 import dan200.computercraft.shared.computer.inventory.ViewComputerMenu;
 import dan200.computercraft.shared.computer.items.CommandComputerItem;
+import dan200.computercraft.shared.computer.items.ComputerId;
 import dan200.computercraft.shared.computer.items.ComputerItem;
-import dan200.computercraft.shared.computer.recipe.ComputerUpgradeRecipe;
+import dan200.computercraft.shared.computer.items.ServerComputerReference;
+import dan200.computercraft.shared.computer.recipe.ComputerConvertRecipe;
 import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
 import dan200.computercraft.shared.data.HasComputerIdLootCondition;
@@ -42,10 +46,7 @@
 import dan200.computercraft.shared.details.BlockDetails;
 import dan200.computercraft.shared.details.ItemDetails;
 import dan200.computercraft.shared.integration.PermissionRegistry;
-import dan200.computercraft.shared.media.items.DiskItem;
-import dan200.computercraft.shared.media.items.PrintoutItem;
-import dan200.computercraft.shared.media.items.RecordMedia;
-import dan200.computercraft.shared.media.items.TreasureDiskItem;
+import dan200.computercraft.shared.media.items.*;
 import dan200.computercraft.shared.media.recipes.DiskRecipe;
 import dan200.computercraft.shared.media.recipes.PrintoutRecipe;
 import dan200.computercraft.shared.network.container.ComputerContainerData;
@@ -81,19 +82,22 @@
 import dan200.computercraft.shared.turtle.inventory.TurtleMenu;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
 import dan200.computercraft.shared.turtle.recipes.TurtleOverlayRecipe;
-import dan200.computercraft.shared.turtle.recipes.TurtleRecipe;
 import dan200.computercraft.shared.turtle.recipes.TurtleUpgradeRecipe;
 import dan200.computercraft.shared.turtle.upgrades.*;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.commands.synchronization.ArgumentTypeInfo;
 import net.minecraft.commands.synchronization.SingletonArgumentInfo;
-import net.minecraft.core.BlockPos;
 import net.minecraft.core.cauldron.CauldronInteraction;
+import net.minecraft.core.component.DataComponentType;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.network.chat.Component;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.flag.FeatureFlags;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.*;
+import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.item.crafting.CustomRecipe;
 import net.minecraft.world.item.crafting.RecipeSerializer;
 import net.minecraft.world.item.crafting.SimpleCraftingRecipeSerializer;
@@ -101,12 +105,12 @@
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockBehaviour;
-import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.material.MapColor;
 import net.minecraft.world.level.storage.loot.predicates.LootItemConditionType;
 
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 
 /**
  * Registers ComputerCraft's registry entries and additional objects, such as {@link CauldronInteraction}s and
@@ -174,8 +178,8 @@ private static BlockBehaviour.Properties modemProperties() {
     public static class BlockEntities {
         static final RegistrationHelper<BlockEntityType<?>> REGISTRY = PlatformHelper.get().createRegistrationHelper(Registries.BLOCK_ENTITY_TYPE);
 
-        private static <T extends BlockEntity> RegistryEntry<BlockEntityType<T>> ofBlock(RegistryEntry<? extends Block> block, BiFunction<BlockPos, BlockState, T> factory) {
-            return REGISTRY.register(block.id().getPath(), () -> PlatformHelper.get().createBlockEntityType(factory, block.get()));
+        private static <T extends BlockEntity> RegistryEntry<BlockEntityType<T>> ofBlock(RegistryEntry<? extends Block> block, BlockEntityType.BlockEntitySupplier<T> factory) {
+            return REGISTRY.register(block.id().getPath(), () -> BlockEntityType.Builder.of(factory, block.get()).build(null));
         }
 
         public static final RegistryEntry<BlockEntityType<MonitorBlockEntity>> MONITOR_NORMAL =
@@ -262,6 +266,60 @@ private static <B extends Block, I extends Item> RegistryEntry<I> ofBlock(Regist
             () -> new CableBlockItem.WiredModem(Blocks.CABLE.get(), properties()));
     }
 
+    public static final class DataComponents {
+        static final RegistrationHelper<DataComponentType<?>> REGISTRY = PlatformHelper.get().createRegistrationHelper(Registries.DATA_COMPONENT_TYPE);
+
+        private static <T> RegistryEntry<DataComponentType<T>> register(String name, UnaryOperator<DataComponentType.Builder<T>> unaryOperator) {
+            return REGISTRY.register(name, () -> unaryOperator.apply(DataComponentType.builder()).build());
+        }
+
+        public static final RegistryEntry<DataComponentType<TreasureDisk>> TREASURE_DISK = register("treasure_disk", b -> b
+            .persistent(TreasureDisk.CODEC).networkSynchronized(TreasureDisk.STREAM_CODEC)
+        );
+
+        public static final RegistryEntry<DataComponentType<Integer>> DISK = register("disk", b -> b
+            // TODO: Replace with a normal object.
+            .persistent(Codec.INT.validate(x -> x < 0 ? DataResult.error(() -> "Disk ID must be >= 0") : DataResult.success(x)))
+            .networkSynchronized(ByteBufCodecs.INT)
+        );
+
+        public static final RegistryEntry<DataComponentType<ComputerId>> COMPUTER_ID = register("computer_id", b -> b
+            .persistent(ComputerId.CODEC).networkSynchronized(ComputerId.STREAM_CODEC)
+        );
+
+        public static final RegistryEntry<DataComponentType<UpgradeData<IPocketUpgrade>>> POCKET_UPGRADE = register("upgrade", b -> b
+            .persistent(PocketUpgrades.instance().codec()).networkSynchronized(PocketUpgrades.instance().streamCodec())
+        );
+
+        public static final RegistryEntry<DataComponentType<UpgradeData<ITurtleUpgrade>>> LEFT_TURTLE_UPGRADE = register("left_upgrade", b -> b
+            .persistent(TurtleUpgrades.instance().codec()).networkSynchronized(TurtleUpgrades.instance().streamCodec())
+        );
+
+        public static final RegistryEntry<DataComponentType<UpgradeData<ITurtleUpgrade>>> RIGHT_TURTLE_UPGRADE = register("right_upgrade", b -> b
+            .persistent(TurtleUpgrades.instance().codec()).networkSynchronized(TurtleUpgrades.instance().streamCodec())
+        );
+
+        public static final RegistryEntry<DataComponentType<ServerComputerReference>> COMPUTER = register("computer", b -> b
+            .persistent(ServerComputerReference.CODEC).networkSynchronized(ServerComputerReference.STREAM_CODEC)
+        );
+
+        public static final RegistryEntry<DataComponentType<Boolean>> ON = register("on", b -> b
+            .persistent(Codec.BOOL).networkSynchronized(ByteBufCodecs.BOOL)
+        );
+
+        public static final RegistryEntry<DataComponentType<Integer>> FUEL = register("fuel", b -> b
+            .persistent(Codec.INT).networkSynchronized(ByteBufCodecs.VAR_INT)
+        );
+
+        public static final RegistryEntry<DataComponentType<ResourceLocation>> OVERLAY = register("overlay", b -> b
+            .persistent(ResourceLocation.CODEC).networkSynchronized(ResourceLocation.STREAM_CODEC)
+        );
+
+        public static final RegistryEntry<DataComponentType<PrintoutData>> PRINTOUT = register("printout", b -> b
+            .persistent(PrintoutData.CODEC).networkSynchronized(PrintoutData.STREAM_CODEC)
+        );
+    }
+
     public static class TurtleSerialisers {
         static final RegistrationHelper<UpgradeSerialiser<? extends ITurtleUpgrade>> REGISTRY = PlatformHelper.get().createRegistrationHelper(ITurtleUpgrade.serialiserRegistryKey());
 
@@ -292,16 +350,16 @@ public static class Menus {
         static final RegistrationHelper<MenuType<?>> REGISTRY = PlatformHelper.get().createRegistrationHelper(Registries.MENU);
 
         public static final RegistryEntry<MenuType<ComputerMenuWithoutInventory>> COMPUTER = REGISTRY.register("computer",
-            () -> ContainerData.toType(ComputerContainerData::new, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.COMPUTER.get(), id, inv, data)));
+            () -> ContainerData.toType(ComputerContainerData.STREAM_CODEC, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.COMPUTER.get(), id, inv, data)));
 
         public static final RegistryEntry<MenuType<ComputerMenuWithoutInventory>> POCKET_COMPUTER = REGISTRY.register("pocket_computer",
-            () -> ContainerData.toType(ComputerContainerData::new, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.POCKET_COMPUTER.get(), id, inv, data)));
+            () -> ContainerData.toType(ComputerContainerData.STREAM_CODEC, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.POCKET_COMPUTER.get(), id, inv, data)));
 
         public static final RegistryEntry<MenuType<ComputerMenuWithoutInventory>> POCKET_COMPUTER_NO_TERM = REGISTRY.register("pocket_computer_no_term",
-            () -> ContainerData.toType(ComputerContainerData::new, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.POCKET_COMPUTER_NO_TERM.get(), id, inv, data)));
+            () -> ContainerData.toType(ComputerContainerData.STREAM_CODEC, (id, inv, data) -> new ComputerMenuWithoutInventory(Menus.POCKET_COMPUTER_NO_TERM.get(), id, inv, data)));
 
         public static final RegistryEntry<MenuType<TurtleMenu>> TURTLE = REGISTRY.register("turtle",
-            () -> ContainerData.toType(ComputerContainerData::new, TurtleMenu::ofMenuData));
+            () -> ContainerData.toType(ComputerContainerData.STREAM_CODEC, TurtleMenu::ofMenuData));
 
         public static final RegistryEntry<MenuType<DiskDriveMenu>> DISK_DRIVE = REGISTRY.register("disk_drive",
             () -> new MenuType<>(DiskDriveMenu::new, FeatureFlags.VANILLA_SET));
@@ -311,12 +369,12 @@ public static class Menus {
 
         public static final RegistryEntry<MenuType<HeldItemMenu>> PRINTOUT = REGISTRY.register("printout",
             () -> ContainerData.toType(
-                HeldItemContainerData::new,
+                HeldItemContainerData.STREAM_CODEC,
                 (id, inventory, data) -> new HeldItemMenu(Menus.PRINTOUT.get(), id, inventory.player, data.getHand())
             ));
 
         public static final RegistryEntry<MenuType<ViewComputerMenu>> VIEW_COMPUTER = REGISTRY.register("view_computer",
-            () -> ContainerData.toType(ComputerContainerData::new, ViewComputerMenu::new));
+            () -> ContainerData.toType(ComputerContainerData.STREAM_CODEC, ViewComputerMenu::new));
     }
 
     static class ArgumentTypes {
@@ -346,13 +404,13 @@ public static class LootItemConditionTypes {
         static final RegistrationHelper<LootItemConditionType> REGISTRY = PlatformHelper.get().createRegistrationHelper(Registries.LOOT_CONDITION_TYPE);
 
         public static final RegistryEntry<LootItemConditionType> BLOCK_NAMED = REGISTRY.register("block_named",
-            () -> new LootItemConditionType(Codec.unit(BlockNamedEntityLootCondition.INSTANCE)));
+            () -> new LootItemConditionType(MapCodec.unit(BlockNamedEntityLootCondition.INSTANCE)));
 
         public static final RegistryEntry<LootItemConditionType> PLAYER_CREATIVE = REGISTRY.register("player_creative",
-            () -> new LootItemConditionType(Codec.unit(PlayerCreativeLootCondition.INSTANCE)));
+            () -> new LootItemConditionType(MapCodec.unit(PlayerCreativeLootCondition.INSTANCE)));
 
         public static final RegistryEntry<LootItemConditionType> HAS_ID = REGISTRY.register("has_id",
-            () -> new LootItemConditionType(Codec.unit(HasComputerIdLootCondition.INSTANCE)));
+            () -> new LootItemConditionType(MapCodec.unit(HasComputerIdLootCondition.INSTANCE)));
     }
 
     public static class RecipeSerializers {
@@ -362,21 +420,17 @@ private static <T extends CustomRecipe> RegistryEntry<SimpleCraftingRecipeSerial
             return REGISTRY.register(name, () -> new SimpleCraftingRecipeSerializer<>(factory));
         }
 
-        public static final RegistryEntry<RecipeSerializer<CustomShapedRecipe>> SHAPED = REGISTRY.register("shaped", () -> CustomShapedRecipe.serialiser(CustomShapedRecipe::new));
-        public static final RegistryEntry<RecipeSerializer<CustomShapelessRecipe>> SHAPELESS = REGISTRY.register("shapeless", () -> CustomShapelessRecipe.serialiser(CustomShapelessRecipe::new));
-
         public static final RegistryEntry<RecipeSerializer<ImpostorShapedRecipe>> IMPOSTOR_SHAPED = REGISTRY.register("impostor_shaped", () -> CustomShapedRecipe.serialiser(ImpostorShapedRecipe::new));
         public static final RegistryEntry<RecipeSerializer<ImpostorShapelessRecipe>> IMPOSTOR_SHAPELESS = REGISTRY.register("impostor_shapeless", () -> CustomShapelessRecipe.serialiser(ImpostorShapelessRecipe::new));
 
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ColourableRecipe>> DYEABLE_ITEM = simple("colour", ColourableRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ClearColourRecipe>> DYEABLE_ITEM_CLEAR = simple("clear_colour", ClearColourRecipe::new);
-        public static final RegistryEntry<RecipeSerializer<TurtleRecipe>> TURTLE = REGISTRY.register("turtle", () -> TurtleRecipe.validatingSerialiser(TurtleRecipe::of));
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<TurtleUpgradeRecipe>> TURTLE_UPGRADE = simple("turtle_upgrade", TurtleUpgradeRecipe::new);
-        public static final RegistryEntry<RecipeSerializer<TurtleOverlayRecipe>> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe.Serialiser::new);
+        public static final RegistryEntry<RecipeSerializer<TurtleOverlayRecipe>> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe::serialiser);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PocketComputerUpgradeRecipe>> POCKET_COMPUTER_UPGRADE = simple("pocket_computer_upgrade", PocketComputerUpgradeRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PrintoutRecipe>> PRINTOUT = simple("printout", PrintoutRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<DiskRecipe>> DISK = simple("disk", DiskRecipe::new);
-        public static final RegistryEntry<RecipeSerializer<ComputerUpgradeRecipe>> COMPUTER_UPGRADE = REGISTRY.register("computer_upgrade", () -> CustomShapedRecipe.validatingSerialiser(ComputerUpgradeRecipe::of));
+        public static final RegistryEntry<RecipeSerializer<ComputerConvertRecipe>> COMPUTER_CONVERT = REGISTRY.register("computer_convert", () -> CustomShapedRecipe.serialiser(ComputerConvertRecipe::new));
     }
 
     public static class Permissions {
@@ -425,7 +479,7 @@ static class CreativeTabs {
 
                 out.accept(Items.DISK_DRIVE.get());
                 for (var colour = 0; colour < 16; colour++) {
-                    out.accept(DiskItem.createFromIDAndColour(-1, null, Colour.VALUES[colour].getHex()));
+                    out.accept(DataComponentUtil.createStack(Items.DISK.get(), net.minecraft.core.component.DataComponents.DYED_COLOR, new DyedItemColor(Colour.VALUES[colour].getHex(), false)));
                 }
             })
             .build());
@@ -438,6 +492,7 @@ public static void register() {
         Blocks.REGISTRY.register();
         BlockEntities.REGISTRY.register();
         Items.REGISTRY.register();
+        DataComponents.REGISTRY.register();
         TurtleSerialisers.REGISTRY.register();
         PocketUpgradeSerialisers.REGISTRY.register();
         Menus.REGISTRY.register();
@@ -470,14 +525,14 @@ public static void registerMainThread() {
     }
 
     private static void addTurtle(CreativeModeTab.Output out, TurtleItem turtle) {
-        out.accept(turtle.create(-1, null, -1, null, null, 0, null));
+        out.accept(new ItemStack(turtle));
         TurtleUpgrades.getVanillaUpgrades()
-            .map(x -> turtle.create(-1, null, -1, null, UpgradeData.ofDefault(x), 0, null))
+            .map(x -> DataComponentUtil.createStack(turtle, DataComponents.RIGHT_TURTLE_UPGRADE.get(), UpgradeData.ofDefault(x)))
             .forEach(out::accept);
     }
 
     private static void addPocket(CreativeModeTab.Output out, PocketComputerItem pocket) {
-        out.accept(pocket.create(-1, null, -1, null));
-        PocketUpgrades.getVanillaUpgrades().map(x -> pocket.create(-1, null, -1, UpgradeData.ofDefault(x))).forEach(out::accept);
+        out.accept(new ItemStack(pocket));
+        PocketUpgrades.getVanillaUpgrades().map(x -> DataComponentUtil.createStack(pocket, DataComponents.POCKET_UPGRADE.get(), UpgradeData.ofDefault(x))).forEach(out::accept);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/command/arguments/ArgumentUtils.java

@@ -14,8 +14,6 @@
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.chat.Component;
 
-import java.util.Objects;
-
 /**
  * Utilities for working with arguments.
  *
@@ -45,13 +43,12 @@ public static <A extends ArgumentType<?>> void serializeToNetwork(FriendlyByteBu
 
     @SuppressWarnings("unchecked")
     private static <A extends ArgumentType<?>, T extends ArgumentTypeInfo.Template<A>> void serializeToNetwork(FriendlyByteBuf buffer, ArgumentTypeInfo<A, T> type, ArgumentTypeInfo.Template<A> template) {
-        buffer.writeId(BuiltInRegistries.COMMAND_ARGUMENT_TYPE, type);
+        buffer.writeVarInt(BuiltInRegistries.COMMAND_ARGUMENT_TYPE.getIdOrThrow(type));
         type.serializeToNetwork((T) template, buffer);
     }
 
     public static ArgumentTypeInfo.Template<?> deserialize(FriendlyByteBuf buffer) {
-        var type = buffer.readById(BuiltInRegistries.COMMAND_ARGUMENT_TYPE);
-        Objects.requireNonNull(type, "Unknown argument type");
+        var type = BuiltInRegistries.COMMAND_ARGUMENT_TYPE.byIdOrThrow(buffer.readVarInt());
         return type.deserializeFromNetwork(buffer);
     }
 

projects/common/src/main/java/dan200/computercraft/shared/command/arguments/RepeatArgumentType.java

@@ -15,8 +15,10 @@
 import net.minecraft.commands.CommandBuildContext;
 import net.minecraft.commands.synchronization.ArgumentTypeInfo;
 import net.minecraft.commands.synchronization.ArgumentTypeInfos;
+import net.minecraft.core.RegistryAccess;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.ComponentSerialization;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -114,14 +116,14 @@ public static class Info implements ArgumentTypeInfo<RepeatArgumentType<?, ?>, T
         public void serializeToNetwork(RepeatArgumentType.Template arg, FriendlyByteBuf buf) {
             buf.writeBoolean(arg.flatten);
             ArgumentUtils.serializeToNetwork(buf, arg.child);
-            buf.writeComponent(ArgumentUtils.getMessage(arg.some));
+            ComponentSerialization.TRUSTED_CONTEXT_FREE_STREAM_CODEC.encode(buf, ArgumentUtils.getMessage(arg.some));
         }
 
         @Override
         public RepeatArgumentType.Template deserializeFromNetwork(FriendlyByteBuf buf) {
             var isList = buf.readBoolean();
             var child = ArgumentUtils.deserialize(buf);
-            var message = buf.readComponent();
+            var message = ComponentSerialization.TRUSTED_CONTEXT_FREE_STREAM_CODEC.decode(buf);
             return new RepeatArgumentType.Template(this, child, isList, new SimpleCommandExceptionType(message));
         }
 
@@ -134,7 +136,7 @@ public RepeatArgumentType.Template unpack(RepeatArgumentType<?, ?> argumentType)
         public void serializeToJson(RepeatArgumentType.Template arg, JsonObject json) {
             json.addProperty("flatten", arg.flatten);
             json.add("child", ArgumentUtils.serializeToJson(arg.child));
-            json.addProperty("error", Component.Serializer.toJson(ArgumentUtils.getMessage(arg.some)));
+            json.addProperty("error", Component.Serializer.toJson(ArgumentUtils.getMessage(arg.some), RegistryAccess.EMPTY));
         }
     }
 

projects/common/src/main/java/dan200/computercraft/shared/common/AbstractContainerBlockEntity.java

@@ -4,11 +4,8 @@
 
 package dan200.computercraft.shared.common;
 
-import dan200.computercraft.shared.container.BasicContainer;
-import dan200.computercraft.shared.util.BlockEntityHelpers;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
-import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.level.block.entity.BaseContainerBlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -17,7 +14,7 @@
 /**
  * A {@link BlockEntity} which exposes an inventory.
  */
-public abstract class AbstractContainerBlockEntity extends BaseContainerBlockEntity implements BasicContainer {
+public abstract class AbstractContainerBlockEntity extends BaseContainerBlockEntity {
     protected AbstractContainerBlockEntity(BlockEntityType<?> type, BlockPos pos, BlockState state) {
         super(type, pos, state);
     }
@@ -26,9 +23,4 @@ protected AbstractContainerBlockEntity(BlockEntityType<?> type, BlockPos pos, Bl
     protected final Component getDefaultName() {
         return Component.translatable(getBlockState().getBlock().getDescriptionId());
     }
-
-    @Override
-    public boolean stillValid(Player player) {
-        return BlockEntityHelpers.isUsable(this, player, BlockEntityHelpers.DEFAULT_INTERACT_RANGE);
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/common/ClearColourRecipe.java

@@ -4,9 +4,12 @@
 
 package dan200.computercraft.shared.common;
 
+import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.util.DataComponentUtil;
+import net.minecraft.core.HolderLookup;
 import net.minecraft.core.NonNullList;
-import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
@@ -16,7 +19,7 @@
 import net.minecraft.world.level.Level;
 
 /**
- * Craft a wet sponge with a {@linkplain IColouredItem dyable item} to remove its dye.
+ * Craft a wet sponge with a {@linkplain ComputerCraftTags.Items#DYEABLE dyable item} to remove its dye.
  */
 public final class ClearColourRecipe extends CustomRecipe {
     public ClearColourRecipe(CraftingBookCategory category) {
@@ -31,9 +34,9 @@ public boolean matches(CraftingContainer inv, Level world) {
             var stack = inv.getItem(i);
             if (stack.isEmpty()) continue;
 
-            if (stack.getItem() instanceof IColouredItem colourable) {
+            if (stack.is(ComputerCraftTags.Items.DYEABLE)) {
                 if (hasColourable) return false;
-                if (colourable.getColour(stack) == -1) return false;
+                if (!stack.has(DataComponents.DYED_COLOR)) return false;
                 hasColourable = true;
             } else if (stack.getItem() == Items.WET_SPONGE) {
                 if (hasSponge) return false;
@@ -47,19 +50,17 @@ public boolean matches(CraftingContainer inv, Level world) {
     }
 
     @Override
-    public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess) {
+    public ItemStack assemble(CraftingContainer inv, HolderLookup.Provider registryAccess) {
         var colourable = ItemStack.EMPTY;
 
         for (var i = 0; i < inv.getContainerSize(); i++) {
             var stack = inv.getItem(i);
-            if (stack.getItem() instanceof IColouredItem) colourable = stack;
+            if (stack.is(ComputerCraftTags.Items.DYEABLE)) colourable = stack;
         }
 
         if (colourable.isEmpty()) return ItemStack.EMPTY;
 
-        var stack = ((IColouredItem) colourable.getItem()).withColour(colourable, -1);
-        stack.setCount(1);
-        return stack;
+        return DataComponentUtil.createResult(colourable, DataComponents.DYED_COLOR, null);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/common/ColourableRecipe.java

@@ -4,12 +4,16 @@
 
 package dan200.computercraft.shared.common;
 
+import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.util.ColourTracker;
 import dan200.computercraft.shared.util.ColourUtils;
-import net.minecraft.core.RegistryAccess;
+import dan200.computercraft.shared.util.DataComponentUtil;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.item.crafting.CraftingBookCategory;
 import net.minecraft.world.item.crafting.CustomRecipe;
 import net.minecraft.world.item.crafting.RecipeSerializer;
@@ -28,7 +32,7 @@ public boolean matches(CraftingContainer inv, Level world) {
             var stack = inv.getItem(i);
             if (stack.isEmpty()) continue;
 
-            if (stack.getItem() instanceof IColouredItem) {
+            if (stack.is(ComputerCraftTags.Items.DYEABLE)) {
                 if (hasColourable) return false;
                 hasColourable = true;
             } else if (ColourUtils.getStackColour(stack) != null) {
@@ -42,7 +46,7 @@ public boolean matches(CraftingContainer inv, Level world) {
     }
 
     @Override
-    public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess) {
+    public ItemStack assemble(CraftingContainer inv, HolderLookup.Provider registryAccess) {
         var colourable = ItemStack.EMPTY;
 
         var tracker = new ColourTracker();
@@ -52,7 +56,7 @@ public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess)
 
             if (stack.isEmpty()) continue;
 
-            if (stack.getItem() instanceof IColouredItem) {
+            if (stack.is(ComputerCraftTags.Items.DYEABLE)) {
                 colourable = stack;
             } else {
                 var dye = ColourUtils.getStackColour(stack);
@@ -60,11 +64,10 @@ public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess)
             }
         }
 
-        if (colourable.isEmpty()) return ItemStack.EMPTY;
+        return colourable.isEmpty()
+            ? ItemStack.EMPTY
+            : DataComponentUtil.createResult(colourable, DataComponents.DYED_COLOR, new DyedItemColor(tracker.getColour(), false));
 
-        var stack = ((IColouredItem) colourable.getItem()).withColour(colourable, tracker.getColour());
-        stack.setCount(1);
-        return stack;
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/common/HorizontalContainerBlock.java

@@ -6,12 +6,9 @@
 
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.Containers;
-import net.minecraft.world.InteractionHand;
 import net.minecraft.world.InteractionResult;
-import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.AbstractContainerMenu;
-import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.context.BlockPlaceContext;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.BaseEntityBlock;
@@ -24,7 +21,6 @@
 import net.minecraft.world.level.block.state.properties.DirectionProperty;
 import net.minecraft.world.phys.BlockHitResult;
 
-import javax.annotation.Nullable;
 
 /**
  * A block which has a container and can be placed in a horizontal direction.
@@ -44,20 +40,17 @@ public final BlockState getStateForPlacement(BlockPlaceContext placement) {
     }
 
     @Override
-    @Deprecated
-    public final BlockState mirror(BlockState state, Mirror mirrorIn) {
+    protected final BlockState mirror(BlockState state, Mirror mirrorIn) {
         return state.rotate(mirrorIn.getRotation(state.getValue(FACING)));
     }
 
     @Override
-    @Deprecated
-    public final BlockState rotate(BlockState state, Rotation rot) {
+    protected final BlockState rotate(BlockState state, Rotation rot) {
         return state.setValue(FACING, rot.rotate(state.getValue(FACING)));
     }
 
     @Override
-    @Deprecated
-    public InteractionResult use(BlockState state, Level level, BlockPos pos, Player player, InteractionHand hand, BlockHitResult hit) {
+    protected InteractionResult useWithoutItem(BlockState state, Level level, BlockPos pos, Player player, BlockHitResult hit) {
         if (level.isClientSide) return InteractionResult.SUCCESS;
 
         if (level.getBlockEntity(pos) instanceof BaseContainerBlockEntity container) {
@@ -68,8 +61,7 @@ public InteractionResult use(BlockState state, Level level, BlockPos pos, Player
     }
 
     @Override
-    @Deprecated
-    public final void onRemove(BlockState state, Level level, BlockPos pos, BlockState newState, boolean isMoving) {
+    protected final void onRemove(BlockState state, Level level, BlockPos pos, BlockState newState, boolean isMoving) {
         if (state.is(newState.getBlock())) return;
 
         if (level.getBlockEntity(pos) instanceof BaseContainerBlockEntity container) {
@@ -81,27 +73,17 @@ public final void onRemove(BlockState state, Level level, BlockPos pos, BlockSta
     }
 
     @Override
-    public final void setPlacedBy(Level world, BlockPos pos, BlockState state, @Nullable LivingEntity placer, ItemStack stack) {
-        if (stack.hasCustomHoverName() && world.getBlockEntity(pos) instanceof BaseContainerBlockEntity container) {
-            container.setCustomName(stack.getHoverName());
-        }
-    }
-
-    @Override
-    @Deprecated
-    public final boolean hasAnalogOutputSignal(BlockState pState) {
+    protected final boolean hasAnalogOutputSignal(BlockState pState) {
         return true;
     }
 
     @Override
-    @Deprecated
-    public final int getAnalogOutputSignal(BlockState pBlockState, Level pLevel, BlockPos pPos) {
+    protected final int getAnalogOutputSignal(BlockState pBlockState, Level pLevel, BlockPos pPos) {
         return AbstractContainerMenu.getRedstoneSignalFromBlockEntity(pLevel.getBlockEntity(pPos));
     }
 
     @Override
-    @Deprecated
-    public RenderShape getRenderShape(BlockState state) {
+    protected RenderShape getRenderShape(BlockState state) {
         return RenderShape.MODEL;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/common/IColouredItem.java

@@ -1,35 +0,0 @@
-// SPDX-FileCopyrightText: 2017 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.common;
-
-import net.minecraft.world.item.ItemStack;
-
-public interface IColouredItem {
-    String NBT_COLOUR = "Color";
-
-    default int getColour(ItemStack stack) {
-        return getColourBasic(stack);
-    }
-
-    default ItemStack withColour(ItemStack stack, int colour) {
-        var copy = stack.copy();
-        setColourBasic(copy, colour);
-        return copy;
-    }
-
-    static int getColourBasic(ItemStack stack) {
-        var tag = stack.getTag();
-        return tag != null && tag.contains(NBT_COLOUR) ? tag.getInt(NBT_COLOUR) : -1;
-    }
-
-    static void setColourBasic(ItemStack stack, int colour) {
-        if (colour == -1) {
-            var tag = stack.getTag();
-            if (tag != null) tag.remove(NBT_COLOUR);
-        } else {
-            stack.getOrCreateTag().putInt(NBT_COLOUR, colour);
-        }
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/computer/apis/CommandAPI.java

@@ -78,7 +78,7 @@ private static final class CommandState {
         var table = VanillaDetailRegistries.BLOCK_IN_WORLD.getDetails(block);
 
         var tile = block.blockEntity();
-        if (tile != null) table.put("nbt", NBTUtil.toLua(tile.saveWithFullMetadata()));
+        if (tile != null) table.put("nbt", NBTUtil.toLua(tile.saveWithFullMetadata(world.registryAccess())));
 
         return table;
     }

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlock.java

@@ -7,7 +7,7 @@
 import dan200.computercraft.annotations.ForgeOverride;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.shared.common.IBundledRedstoneBlock;
-import dan200.computercraft.shared.computer.items.IComputerItem;
+import dan200.computercraft.shared.network.container.ComputerContainerData;
 import dan200.computercraft.shared.platform.RegistryEntry;
 import dan200.computercraft.shared.util.BlockEntityHelpers;
 import net.minecraft.core.BlockPos;
@@ -15,10 +15,8 @@
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.stats.Stats;
-import net.minecraft.world.InteractionHand;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.MenuProvider;
-import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.BlockGetter;
@@ -51,8 +49,7 @@ protected AbstractComputerBlock(Properties settings, RegistryEntry<BlockEntityTy
     }
 
     @Override
-    @Deprecated
-    public void onPlace(BlockState state, Level world, BlockPos pos, BlockState oldState, boolean isMoving) {
+    protected void onPlace(BlockState state, Level world, BlockPos pos, BlockState oldState, boolean isMoving) {
         super.onPlace(state, world, pos, oldState, isMoving);
 
         var tile = world.getBlockEntity(pos);
@@ -60,14 +57,12 @@ public void onPlace(BlockState state, Level world, BlockPos pos, BlockState oldS
     }
 
     @Override
-    @Deprecated
-    public boolean isSignalSource(BlockState state) {
+    protected boolean isSignalSource(BlockState state) {
         return true;
     }
 
     @Override
-    @Deprecated
-    public int getDirectSignal(BlockState state, BlockGetter world, BlockPos pos, Direction incomingSide) {
+    protected int getDirectSignal(BlockState state, BlockGetter world, BlockPos pos, Direction incomingSide) {
         var entity = world.getBlockEntity(pos);
         if (!(entity instanceof AbstractComputerBlockEntity computerEntity)) return 0;
 
@@ -78,11 +73,14 @@ public int getDirectSignal(BlockState state, BlockGetter world, BlockPos pos, Di
         return computer.getRedstoneOutput(localSide);
     }
 
-    protected abstract ItemStack getItem(AbstractComputerBlockEntity tile);
+    protected final ItemStack getItem(AbstractComputerBlockEntity tile) {
+        var stack = new ItemStack(this);
+        stack.applyComponents(tile.collectComponents());
+        return stack;
+    }
 
     @Override
-    @Deprecated
-    public int getSignal(BlockState state, BlockGetter world, BlockPos pos, Direction incomingSide) {
+    protected int getSignal(BlockState state, BlockGetter world, BlockPos pos, Direction incomingSide) {
         return getDirectSignal(state, world, pos, incomingSide);
     }
 
@@ -99,7 +97,6 @@ public int getBundledRedstoneOutput(Level world, BlockPos pos, Direction side) {
     }
 
     @Override
-    @Deprecated
     public ItemStack getCloneItemStack(LevelReader world, BlockPos pos, BlockState state) {
         var tile = world.getBlockEntity(pos);
         if (tile instanceof AbstractComputerBlockEntity computer) {
@@ -144,29 +141,23 @@ public BlockState playerWillDestroy(Level world, BlockPos pos, BlockState state,
     }
 
     @Override
-    public void setPlacedBy(Level world, BlockPos pos, BlockState state, @Nullable LivingEntity placer, ItemStack stack) {
-        super.setPlacedBy(world, pos, state, placer, stack);
+    protected InteractionResult useWithoutItem(BlockState state, Level level, BlockPos pos, Player player, BlockHitResult hit) {
+        if (!player.isCrouching() && level.getBlockEntity(pos) instanceof AbstractComputerBlockEntity computer) {
+            // Regular right click to activate computer
+            if (!level.isClientSide && computer.isUsable(player)) {
+                var serverComputer = computer.createServerComputer();
+                serverComputer.turnOn();
 
-        var tile = world.getBlockEntity(pos);
-        if (!world.isClientSide && tile instanceof IComputerBlockEntity computer && stack.getItem() instanceof IComputerItem item) {
-
-            var id = item.getComputerID(stack);
-            if (id != -1) computer.setComputerID(id);
-
-            var label = item.getLabel(stack);
-            if (label != null) computer.setLabel(label);
+                new ComputerContainerData(serverComputer, getItem(computer)).open(player, computer);
+            }
+            return InteractionResult.sidedSuccess(level.isClientSide);
         }
+
+        return super.useWithoutItem(state, level, pos, player, hit);
     }
 
     @Override
-    @Deprecated
-    public final InteractionResult use(BlockState state, Level world, BlockPos pos, Player player, InteractionHand hand, BlockHitResult hit) {
-        return world.getBlockEntity(pos) instanceof AbstractComputerBlockEntity computer ? computer.use(player, hand) : InteractionResult.PASS;
-    }
-
-    @Override
-    @Deprecated
-    public final void neighborChanged(BlockState state, Level world, BlockPos pos, Block neighbourBlock, BlockPos neighbourPos, boolean isMoving) {
+    protected final void neighborChanged(BlockState state, Level world, BlockPos pos, Block neighbourBlock, BlockPos neighbourPos, boolean isMoving) {
         var be = world.getBlockEntity(pos);
         if (be instanceof AbstractComputerBlockEntity computer) computer.neighborChanged(neighbourPos);
     }
@@ -178,8 +169,7 @@ public final void onNeighborChange(BlockState state, LevelReader world, BlockPos
     }
 
     @Override
-    @Deprecated
-    public BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor level, BlockPos pos, BlockPos neighborPos) {
+    protected BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor level, BlockPos pos, BlockPos neighborPos) {
         var be = level.getBlockEntity(pos);
         if (be instanceof AbstractComputerBlockEntity computer) computer.neighbourShapeChanged(direction);
 
@@ -188,8 +178,7 @@ public BlockState updateShape(BlockState state, Direction direction, BlockState
 
     @Nullable
     @Override
-    @Deprecated
-    public MenuProvider getMenuProvider(BlockState state, Level level, BlockPos pos) {
+    protected MenuProvider getMenuProvider(BlockState state, Level level, BlockPos pos) {
         return level.getBlockEntity(pos) instanceof AbstractComputerBlockEntity computer ? computer : null;
     }
 

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlockEntity.java

@@ -9,26 +9,28 @@
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.impl.BundledRedstone;
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.core.ServerContext;
-import dan200.computercraft.shared.network.container.ComputerContainerData;
+import dan200.computercraft.shared.computer.items.ComputerId;
 import dan200.computercraft.shared.platform.ComponentAccess;
 import dan200.computercraft.shared.platform.PlatformHelper;
-import dan200.computercraft.shared.util.BlockEntityHelpers;
-import dan200.computercraft.shared.util.DirectionUtil;
-import dan200.computercraft.shared.util.IDAssigner;
-import dan200.computercraft.shared.util.RedstoneUtil;
+import dan200.computercraft.shared.util.*;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponentMap;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
-import net.minecraft.world.*;
+import net.minecraft.world.Container;
+import net.minecraft.world.LockCode;
+import net.minecraft.world.MenuProvider;
+import net.minecraft.world.Nameable;
 import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
 import net.minecraft.world.level.block.entity.BaseContainerBlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -76,42 +78,13 @@ public void setRemoved() {
         unload();
     }
 
-    protected boolean canNameWithTag(Player player) {
-        return false;
-    }
-
-    protected double getInteractRange() {
-        return BlockEntityHelpers.DEFAULT_INTERACT_RANGE;
+    protected float getInteractRange() {
+        return Container.DEFAULT_DISTANCE_BUFFER;
     }
 
     public boolean isUsable(Player player) {
         return BaseContainerBlockEntity.canUnlock(player, lockCode, getDisplayName())
-            && BlockEntityHelpers.isUsable(this, player, getInteractRange());
-    }
-
-    public InteractionResult use(Player player, InteractionHand hand) {
-        var currentItem = player.getItemInHand(hand);
-        if (!currentItem.isEmpty() && currentItem.getItem() == Items.NAME_TAG && canNameWithTag(player) && currentItem.hasCustomHoverName()) {
-            // Label to rename computer
-            if (!getLevel().isClientSide) {
-                setLabel(currentItem.getHoverName().getString());
-                currentItem.shrink(1);
-            }
-            return InteractionResult.sidedSuccess(getLevel().isClientSide);
-        } else if (!player.isCrouching()) {
-            // Regular right click to activate computer
-            if (!getLevel().isClientSide && isUsable(player)) {
-                var computer = createServerComputer();
-                computer.turnOn();
-
-                var stack = getBlockState().getBlock() instanceof AbstractComputerBlock<?>
-                    ? ((AbstractComputerBlock<?>) getBlockState().getBlock()).getItem(this)
-                    : ItemStack.EMPTY;
-                new ComputerContainerData(computer, stack).open(player, this);
-            }
-            return InteractionResult.sidedSuccess(getLevel().isClientSide);
-        }
-        return InteractionResult.PASS;
+            && Container.stillValidBlockEntity(this, player, getInteractRange());
     }
 
     protected void serverTick() {
@@ -166,7 +139,7 @@ protected void serverTick() {
     protected abstract void updateBlockState(ComputerState newState);
 
     @Override
-    public void saveAdditional(CompoundTag nbt) {
+    public void saveAdditional(CompoundTag nbt, HolderLookup.Provider registries) {
         // Save ID, label and power state
         if (computerID >= 0) nbt.putInt(NBT_ID, computerID);
         if (label != null) nbt.putString(NBT_LABEL, label);
@@ -174,20 +147,20 @@ public void saveAdditional(CompoundTag nbt) {
 
         lockCode.addToTag(nbt);
 
-        super.saveAdditional(nbt);
+        super.saveAdditional(nbt, registries);
     }
 
     @Override
-    public final void load(CompoundTag nbt) {
-        super.load(nbt);
+    public final void loadAdditional(CompoundTag nbt, HolderLookup.Provider registries) {
+        super.loadAdditional(nbt, registries);
         if (level != null && level.isClientSide) {
-            loadClient(nbt);
+            loadClient(nbt, registries);
         } else {
-            loadServer(nbt);
+            loadServer(nbt, registries);
         }
     }
 
-    protected void loadServer(CompoundTag nbt) {
+    protected void loadServer(CompoundTag nbt, HolderLookup.Provider registries) {
         // Load ID, label and power state
         computerID = nbt.contains(NBT_ID) ? nbt.getInt(NBT_ID) : -1;
         label = nbt.contains(NBT_LABEL) ? nbt.getString(NBT_LABEL) : null;
@@ -196,6 +169,31 @@ protected void loadServer(CompoundTag nbt) {
         lockCode = LockCode.fromTag(nbt);
     }
 
+    @Override
+    protected void applyImplicitComponents(DataComponentInput component) {
+        super.applyImplicitComponents(component);
+        label = DataComponentUtil.getCustomName(component.get(DataComponents.CUSTOM_NAME));
+        computerID = ComputerId.getId(component.get(ModRegistry.DataComponents.COMPUTER_ID.get()));
+        lockCode = component.getOrDefault(DataComponents.LOCK, LockCode.NO_LOCK);
+    }
+
+    @Override
+    protected void collectImplicitComponents(DataComponentMap.Builder builder) {
+        super.collectImplicitComponents(builder);
+        builder.set(ModRegistry.DataComponents.COMPUTER_ID.get(), ComputerId.of(computerID));
+        builder.set(DataComponents.CUSTOM_NAME, label == null ? null : Component.literal(label));
+        if (lockCode != LockCode.NO_LOCK) builder.set(DataComponents.LOCK, lockCode);
+    }
+
+    @Override
+    @Deprecated
+    public void removeComponentsFromTag(CompoundTag tag) {
+        super.removeComponentsFromTag(tag);
+        tag.remove(NBT_ID);
+        tag.remove(NBT_LABEL);
+        tag.remove(LockCode.TAG_LOCK);
+    }
+
     protected boolean isPeripheralBlockedOnSide(ComputerSide localSide) {
         return false;
     }
@@ -343,7 +341,7 @@ public final void setComputerID(int id) {
         if (getLevel().isClientSide || computerID == id) return;
 
         computerID = id;
-        setChanged();
+        BlockEntityHelpers.updateBlock(this);
     }
 
     @Override
@@ -353,7 +351,7 @@ public final void setLabel(@Nullable String label) {
         this.label = label;
         var computer = getServerComputer();
         if (computer != null) computer.setLabel(label);
-        setChanged();
+        BlockEntityHelpers.updateBlock(this);
     }
 
     @Override
@@ -399,15 +397,15 @@ public final ClientboundBlockEntityDataPacket getUpdatePacket() {
     }
 
     @Override
-    public CompoundTag getUpdateTag() {
+    public CompoundTag getUpdateTag(HolderLookup.Provider registries) {
         // We need this for pick block on the client side.
-        var nbt = super.getUpdateTag();
+        var nbt = super.getUpdateTag(registries);
         if (label != null) nbt.putString(NBT_LABEL, label);
         if (computerID >= 0) nbt.putInt(NBT_ID, computerID);
         return nbt;
     }
 
-    protected void loadClient(CompoundTag nbt) {
+    protected void loadClient(CompoundTag nbt, HolderLookup.Provider registries) {
         label = nbt.contains(NBT_LABEL) ? nbt.getString(NBT_LABEL) : null;
         computerID = nbt.contains(NBT_ID) ? nbt.getInt(NBT_ID) : -1;
     }

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/ComputerBlock.java

@@ -7,11 +7,9 @@
 import com.mojang.serialization.MapCodec;
 import com.mojang.serialization.codecs.RecordCodecBuilder;
 import dan200.computercraft.shared.computer.core.ComputerState;
-import dan200.computercraft.shared.computer.items.ComputerItem;
 import dan200.computercraft.shared.platform.RegistryEntry;
 import dan200.computercraft.shared.util.BlockCodecs;
 import net.minecraft.core.Direction;
-import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.context.BlockPlaceContext;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -55,12 +53,4 @@ protected MapCodec<? extends ComputerBlock<?>> codec() {
     public BlockState getStateForPlacement(BlockPlaceContext placement) {
         return defaultBlockState().setValue(FACING, placement.getHorizontalDirection().getOpposite());
     }
-
-    @Override
-    protected ItemStack getItem(AbstractComputerBlockEntity tile) {
-        if (!(tile instanceof ComputerBlockEntity computer)) return ItemStack.EMPTY;
-        if (!(asItem() instanceof ComputerItem item)) return ItemStack.EMPTY;
-
-        return item.create(computer.getComputerID(), computer.getLabel());
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/items/AbstractComputerItem.java

@@ -7,30 +7,32 @@
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.media.IMedia;
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.computer.blocks.AbstractComputerBlock;
 import dan200.computercraft.shared.config.Config;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import net.minecraft.ChatFormatting;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.item.BlockItem;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.TooltipFlag;
-import net.minecraft.world.level.Level;
 
 import javax.annotation.Nullable;
 import java.util.List;
 
-public abstract class AbstractComputerItem extends BlockItem implements IComputerItem, IMedia {
+public class AbstractComputerItem extends BlockItem implements IMedia {
     public AbstractComputerItem(AbstractComputerBlock<?> block, Properties settings) {
         super(block, settings);
     }
 
     @Override
-    public void appendHoverText(ItemStack stack, @Nullable Level world, List<Component> list, TooltipFlag options) {
-        if (options.isAdvanced() || getLabel(stack) == null) {
-            var id = getComputerID(stack);
-            if (id >= 0) {
-                list.add(Component.translatable("gui.computercraft.tooltip.computer_id", id)
+    public void appendHoverText(ItemStack stack, TooltipContext context, List<Component> list, TooltipFlag options) {
+        if (options.isAdvanced() || !stack.has(DataComponents.CUSTOM_NAME)) {
+            var id = stack.get(ModRegistry.DataComponents.COMPUTER_ID.get());
+            if (id != null) {
+                list.add(Component.translatable("gui.computercraft.tooltip.computer_id", id.id())
                     .withStyle(ChatFormatting.GRAY));
             }
         }
@@ -38,22 +40,18 @@ public void appendHoverText(ItemStack stack, @Nullable Level world, List<Compone
 
     @Override
     public @Nullable String getLabel(ItemStack stack) {
-        return IComputerItem.super.getLabel(stack);
+        return DataComponentUtil.getCustomName(stack);
     }
 
     @Override
     public boolean setLabel(ItemStack stack, @Nullable String label) {
-        if (label != null) {
-            stack.setHoverName(Component.literal(label));
-        } else {
-            stack.resetHoverName();
-        }
+        DataComponentUtil.setCustomName(stack, label);
         return true;
     }
 
     @Override
     public @Nullable Mount createDataMount(ItemStack stack, ServerLevel level) {
-        var id = getComputerID(stack);
-        return id >= 0 ? ComputerCraftAPI.createSaveDirMount(level.getServer(), "computer/" + id, Config.computerSpaceLimit) : null;
+        var id = stack.get(ModRegistry.DataComponents.COMPUTER_ID.get());
+        return id != null ? ComputerCraftAPI.createSaveDirMount(level.getServer(), "computer/" + id.id(), Config.computerSpaceLimit) : null;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ComputerId.java

@@ -0,0 +1,40 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.computer.items;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import dan200.computercraft.shared.ModRegistry;
+import io.netty.buffer.ByteBuf;
+import net.minecraft.core.component.DataComponentHolder;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+
+import javax.annotation.Nullable;
+
+public record ComputerId(int id) {
+    public static final Codec<ComputerId> CODEC = Codec.INT.flatXmap(
+        x -> x < 0 ? DataResult.error(() -> "Disk ID must be >= 0") : DataResult.success(new ComputerId(x)),
+        x -> DataResult.success(x.id())
+    );
+
+    public static final StreamCodec<ByteBuf, ComputerId> STREAM_CODEC = ByteBufCodecs.INT.map(ComputerId::new, ComputerId::id);
+
+    public ComputerId {
+        if (id < 0) throw new IllegalArgumentException("Computer id cannot be < 0");
+    }
+
+    public static int getId(DataComponentHolder holder) {
+        return getId(holder.get(ModRegistry.DataComponents.COMPUTER_ID.get()));
+    }
+
+    public static int getId(@Nullable ComputerId id) {
+        return id == null ? -1 : id.id();
+    }
+
+    public static @Nullable ComputerId of(int id) {
+        return id >= 0 ? new ComputerId(id) : null;
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ComputerItem.java

@@ -5,28 +5,10 @@
 package dan200.computercraft.shared.computer.items;
 
 import dan200.computercraft.shared.computer.blocks.ComputerBlock;
-import net.minecraft.network.chat.Component;
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.ItemStack;
-
-import javax.annotation.Nullable;
 
 public class ComputerItem extends AbstractComputerItem {
+    // TODO: Do we deprecate this?
     public ComputerItem(ComputerBlock<?> block, Properties settings) {
         super(block, settings);
     }
-
-    public ItemStack create(int id, @Nullable String label) {
-        var result = new ItemStack(this);
-        if (id >= 0) result.getOrCreateTag().putInt(NBT_ID, id);
-        if (label != null) result.setHoverName(Component.literal(label));
-        return result;
-    }
-
-    @Override
-    public ItemStack changeItem(ItemStack stack, Item newItem) {
-        return newItem instanceof ComputerItem computer
-            ? computer.create(getComputerID(stack), getLabel(stack))
-            : ItemStack.EMPTY;
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/items/IComputerItem.java

@@ -1,35 +0,0 @@
-// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
-//
-// SPDX-License-Identifier: LicenseRef-CCPL
-
-package dan200.computercraft.shared.computer.items;
-
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.ItemStack;
-
-import javax.annotation.Nullable;
-
-public interface IComputerItem {
-    String NBT_ID = "ComputerId";
-
-    default int getComputerID(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_ID) ? nbt.getInt(NBT_ID) : -1;
-    }
-
-    default @Nullable String getLabel(ItemStack stack) {
-        return stack.hasCustomHoverName() ? stack.getHoverName().getString() : null;
-    }
-
-    /**
-     * Create a new stack, changing the underlying item.
-     * <p>
-     * This should copy the computer's data to a different item of the same type (for instance, converting a normal
-     * computer to an advanced one).
-     *
-     * @param stack   The current computer stack.
-     * @param newItem The new item.
-     * @return The new stack, possibly {@linkplain ItemStack#EMPTY empty} if {@code newItem} is of the same type.
-     */
-    ItemStack changeItem(ItemStack stack, Item newItem);
-}

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ServerComputerReference.java

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.computer.items;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.computer.core.ServerComputer;
+import dan200.computercraft.shared.computer.core.ServerComputerRegistry;
+import net.minecraft.core.UUIDUtil;
+import net.minecraft.core.component.DataComponentHolder;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+
+import javax.annotation.Nullable;
+import java.util.UUID;
+
+/**
+ * A reference to a {@link ServerComputer}.
+ *
+ * @param session  The current {@linkplain ServerComputerRegistry#getSessionID() session id}.
+ * @param instance The computer's {@linkplain ServerComputer#getInstanceUUID() instance id}.
+ */
+public record ServerComputerReference(int session, UUID instance) {
+    public static final Codec<ServerComputerReference> CODEC = RecordCodecBuilder.create(i -> i.group(
+        Codec.INT.fieldOf("session").forGetter(ServerComputerReference::session),
+        UUIDUtil.CODEC.fieldOf("session").forGetter(ServerComputerReference::instance)
+    ).apply(i, ServerComputerReference::new));
+
+    public static final StreamCodec<RegistryFriendlyByteBuf, ServerComputerReference> STREAM_CODEC = StreamCodec.composite(
+        ByteBufCodecs.VAR_INT, ServerComputerReference::session,
+        UUIDUtil.STREAM_CODEC, ServerComputerReference::instance,
+        ServerComputerReference::new
+    );
+
+    public @Nullable ServerComputer get(ServerComputerRegistry registry) {
+        return registry.get(session, this.instance());
+    }
+
+    public static @Nullable ServerComputer get(DataComponentHolder holder, ServerComputerRegistry registry) {
+        var reference = holder.get(ModRegistry.DataComponents.COMPUTER.get());
+        return reference == null ? null : reference.get(registry);
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerConvertRecipe.java

@@ -4,43 +4,50 @@
 
 package dan200.computercraft.shared.computer.recipe;
 
-import dan200.computercraft.shared.computer.items.IComputerItem;
+import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.computer.items.AbstractComputerItem;
+import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.recipe.CustomShapedRecipe;
 import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
-import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.HolderLookup;
 import net.minecraft.world.inventory.CraftingContainer;
+import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.level.Level;
+import net.minecraft.world.item.crafting.RecipeSerializer;
 
 /**
  * A recipe which converts a computer from one form into another.
  */
-public abstract class ComputerConvertRecipe extends CustomShapedRecipe {
+public final class ComputerConvertRecipe extends CustomShapedRecipe {
+    private final Item result;
+
     public ComputerConvertRecipe(ShapedRecipeSpec recipe) {
         super(recipe);
-    }
-
-    protected abstract ItemStack convert(IComputerItem item, ItemStack stack);
-
-    @Override
-    public boolean matches(CraftingContainer inventory, Level world) {
-        if (!super.matches(inventory, world)) return false;
-
-        for (var i = 0; i < inventory.getContainerSize(); i++) {
-            if (inventory.getItem(i).getItem() instanceof IComputerItem) return true;
-        }
-
-        return false;
+        this.result = recipe.result().getItem();
     }
 
     @Override
-    public ItemStack assemble(CraftingContainer inventory, RegistryAccess registryAccess) {
-        // Find our computer item and convert it.
+    public ItemStack assemble(CraftingContainer inventory, HolderLookup.Provider registryAccess) {
+        // Find our computer item and copy the components across.
         for (var i = 0; i < inventory.getContainerSize(); i++) {
             var stack = inventory.getItem(i);
-            if (stack.getItem() instanceof IComputerItem) return convert((IComputerItem) stack.getItem(), stack);
+            if (isComputerItem(stack.getItem())) {
+                var newStack = new ItemStack(result);
+                newStack.applyComponents(stack.getComponentsPatch());
+                return newStack;
+            }
         }
 
         return ItemStack.EMPTY;
     }
+
+    @Override
+    public RecipeSerializer<ComputerConvertRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.COMPUTER_CONVERT.get();
+    }
+
+    private static boolean isComputerItem(Item item) {
+        // TODO: Make this a little more general. Either with a tag, or a predicate on the recipe itself?
+        return item instanceof AbstractComputerItem || item instanceof PocketComputerItem;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerUpgradeRecipe.java

@@ -1,46 +0,0 @@
-// SPDX-FileCopyrightText: 2019 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.computer.recipe;
-
-import com.mojang.serialization.DataResult;
-import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.items.IComputerItem;
-import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.RecipeSerializer;
-
-/**
- * A recipe which "upgrades" a {@linkplain IComputerItem computer}, converting to it a new item (for instance a normal
- * turtle to an advanced one).
- *
- * @see IComputerItem#changeItem(ItemStack, Item)
- */
-public final class ComputerUpgradeRecipe extends ComputerConvertRecipe {
-    private final Item result;
-
-    public ComputerUpgradeRecipe(ShapedRecipeSpec recipe) {
-        super(recipe);
-        this.result = recipe.result().getItem();
-    }
-
-    public static DataResult<ComputerUpgradeRecipe> of(ShapedRecipeSpec recipe) {
-        if (!(recipe.result().getItem() instanceof IComputerItem)) {
-            return DataResult.error(() -> recipe.result().getItem() + " is not a computer item");
-        }
-
-        return DataResult.success(new ComputerUpgradeRecipe(recipe));
-    }
-
-    @Override
-    protected ItemStack convert(IComputerItem item, ItemStack stack) {
-        return item.changeItem(stack, result);
-    }
-
-    @Override
-    public RecipeSerializer<ComputerUpgradeRecipe> getSerializer() {
-        return ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get();
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/computer/terminal/TerminalState.java

@@ -7,6 +7,7 @@
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
 
 import javax.annotation.Nullable;
 
@@ -18,6 +19,8 @@
  * states, etc...
  */
 public class TerminalState {
+    public static final StreamCodec<FriendlyByteBuf, TerminalState> STREAM_CODEC = StreamCodec.ofMember(TerminalState::write, TerminalState::new);
+
     private final boolean colour;
     private final int width;
     private final int height;
@@ -27,6 +30,7 @@ public class TerminalState {
 
     public TerminalState(@Nullable NetworkedTerminal terminal) {
         if (terminal == null) {
+            // TODO: Make this non-nullable, and have an Optional<...> codec.
             colour = false;
             width = height = 0;
             buffer = null;
@@ -40,7 +44,7 @@ public TerminalState(@Nullable NetworkedTerminal terminal) {
         }
     }
 
-    public TerminalState(FriendlyByteBuf buf) {
+    private TerminalState(FriendlyByteBuf buf) {
         colour = buf.readBoolean();
 
         if (buf.readBoolean()) {
@@ -55,7 +59,7 @@ public TerminalState(FriendlyByteBuf buf) {
         }
     }
 
-    public void write(FriendlyByteBuf buf) {
+    private void write(FriendlyByteBuf buf) {
         buf.writeBoolean(colour);
 
         buf.writeBoolean(buffer != null);

projects/common/src/main/java/dan200/computercraft/shared/container/BasicContainer.java

@@ -10,19 +10,19 @@
 import net.minecraft.world.item.ItemStack;
 
 /**
- * A basic implementation of {@link Container} which operates on a {@linkplain #getContents() list of stacks}.
+ * A basic implementation of {@link Container} which operates on a {@linkplain #getItems() list of stacks}.
  */
 public interface BasicContainer extends Container {
-    NonNullList<ItemStack> getContents();
+    NonNullList<ItemStack> getItems();
 
     @Override
     default int getContainerSize() {
-        return getContents().size();
+        return getItems().size();
     }
 
     @Override
     default boolean isEmpty() {
-        for (var stack : getContents()) {
+        for (var stack : getItems()) {
             if (!stack.isEmpty()) return false;
         }
 
@@ -31,27 +31,33 @@ default boolean isEmpty() {
 
     @Override
     default ItemStack getItem(int slot) {
-        var contents = getContents();
+        var contents = getItems();
         return slot >= 0 && slot < contents.size() ? contents.get(slot) : ItemStack.EMPTY;
     }
 
     @Override
     default ItemStack removeItemNoUpdate(int slot) {
-        return ContainerHelper.takeItem(getContents(), slot);
+        return ContainerHelper.takeItem(getItems(), slot);
     }
 
     @Override
     default ItemStack removeItem(int slot, int count) {
-        return ContainerHelper.removeItem(getContents(), slot, count);
+        return ContainerHelper.removeItem(getItems(), slot, count);
     }
 
     @Override
     default void setItem(int slot, ItemStack itemStack) {
-        getContents().set(slot, itemStack);
+        getItems().set(slot, itemStack);
     }
 
     @Override
     default void clearContent() {
-        getContents().clear();
+        getItems().clear();
+    }
+
+    static void defaultSetItems(NonNullList<ItemStack> inventory, NonNullList<ItemStack> items) {
+        var i = 0;
+        for (; i < items.size(); i++) inventory.set(i, items.get(i));
+        for (; i < inventory.size(); i++) inventory.set(i, ItemStack.EMPTY);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/container/BasicWorldlyContainer.java

@@ -11,7 +11,7 @@
 import javax.annotation.Nullable;
 
 /**
- * A basic implementation of {@link WorldlyContainer} which operates on a {@linkplain #getContents() list of stacks}.
+ * A basic implementation of {@link WorldlyContainer} which operates on a {@linkplain #getItems() list of stacks}.
  */
 public interface BasicWorldlyContainer extends BasicContainer, WorldlyContainer {
     @Override

projects/common/src/main/java/dan200/computercraft/shared/details/ItemDetails.java

@@ -4,20 +4,23 @@
 
 package dan200.computercraft.shared.details;
 
-import com.google.gson.JsonParseException;
 import dan200.computercraft.shared.util.NBTUtil;
+import net.minecraft.core.component.DataComponentPatch;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.BuiltInRegistries;
-import net.minecraft.nbt.ListTag;
-import net.minecraft.nbt.Tag;
+import net.minecraft.nbt.NbtOps;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.item.CreativeModeTab;
 import net.minecraft.world.item.CreativeModeTabs;
-import net.minecraft.world.item.EnchantedBookItem;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.enchantment.EnchantmentHelper;
+import net.minecraft.world.item.enchantment.ItemEnchantments;
 
 import javax.annotation.Nullable;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
 /**
  * Data providers for items.
@@ -26,7 +29,9 @@ public class ItemDetails {
     public static void fillBasic(Map<? super String, Object> data, ItemStack stack) {
         data.put("name", DetailHelpers.getId(BuiltInRegistries.ITEM, stack.getItem()));
         data.put("count", stack.getCount());
-        var hash = NBTUtil.getNBTHash(stack.getTag());
+
+        var components = stack.getComponentsPatch();
+        var hash = components.isEmpty() ? null : NBTUtil.getNBTHash(DataComponentPatch.CODEC.encodeStart(NbtOps.INSTANCE, components).result().orElse(null));
         if (hash != null) data.put("nbt", hash);
     }
 
@@ -46,41 +51,14 @@ public static void fill(Map<? super String, Object> data, ItemStack stack) {
         data.put("tags", DetailHelpers.getTags(stack.getTags()));
         data.put("itemGroups", getItemGroups(stack));
 
-        var tag = stack.getTag();
-        if (tag != null && tag.contains("display", Tag.TAG_COMPOUND)) {
-            var displayTag = tag.getCompound("display");
-            if (displayTag.contains("Lore", Tag.TAG_LIST)) {
-                var loreTag = displayTag.getList("Lore", Tag.TAG_STRING);
-                data.put("lore", loreTag.stream()
-                    .map(ItemDetails::parseTextComponent)
-                    .filter(Objects::nonNull)
-                    .map(Component::getString)
-                    .toList());
-            }
-        }
+        var lore = stack.get(DataComponents.LORE);
+        if (lore != null) data.put("lore", lore.lines().stream().map(Component::getString).toList());
 
-        /*
-         * Used to hide some data from ItemStack tooltip.
-         * @see https://minecraft.wiki/w/Tutorials/Command_NBT_tags
-         * @see ItemStack#getTooltip
-         */
-        var hideFlags = tag != null ? tag.getInt("HideFlags") : 0;
-
-        var enchants = getAllEnchants(stack, hideFlags);
+        var enchants = getAllEnchants(stack);
         if (!enchants.isEmpty()) data.put("enchantments", enchants);
 
-        if (tag != null && tag.getBoolean("Unbreakable") && (hideFlags & 4) == 0) {
-            data.put("unbreakable", true);
-        }
-    }
-
-    @Nullable
-    private static Component parseTextComponent(Tag x) {
-        try {
-            return Component.Serializer.fromJson(x.getAsString());
-        } catch (JsonParseException e) {
-            return null;
-        }
+        var unbreakable = stack.get(DataComponents.UNBREAKABLE);
+        if (unbreakable != null && unbreakable.showInTooltip()) data.put("unbreakable", true);
     }
 
     /**
@@ -107,26 +85,13 @@ private static List<Map<String, Object>> getItemGroups(ItemStack stack) {
     /**
      * Retrieve all visible enchantments from given stack. Try to follow all tooltip rules : order and visibility.
      *
-     * @param stack     Stack to analyse
-     * @param hideFlags An int used as bit field to provide visibility rules.
+     * @param stack Stack to analyse
      * @return A filled list that contain all visible enchantments.
      */
-    private static List<Map<String, Object>> getAllEnchants(ItemStack stack, int hideFlags) {
+    private static List<Map<String, Object>> getAllEnchants(ItemStack stack) {
         var enchants = new ArrayList<Map<String, Object>>(0);
-
-        if (stack.getItem() instanceof EnchantedBookItem && (hideFlags & 32) == 0) {
-            addEnchantments(EnchantedBookItem.getEnchantments(stack), enchants);
-        }
-
-        if (stack.isEnchanted() && (hideFlags & 1) == 0) {
-            /*
-             * Mimic the EnchantmentHelper.getEnchantments(ItemStack stack) behavior without special case for Enchanted book.
-             * I'll do that to have the same data than ones displayed in tooltip.
-             * @see EnchantmentHelper.getEnchantments(ItemStack stack)
-             */
-            addEnchantments(stack.getEnchantmentTags(), enchants);
-        }
-
+        addEnchantments(stack.get(DataComponents.STORED_ENCHANTMENTS), enchants);
+        addEnchantments(stack.get(DataComponents.ENCHANTMENTS), enchants);
         return enchants;
     }
 
@@ -138,18 +103,18 @@ private static List<Map<String, Object>> getAllEnchants(ItemStack stack, int hid
      * @see EnchantmentHelper
      */
     @SuppressWarnings("NonApiType")
-    private static void addEnchantments(ListTag rawEnchants, ArrayList<Map<String, Object>> enchants) {
-        if (rawEnchants.isEmpty()) return;
+    private static void addEnchantments(@Nullable ItemEnchantments rawEnchants, ArrayList<Map<String, Object>> enchants) {
+        if (rawEnchants == null || rawEnchants.isEmpty()) return;
 
         enchants.ensureCapacity(enchants.size() + rawEnchants.size());
 
-        for (var entry : EnchantmentHelper.deserializeEnchantments(rawEnchants).entrySet()) {
+        for (var entry : rawEnchants.entrySet()) {
             var enchantment = entry.getKey();
-            var level = entry.getValue();
+            var level = entry.getIntValue();
             var enchant = new HashMap<String, Object>(3);
-            enchant.put("name", DetailHelpers.getId(BuiltInRegistries.ENCHANTMENT, enchantment));
+            enchant.put("name", DetailHelpers.getId(BuiltInRegistries.ENCHANTMENT, enchantment.value()));
             enchant.put("level", level);
-            enchant.put("displayName", enchantment.getFullname(level).getString());
+            enchant.put("displayName", enchantment.value().getFullname(level).getString());
             enchants.add(enchant);
         }
     }

projects/common/src/main/java/dan200/computercraft/shared/integration/RecipeModHelpers.java

@@ -11,6 +11,7 @@
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 
@@ -54,14 +55,14 @@ public static List<ItemStack> getExtraStacks() {
         for (var turtleSupplier : TURTLES) {
             var turtle = turtleSupplier.get();
             for (var upgrade : TurtleUpgrades.instance().getUpgrades()) {
-                upgradeItems.add(turtle.create(-1, null, -1, null, UpgradeData.ofDefault(upgrade), 0, null));
+                upgradeItems.add(DataComponentUtil.createStack(turtle, ModRegistry.DataComponents.RIGHT_TURTLE_UPGRADE.get(), UpgradeData.ofDefault(upgrade)));
             }
         }
 
         for (var pocketSupplier : POCKET_COMPUTERS) {
             var pocket = pocketSupplier.get();
             for (var upgrade : PocketUpgrades.instance().getUpgrades()) {
-                upgradeItems.add(pocket.create(-1, null, -1, UpgradeData.ofDefault(upgrade)));
+                upgradeItems.add(DataComponentUtil.createStack(pocket, ModRegistry.DataComponents.POCKET_UPGRADE.get(), UpgradeData.ofDefault(upgrade)));
             }
         }
 

projects/common/src/main/java/dan200/computercraft/shared/integration/UpgradeRecipeGenerator.java

@@ -11,8 +11,10 @@
 import dan200.computercraft.api.upgrades.UpgradeData;
 import dan200.computercraft.impl.PocketUpgrades;
 import dan200.computercraft.impl.TurtleUpgrades;
+import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
+import dan200.computercraft.shared.util.DataComponentUtil;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
@@ -105,10 +107,10 @@ public boolean isUpgrade(ItemStack stack) {
     public List<T> findRecipesWithInput(ItemStack stack) {
         setupCache();
 
-        if (stack.getItem() instanceof TurtleItem item) {
+        if (stack.getItem() instanceof TurtleItem) {
             // Suggest possible upgrades which can be applied to this turtle
-            var left = item.getUpgradeWithData(stack, TurtleSide.LEFT);
-            var right = item.getUpgradeWithData(stack, TurtleSide.RIGHT);
+            var left = TurtleItem.getUpgradeWithData(stack, TurtleSide.LEFT);
+            var right = TurtleItem.getUpgradeWithData(stack, TurtleSide.RIGHT);
             if (left != null && right != null) return List.of();
 
             List<T> recipes = new ArrayList<>();
@@ -176,11 +178,11 @@ public List<T> findRecipesWithInput(ItemStack stack) {
      */
     public List<T> findRecipesWithOutput(ItemStack stack) {
         // Find which upgrade this item currently has, and so how we could build it.
-        if (stack.getItem() instanceof TurtleItem item) {
+        if (stack.getItem() instanceof TurtleItem) {
             List<T> recipes = new ArrayList<>(0);
 
-            var left = item.getUpgradeWithData(stack, TurtleSide.LEFT);
-            var right = item.getUpgradeWithData(stack, TurtleSide.RIGHT);
+            var left = TurtleItem.getUpgradeWithData(stack, TurtleSide.LEFT);
+            var right = TurtleItem.getUpgradeWithData(stack, TurtleSide.RIGHT);
 
             // The turtle is facing towards us, so upgrades on the left are actually crafted on the right.
             if (left != null) {
@@ -215,18 +217,16 @@ public List<T> findRecipesWithOutput(ItemStack stack) {
     }
 
     private static ItemStack turtleWith(ItemStack stack, @Nullable UpgradeData<ITurtleUpgrade> left, @Nullable UpgradeData<ITurtleUpgrade> right) {
-        var item = (TurtleItem) stack.getItem();
-        return item.create(
-            item.getComputerID(stack), item.getLabel(stack), item.getColour(stack),
-            left, right, item.getFuelLevel(stack), item.getOverlay(stack)
-        );
+        var newStack = stack.copyWithCount(1);
+        newStack.set(ModRegistry.DataComponents.LEFT_TURTLE_UPGRADE.get(), left);
+        newStack.set(ModRegistry.DataComponents.RIGHT_TURTLE_UPGRADE.get(), right);
+        return stack;
     }
 
     private static ItemStack pocketWith(ItemStack stack, @Nullable UpgradeData<IPocketUpgrade> back) {
-        var item = (PocketComputerItem) stack.getItem();
-        return item.create(
-            item.getComputerID(stack), item.getLabel(stack), item.getColour(stack), back
-        );
+        var newStack = stack.copyWithCount(1);
+        newStack.set(ModRegistry.DataComponents.POCKET_UPGRADE.get(), back);
+        return stack;
     }
 
     private T pocket(Ingredient upgrade, Ingredient pocketComputer, ItemStack result) {
@@ -278,8 +278,8 @@ List<T> getRecipes() {
                     var turtleItem = turtleSupplier.get();
                     recipes.add(turtle(
                         ingredient, // Right upgrade, recipe on left
-                        Ingredient.of(turtleItem.create(-1, null, -1, null, null, 0, null)),
-                        turtleItem.create(-1, null, -1, null, UpgradeData.ofDefault(turtle), 0, null)
+                        Ingredient.of(new ItemStack(turtleItem)),
+                        DataComponentUtil.createStack(turtleItem, ModRegistry.DataComponents.RIGHT_TURTLE_UPGRADE.get(), UpgradeData.ofDefault(turtle))
                     ));
                 }
             }
@@ -289,8 +289,8 @@ List<T> getRecipes() {
                     var pocketItem = pocketSupplier.get();
                     recipes.add(pocket(
                         ingredient,
-                        Ingredient.of(pocketItem.create(-1, null, -1, null)),
-                        pocketItem.create(-1, null, -1, UpgradeData.ofDefault(pocket))
+                        Ingredient.of(pocketItem),
+                        DataComponentUtil.createStack(pocketItem, ModRegistry.DataComponents.POCKET_UPGRADE.get(), UpgradeData.ofDefault(pocket))
                     ));
                 }
             }

projects/common/src/main/java/dan200/computercraft/shared/integration/jei/JEIComputerCraft.java

@@ -70,14 +70,11 @@ public void onRuntimeAvailable(IJeiRuntime runtime) {
      * Distinguishes turtles by upgrades and family.
      */
     private static final IIngredientSubtypeInterpreter<ItemStack> turtleSubtype = (stack, ctx) -> {
-        var item = stack.getItem();
-        if (!(item instanceof TurtleItem turtle)) return IIngredientSubtypeInterpreter.NONE;
-
         var name = new StringBuilder("turtle:");
 
         // Add left and right upgrades to the identifier
-        var left = turtle.getUpgrade(stack, TurtleSide.LEFT);
-        var right = turtle.getUpgrade(stack, TurtleSide.RIGHT);
+        var left = TurtleItem.getUpgrade(stack, TurtleSide.LEFT);
+        var right = TurtleItem.getUpgrade(stack, TurtleSide.RIGHT);
         if (left != null) name.append(left.getUpgradeID());
         if (left != null && right != null) name.append('|');
         if (right != null) name.append(right.getUpgradeID());
@@ -89,9 +86,6 @@ public void onRuntimeAvailable(IJeiRuntime runtime) {
      * Distinguishes pocket computers by upgrade and family.
      */
     private static final IIngredientSubtypeInterpreter<ItemStack> pocketSubtype = (stack, ctx) -> {
-        var item = stack.getItem();
-        if (!(item instanceof PocketComputerItem)) return IIngredientSubtypeInterpreter.NONE;
-
         var name = new StringBuilder("pocket:");
 
         // Add the upgrade to the identifier
@@ -104,11 +98,5 @@ public void onRuntimeAvailable(IJeiRuntime runtime) {
     /**
      * Distinguishes disks by colour.
      */
-    private static final IIngredientSubtypeInterpreter<ItemStack> diskSubtype = (stack, ctx) -> {
-        var item = stack.getItem();
-        if (!(item instanceof DiskItem disk)) return IIngredientSubtypeInterpreter.NONE;
-
-        var colour = disk.getColour(stack);
-        return colour == -1 ? IIngredientSubtypeInterpreter.NONE : String.format("%06x", colour);
-    };
+    private static final IIngredientSubtypeInterpreter<ItemStack> diskSubtype = (stack, ctx) -> Integer.toString(DiskItem.getColour(stack));
 }

projects/common/src/main/java/dan200/computercraft/shared/media/items/DiskItem.java

@@ -10,39 +10,29 @@
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.common.IColouredItem;
 import dan200.computercraft.shared.config.Config;
 import net.minecraft.ChatFormatting;
 import net.minecraft.core.BlockPos;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.TooltipFlag;
-import net.minecraft.world.level.Level;
+import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.level.LevelReader;
 
 import javax.annotation.Nullable;
 import java.util.List;
 
-public class DiskItem extends Item implements IMedia, IColouredItem {
-    private static final String NBT_ID = "DiskId";
-
+public class DiskItem extends Item implements IMedia {
     public DiskItem(Properties settings) {
         super(settings);
     }
 
-    public static ItemStack createFromIDAndColour(int id, @Nullable String label, int colour) {
-        var stack = new ItemStack(ModRegistry.Items.DISK.get());
-        setDiskID(stack, id);
-        ModRegistry.Items.DISK.get().setLabel(stack, label);
-        IColouredItem.setColourBasic(stack, colour);
-        return stack;
-    }
-
     @Override
-    public void appendHoverText(ItemStack stack, @Nullable Level world, List<Component> list, TooltipFlag options) {
+    public void appendHoverText(ItemStack stack, TooltipContext context, List<Component> list, TooltipFlag options) {
         if (options.isAdvanced()) {
             var id = getDiskID(stack);
             if (id >= 0) {
@@ -59,16 +49,13 @@ public boolean doesSneakBypassUse(ItemStack stack, LevelReader world, BlockPos p
 
     @Override
     public @Nullable String getLabel(ItemStack stack) {
-        return stack.hasCustomHoverName() ? stack.getHoverName().getString() : null;
+        var label = stack.get(DataComponents.CUSTOM_NAME);
+        return label != null ? label.getString() : null;
     }
 
     @Override
     public boolean setLabel(ItemStack stack, @Nullable String label) {
-        if (label != null) {
-            stack.setHoverName(Component.literal(label));
-        } else {
-            stack.resetHoverName();
-        }
+        stack.set(DataComponents.CUSTOM_NAME, label != null ? Component.literal(label) : null);
         return true;
     }
 
@@ -77,23 +64,17 @@ public boolean setLabel(ItemStack stack, @Nullable String label) {
         var diskID = getDiskID(stack);
         if (diskID < 0) {
             diskID = ComputerCraftAPI.createUniqueNumberedSaveDir(level.getServer(), "disk");
-            setDiskID(stack, diskID);
+            stack.set(ModRegistry.DataComponents.DISK.get(), diskID);
         }
         return ComputerCraftAPI.createSaveDirMount(level.getServer(), "disk/" + diskID, Config.floppySpaceLimit);
     }
 
     public static int getDiskID(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_ID) ? nbt.getInt(NBT_ID) : -1;
+        var id = stack.get(ModRegistry.DataComponents.DISK.get());
+        return id != null ? id : -1;
     }
 
-    private static void setDiskID(ItemStack stack, int id) {
-        if (id >= 0) stack.getOrCreateTag().putInt(NBT_ID, id);
-    }
-
-    @Override
-    public int getColour(ItemStack stack) {
-        var colour = IColouredItem.getColourBasic(stack);
-        return colour == -1 ? Colour.WHITE.getHex() : colour;
+    public static int getColour(ItemStack stack) {
+        return DyedItemColor.getOrDefault(stack, Colour.WHITE.getARGB());
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/media/items/PrintoutData.java

@@ -0,0 +1,67 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.media.items;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import dan200.computercraft.core.terminal.Terminal;
+import io.netty.buffer.ByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+
+import java.util.Arrays;
+import java.util.List;
+
+public record PrintoutData(String title, List<Line> lines) {
+    public static final PrintoutData EMPTY;
+
+    static {
+        var lines = new Line[PrintoutItem.LINES_PER_PAGE];
+        Arrays.fill(lines, Line.EMPTY);
+        EMPTY = new PrintoutData("", List.of(lines));
+    }
+
+    private static final Codec<Line> LINE_CODEC = RecordCodecBuilder.<Line>create(s -> s.group(
+        Codec.STRING.fieldOf("text").forGetter(Line::text),
+        Codec.STRING.fieldOf("foreground").forGetter(Line::foreground)
+    ).apply(s, Line::new)).validate(x -> x.text().length() == x.foreground().length() ? DataResult.success(x) : DataResult.error(() -> "Text and foreground are different lengths"));
+
+    private static final StreamCodec<ByteBuf, Line> LINE_STREAM_CODEC = StreamCodec.composite(
+        ByteBufCodecs.STRING_UTF8, Line::text,
+        ByteBufCodecs.STRING_UTF8, Line::foreground,
+        Line::new
+    );
+
+    public static final Codec<PrintoutData> CODEC = RecordCodecBuilder.<PrintoutData>create(s -> s.group(
+        Codec.STRING.optionalFieldOf("title", "").forGetter(PrintoutData::title),
+        LINE_CODEC.listOf(1, PrintoutItem.MAX_PAGES * PrintoutItem.LINES_PER_PAGE).fieldOf("lines").forGetter(PrintoutData::lines)
+    ).apply(s, PrintoutData::new)).validate(x -> (x.lines().size() % PrintoutItem.LINES_PER_PAGE) == 0 ? DataResult.success(x) : DataResult.error(() -> "Not enough lines for a page."));
+
+    public static final StreamCodec<ByteBuf, PrintoutData> STREAM_CODEC = StreamCodec.composite(
+        ByteBufCodecs.STRING_UTF8, PrintoutData::title,
+        LINE_STREAM_CODEC.apply(ByteBufCodecs.list(PrintoutItem.MAX_PAGES * PrintoutItem.LINES_PER_PAGE)), PrintoutData::lines,
+        PrintoutData::new
+    );
+
+    /**
+     * A single line on our printed pages.
+     *
+     * @param text       The text for this line.
+     * @param foreground The foreground colour of this line, in a format equivalent to {@link Terminal#getTextColourLine(int)}.
+     */
+    public record Line(String text, String foreground) {
+        public static final Line EMPTY = new Line("", "");
+    }
+
+    /**
+     * Get the number of pages in this printout.
+     *
+     * @return The number of pages.
+     */
+    public int pages() {
+        return Math.ceilDiv(lines.size(), PrintoutItem.LINES_PER_PAGE);
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/media/items/PrintoutItem.java

@@ -17,15 +17,9 @@
 import net.minecraft.world.item.TooltipFlag;
 import net.minecraft.world.level.Level;
 
-import javax.annotation.Nullable;
 import java.util.List;
 
 public class PrintoutItem extends Item {
-    private static final String NBT_TITLE = "Title";
-    private static final String NBT_PAGES = "Pages";
-    private static final String NBT_LINE_TEXT = "Text";
-    private static final String NBT_LINE_COLOUR = "Color";
-
     public static final int LINES_PER_PAGE = 21;
     public static final int LINE_MAX_LENGTH = 25;
     public static final int MAX_PAGES = 16;
@@ -44,9 +38,9 @@ public PrintoutItem(Properties settings, Type type) {
     }
 
     @Override
-    public void appendHoverText(ItemStack stack, @Nullable Level world, List<Component> list, TooltipFlag options) {
+    public void appendHoverText(ItemStack stack, TooltipContext context, List<Component> list, TooltipFlag options) {
         var title = getTitle(stack);
-        if (title != null && !title.isEmpty()) list.add(Component.literal(title));
+        if (!title.isEmpty()) list.add(Component.literal(title));
     }
 
     @Override
@@ -58,70 +52,17 @@ public InteractionResultHolder<ItemStack> use(Level world, Player player, Intera
         return new InteractionResultHolder<>(InteractionResult.sidedSuccess(world.isClientSide), player.getItemInHand(hand));
     }
 
-    private ItemStack createFromTitleAndText(@Nullable String title, @Nullable String[] text, @Nullable String[] colours) {
-        var stack = new ItemStack(this);
-
-        // Build NBT
-        if (title != null) stack.getOrCreateTag().putString(NBT_TITLE, title);
-        if (text != null) {
-            var tag = stack.getOrCreateTag();
-            tag.putInt(NBT_PAGES, text.length / LINES_PER_PAGE);
-            for (var i = 0; i < text.length; i++) {
-                if (text[i] != null) tag.putString(NBT_LINE_TEXT + i, text[i]);
-            }
-        }
-        if (colours != null) {
-            var tag = stack.getOrCreateTag();
-            for (var i = 0; i < colours.length; i++) {
-                if (colours[i] != null) tag.putString(NBT_LINE_COLOUR + i, colours[i]);
-            }
-        }
-
-
-        return stack;
-    }
-
-    public static ItemStack createSingleFromTitleAndText(@Nullable String title, @Nullable String[] text, @Nullable String[] colours) {
-        return ModRegistry.Items.PRINTED_PAGE.get().createFromTitleAndText(title, text, colours);
-    }
-
-    public static ItemStack createMultipleFromTitleAndText(@Nullable String title, @Nullable String[] text, @Nullable String[] colours) {
-        return ModRegistry.Items.PRINTED_PAGES.get().createFromTitleAndText(title, text, colours);
-    }
-
-    public static ItemStack createBookFromTitleAndText(@Nullable String title, @Nullable String[] text, @Nullable String[] colours) {
-        return ModRegistry.Items.PRINTED_BOOK.get().createFromTitleAndText(title, text, colours);
-    }
-
     public Type getType() {
         return type;
     }
 
     public static String getTitle(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_TITLE) ? nbt.getString(NBT_TITLE) : "";
+        var nbt = stack.get(ModRegistry.DataComponents.PRINTOUT.get());
+        return nbt == null ? "" : nbt.title();
     }
 
     public static int getPageCount(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_PAGES) ? nbt.getInt(NBT_PAGES) : 1;
-    }
-
-    public static String[] getText(ItemStack stack) {
-        return getLines(stack, NBT_LINE_TEXT);
-    }
-
-    public static String[] getColours(ItemStack stack) {
-        return getLines(stack, NBT_LINE_COLOUR);
-    }
-
-    private static String[] getLines(ItemStack stack, String prefix) {
-        var nbt = stack.getTag();
-        var numLines = getPageCount(stack) * LINES_PER_PAGE;
-        var lines = new String[numLines];
-        for (var i = 0; i < lines.length; i++) {
-            lines[i] = nbt != null ? nbt.getString(prefix + i) : "";
-        }
-        return lines;
+        var nbt = stack.get(ModRegistry.DataComponents.PRINTOUT.get());
+        return nbt == null ? 1 : nbt.pages();
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/media/items/TreasureDisk.java

@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.media.items;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.core.component.DataComponentHolder;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+
+/**
+ * Component for {@linkplain TreasureDiskItem treasure disks}.
+ *
+ * @param name The name/title of the disk.
+ * @param path The subpath to the resource
+ */
+public record TreasureDisk(String name, String path) {
+    public static final Codec<TreasureDisk> CODEC = RecordCodecBuilder.create(i -> i.group(
+        Codec.STRING.fieldOf("name").forGetter(TreasureDisk::name),
+        Codec.STRING.fieldOf("path").forGetter(TreasureDisk::path)
+    ).apply(i, TreasureDisk::new));
+
+    public static final StreamCodec<FriendlyByteBuf, TreasureDisk> STREAM_CODEC = StreamCodec.composite(
+        ByteBufCodecs.STRING_UTF8, TreasureDisk::name,
+        ByteBufCodecs.STRING_UTF8, TreasureDisk::path,
+        TreasureDisk::new
+    );
+
+    public static String getTitle(DataComponentHolder holder) {
+        var nbt = holder.get(ModRegistry.DataComponents.TREASURE_DISK.get());
+        return nbt != null ? nbt.name() : "'missingno' by how did you get this anyway?";
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/media/items/TreasureDiskItem.java

@@ -9,7 +9,6 @@
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.core.filesystem.SubMount;
-import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
@@ -18,7 +17,6 @@
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.TooltipFlag;
-import net.minecraft.world.level.Level;
 import net.minecraft.world.level.LevelReader;
 
 import javax.annotation.Nullable;
@@ -26,18 +24,13 @@
 import java.util.List;
 
 public class TreasureDiskItem extends Item implements IMedia {
-    private static final String NBT_TITLE = "Title";
-    private static final String NBT_COLOUR = "Colour";
-    private static final String NBT_SUB_PATH = "SubPath";
-
     public TreasureDiskItem(Properties settings) {
         super(settings);
     }
 
     @Override
-    public void appendHoverText(ItemStack stack, @Nullable Level world, List<Component> list, TooltipFlag tooltipOptions) {
-        var label = getTitle(stack);
-        if (!label.isEmpty()) list.add(Component.literal(label));
+    public void appendHoverText(ItemStack stack, TooltipContext context, List<Component> list, TooltipFlag tooltipOptions) {
+        list.add(Component.literal(TreasureDisk.getTitle(stack)));
     }
 
     @ForgeOverride
@@ -47,7 +40,7 @@ public boolean doesSneakBypassUse(ItemStack stack, LevelReader world, BlockPos p
 
     @Override
     public String getLabel(ItemStack stack) {
-        return getTitle(stack);
+        return TreasureDisk.getTitle(stack);
     }
 
     @Override
@@ -55,7 +48,10 @@ public String getLabel(ItemStack stack) {
         var rootTreasure = ComputerCraftAPI.createResourceMount(level.getServer(), "computercraft", "lua/treasure");
         if (rootTreasure == null) return null;
 
-        var subPath = getSubPath(stack);
+        var treasureDisk = stack.get(ModRegistry.DataComponents.TREASURE_DISK.get());
+        if (treasureDisk == null) return null;
+
+        var subPath = treasureDisk.path();
         try {
             if (rootTreasure.exists(subPath)) {
                 return new SubMount(rootTreasure, subPath);
@@ -68,37 +64,4 @@ public String getLabel(ItemStack stack) {
             return null;
         }
     }
-
-    public static ItemStack create(String subPath, int colourIndex) {
-        var result = new ItemStack(ModRegistry.Items.TREASURE_DISK.get());
-        var nbt = result.getOrCreateTag();
-        nbt.putString(NBT_SUB_PATH, subPath);
-
-        var slash = subPath.indexOf('/');
-        if (slash >= 0) {
-            var author = subPath.substring(0, slash);
-            var title = subPath.substring(slash + 1);
-            nbt.putString(NBT_TITLE, "\"" + title + "\" by " + author);
-        } else {
-            nbt.putString(NBT_TITLE, "untitled");
-        }
-        nbt.putInt(NBT_COLOUR, Colour.values()[colourIndex].getHex());
-
-        return result;
-    }
-
-    private static String getTitle(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_TITLE) ? nbt.getString(NBT_TITLE) : "'missingno' by how did you get this anyway?";
-    }
-
-    private static String getSubPath(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_SUB_PATH) ? nbt.getString(NBT_SUB_PATH) : "dan200/alongtimeago";
-    }
-
-    public static int getColour(ItemStack stack) {
-        var nbt = stack.getTag();
-        return nbt != null && nbt.contains(NBT_COLOUR) ? nbt.getInt(NBT_COLOUR) : Colour.BLUE.getHex();
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/media/recipes/DiskRecipe.java

@@ -6,14 +6,16 @@
 
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.platform.PlatformHelper;
 import dan200.computercraft.shared.util.ColourTracker;
 import dan200.computercraft.shared.util.ColourUtils;
-import net.minecraft.core.RegistryAccess;
+import dan200.computercraft.shared.util.DataComponentUtil;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
+import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.item.crafting.CraftingBookCategory;
 import net.minecraft.world.item.crafting.CustomRecipe;
 import net.minecraft.world.item.crafting.Ingredient;
@@ -53,7 +55,7 @@ public boolean matches(CraftingContainer inv, Level world) {
     }
 
     @Override
-    public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess) {
+    public ItemStack assemble(CraftingContainer inv, HolderLookup.Provider registryAccess) {
         var tracker = new ColourTracker();
 
         for (var i = 0; i < inv.getContainerSize(); i++) {
@@ -67,7 +69,7 @@ public ItemStack assemble(CraftingContainer inv, RegistryAccess registryAccess)
             }
         }
 
-        return DiskItem.createFromIDAndColour(-1, null, tracker.hasColour() ? tracker.getColour() : Colour.BLUE.getHex());
+        return DataComponentUtil.createStack(ModRegistry.Items.DISK.get(), DataComponents.DYED_COLOR, new DyedItemColor(tracker.hasColour() ? tracker.getColour() : Colour.BLUE.getHex(), false));
     }
 
     @Override
@@ -76,8 +78,8 @@ public boolean canCraftInDimensions(int x, int y) {
     }
 
     @Override
-    public ItemStack getResultItem(RegistryAccess registryAccess) {
-        return DiskItem.createFromIDAndColour(-1, null, Colour.BLUE.getHex());
+    public ItemStack getResultItem(HolderLookup.Provider registryAccess) {
+        return DataComponentUtil.createStack(ModRegistry.Items.DISK.get(), DataComponents.DYED_COLOR, new DyedItemColor(Colour.BLUE.getHex(), false));
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/media/recipes/PrintoutRecipe.java

@@ -5,9 +5,11 @@
 package dan200.computercraft.shared.media.recipes;
 
 import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.media.items.PrintoutData;
 import dan200.computercraft.shared.media.items.PrintoutItem;
 import dan200.computercraft.shared.platform.PlatformHelper;
-import net.minecraft.core.RegistryAccess;
+import dan200.computercraft.shared.util.DataComponentUtil;
+import net.minecraft.core.HolderLookup;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
@@ -17,6 +19,8 @@
 import net.minecraft.world.item.crafting.RecipeSerializer;
 import net.minecraft.world.level.Level;
 
+import java.util.List;
+
 public final class PrintoutRecipe extends CustomRecipe {
     private final Ingredient leather;
     private final Ingredient string;
@@ -35,8 +39,8 @@ public boolean canCraftInDimensions(int x, int y) {
     }
 
     @Override
-    public ItemStack getResultItem(RegistryAccess registryAccess) {
-        return PrintoutItem.createMultipleFromTitleAndText(null, null, null);
+    public ItemStack getResultItem(HolderLookup.Provider registryAccess) {
+        return new ItemStack(ModRegistry.Items.PRINTED_PAGES.get());
     }
 
     @Override
@@ -45,7 +49,7 @@ public boolean matches(CraftingContainer inventory, Level world) {
     }
 
     @Override
-    public ItemStack assemble(CraftingContainer inventory, RegistryAccess registryAccess) {
+    public ItemStack assemble(CraftingContainer inventory, HolderLookup.Provider registryAccess) {
         // See if we match the recipe, and extract the input disk ID and dye colour
         var numPages = 0;
         var numPrintouts = 0;
@@ -84,41 +88,28 @@ public ItemStack assemble(CraftingContainer inventory, RegistryAccess registryAc
         // Build some pages with what was passed in
         if (numPages <= PrintoutItem.MAX_PAGES && stringFound && printoutFound && numPrintouts >= (leatherFound ? 1 : 2)) {
             if (printouts == null) throw new IllegalStateException("Printouts must be non-null");
-            var text = new String[numPages * PrintoutItem.LINES_PER_PAGE];
-            var colours = new String[numPages * PrintoutItem.LINES_PER_PAGE];
+            var lines = new PrintoutData.Line[numPages * PrintoutItem.LINES_PER_PAGE];
             var line = 0;
 
             for (var printout = 0; printout < numPrintouts; printout++) {
-                var stack = printouts[printout];
-                if (stack.getItem() instanceof PrintoutItem) {
+                var pageText = printouts[printout].get(ModRegistry.DataComponents.PRINTOUT.get());
+                if (pageText != null) {
                     // Add a printout
-                    var pageText = PrintoutItem.getText(printouts[printout]);
-                    var pageColours = PrintoutItem.getColours(printouts[printout]);
-                    for (var pageLine = 0; pageLine < pageText.length; pageLine++) {
-                        text[line] = pageText[pageLine];
-                        colours[line] = pageColours[pageLine];
-                        line++;
-                    }
+                    for (var pageLine : pageText.lines()) lines[line++] = pageLine;
                 } else {
                     // Add a blank page
                     for (var pageLine = 0; pageLine < PrintoutItem.LINES_PER_PAGE; pageLine++) {
-                        text[line] = "";
-                        colours[line] = "";
-                        line++;
+                        lines[line++] = PrintoutData.Line.EMPTY;
                     }
                 }
             }
 
-            String title = null;
-            if (printouts[0].getItem() instanceof PrintoutItem) {
-                title = PrintoutItem.getTitle(printouts[0]);
-            }
+            var title = PrintoutItem.getTitle(printouts[0]);
 
-            if (leatherFound) {
-                return PrintoutItem.createBookFromTitleAndText(title, text, colours);
-            } else {
-                return PrintoutItem.createMultipleFromTitleAndText(title, text, colours);
-            }
+            return DataComponentUtil.createStack(
+                leatherFound ? ModRegistry.Items.PRINTED_BOOK.get() : ModRegistry.Items.PRINTED_PAGES.get(),
+                ModRegistry.DataComponents.PRINTOUT.get(), new PrintoutData(title, List.of(lines))
+            );
         }
 
         return ItemStack.EMPTY;

projects/common/src/main/java/dan200/computercraft/shared/network/MessageType.java

@@ -1,28 +0,0 @@
-// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.network;
-
-import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
-import net.minecraft.resources.ResourceLocation;
-
-/**
- * A type of message to send over the network.
- * <p>
- * Much like recipe or argument serialisers, each type of {@link NetworkMessage} should have a unique type associated
- * with it. This holds platform-specific information about how the packet should be sent over the network.
- *
- * @param <T> The type of message to send
- * @see NetworkMessages
- * @see NetworkMessage#type()
- */
-public interface MessageType<T extends NetworkMessage<?>> {
-    /**
-     * Get the id of this message type. This will be used as the custom packet channel name.
-     *
-     * @return The id of this message type.
-     * @see CustomPacketPayload#id()
-     */
-    ResourceLocation id();
-}

projects/common/src/main/java/dan200/computercraft/shared/network/NetworkMessage.java

@@ -6,8 +6,7 @@
 
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.network.server.ServerNetworkContext;
-import net.minecraft.network.FriendlyByteBuf;
-
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 
 /**
  * The base interface for any message which will be sent to the client or server.
@@ -16,23 +15,7 @@
  * @see ClientNetworkContext
  * @see ServerNetworkContext
  */
-public interface NetworkMessage<T> {
-    /**
-     * Get the type of this message.
-     *
-     * @return The type of this message.
-     */
-    MessageType<?> type();
-
-    /**
-     * Write this packet to a buffer.
-     * <p>
-     * This may be called on any thread, so this should be a pure operation.
-     *
-     * @param buf The buffer to write data to.
-     */
-    void write(FriendlyByteBuf buf);
-
+public interface NetworkMessage<T> extends CustomPacketPayload {
     /**
      * Handle this {@link NetworkMessage}.
      *

projects/common/src/main/java/dan200/computercraft/shared/network/NetworkMessages.java

@@ -8,59 +8,61 @@
 import dan200.computercraft.shared.network.client.*;
 import dan200.computercraft.shared.network.server.*;
 import dan200.computercraft.shared.platform.PlatformHelper;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 import net.minecraft.resources.ResourceLocation;
 
 import java.util.*;
 
 /**
- * List of all {@link MessageType}s provided by CC: Tweaked.
+ * List of all {@link CustomPacketPayload.Type}s provided by CC: Tweaked.
  *
  * @see PlatformHelper The platform helper is used to send packets.
  */
 public final class NetworkMessages {
     private static final Set<String> seenChannel = new HashSet<>();
-    private static final List<MessageType<? extends NetworkMessage<ServerNetworkContext>>> serverMessages = new ArrayList<>();
-    private static final List<MessageType<? extends NetworkMessage<ClientNetworkContext>>> clientMessages = new ArrayList<>();
+    private static final List<CustomPacketPayload.TypeAndCodec<RegistryFriendlyByteBuf, ? extends NetworkMessage<ServerNetworkContext>>> serverMessages = new ArrayList<>();
+    private static final List<CustomPacketPayload.TypeAndCodec<RegistryFriendlyByteBuf, ? extends NetworkMessage<ClientNetworkContext>>> clientMessages = new ArrayList<>();
 
-    public static final MessageType<ComputerActionServerMessage> COMPUTER_ACTION = registerServerbound("computer_action", ComputerActionServerMessage::new);
-    public static final MessageType<QueueEventServerMessage> QUEUE_EVENT = registerServerbound("queue_event", QueueEventServerMessage::new);
-    public static final MessageType<KeyEventServerMessage> KEY_EVENT = registerServerbound("key_event", KeyEventServerMessage::new);
-    public static final MessageType<MouseEventServerMessage> MOUSE_EVENT = registerServerbound("mouse_event", MouseEventServerMessage::new);
-    public static final MessageType<UploadFileMessage> UPLOAD_FILE = registerServerbound("upload_file", UploadFileMessage::new);
+    public static final CustomPacketPayload.Type<ComputerActionServerMessage> COMPUTER_ACTION = registerServerbound("computer_action", ComputerActionServerMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<QueueEventServerMessage> QUEUE_EVENT = register(serverMessages, "queue_event", QueueEventServerMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<KeyEventServerMessage> KEY_EVENT = registerServerbound("key_event", KeyEventServerMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<MouseEventServerMessage> MOUSE_EVENT = registerServerbound("mouse_event", MouseEventServerMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<UploadFileMessage> UPLOAD_FILE = register(serverMessages, "upload_file", UploadFileMessage.STREAM_CODEC);
 
-    public static final MessageType<ChatTableClientMessage> CHAT_TABLE = registerClientbound("chat_table", ChatTableClientMessage::new);
-    public static final MessageType<PocketComputerDataMessage> POCKET_COMPUTER_DATA = registerClientbound("pocket_computer_data", PocketComputerDataMessage::new);
-    public static final MessageType<PocketComputerDeletedClientMessage> POCKET_COMPUTER_DELETED = registerClientbound("pocket_computer_deleted", PocketComputerDeletedClientMessage::new);
-    public static final MessageType<ComputerTerminalClientMessage> COMPUTER_TERMINAL = registerClientbound("computer_terminal", ComputerTerminalClientMessage::new);
-    public static final MessageType<PlayRecordClientMessage> PLAY_RECORD = registerClientbound("play_record", PlayRecordClientMessage::new);
-    public static final MessageType<MonitorClientMessage> MONITOR_CLIENT = registerClientbound("monitor_client", MonitorClientMessage::new);
-    public static final MessageType<SpeakerAudioClientMessage> SPEAKER_AUDIO = registerClientbound("speaker_audio", SpeakerAudioClientMessage::new);
-    public static final MessageType<SpeakerMoveClientMessage> SPEAKER_MOVE = registerClientbound("speaker_move", SpeakerMoveClientMessage::new);
-    public static final MessageType<SpeakerPlayClientMessage> SPEAKER_PLAY = registerClientbound("speaker_play", SpeakerPlayClientMessage::new);
-    public static final MessageType<SpeakerStopClientMessage> SPEAKER_STOP = registerClientbound("speaker_stop", SpeakerStopClientMessage::new);
-    public static final MessageType<UploadResultMessage> UPLOAD_RESULT = registerClientbound("upload_result", UploadResultMessage::new);
-    public static final MessageType<UpgradesLoadedMessage> UPGRADES_LOADED = registerClientbound("upgrades_loaded", UpgradesLoadedMessage::new);
+    public static final CustomPacketPayload.Type<ChatTableClientMessage> CHAT_TABLE = registerClientbound("chat_table", ChatTableClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<PocketComputerDataMessage> POCKET_COMPUTER_DATA = registerClientbound("pocket_computer_data", PocketComputerDataMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<PocketComputerDeletedClientMessage> POCKET_COMPUTER_DELETED = registerClientbound("pocket_computer_deleted", PocketComputerDeletedClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<ComputerTerminalClientMessage> COMPUTER_TERMINAL = registerClientbound("computer_terminal", ComputerTerminalClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<PlayRecordClientMessage> PLAY_RECORD = registerClientbound("play_record", PlayRecordClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<MonitorClientMessage> MONITOR_CLIENT = registerClientbound("monitor_client", MonitorClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<SpeakerAudioClientMessage> SPEAKER_AUDIO = registerClientbound("speaker_audio", SpeakerAudioClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<SpeakerMoveClientMessage> SPEAKER_MOVE = registerClientbound("speaker_move", SpeakerMoveClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<SpeakerPlayClientMessage> SPEAKER_PLAY = registerClientbound("speaker_play", SpeakerPlayClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<SpeakerStopClientMessage> SPEAKER_STOP = registerClientbound("speaker_stop", SpeakerStopClientMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<UploadResultMessage> UPLOAD_RESULT = registerClientbound("upload_result", UploadResultMessage.STREAM_CODEC);
+    public static final CustomPacketPayload.Type<UpgradesLoadedMessage> UPGRADES_LOADED = registerClientbound("upgrades_loaded", UpgradesLoadedMessage.STREAM_CODEC);
 
     private NetworkMessages() {
     }
 
-    private static <C, T extends NetworkMessage<C>> MessageType<T> register(
-        List<MessageType<? extends NetworkMessage<C>>> messages,
-        String channel, FriendlyByteBuf.Reader<T> reader
+    private static <C, T extends NetworkMessage<C>> CustomPacketPayload.Type<T> register(
+        List<CustomPacketPayload.TypeAndCodec<RegistryFriendlyByteBuf, ? extends NetworkMessage<C>>> messages,
+        String channel, StreamCodec<RegistryFriendlyByteBuf, T> codec
     ) {
         if (!seenChannel.add(channel)) throw new IllegalArgumentException("Duplicate channel " + channel);
-        var type = PlatformHelper.get().createMessageType(new ResourceLocation(ComputerCraftAPI.MOD_ID, channel), reader);
-        messages.add(type);
+        var type = new CustomPacketPayload.Type<T>(new ResourceLocation(ComputerCraftAPI.MOD_ID, channel));
+        messages.add(new CustomPacketPayload.TypeAndCodec<>(type, codec));
         return type;
     }
 
-    private static <T extends NetworkMessage<ServerNetworkContext>> MessageType<T> registerServerbound(String id, FriendlyByteBuf.Reader<T> reader) {
-        return register(serverMessages, id, reader);
+    private static <T extends NetworkMessage<ServerNetworkContext>> CustomPacketPayload.Type<T> registerServerbound(String id, StreamCodec<RegistryFriendlyByteBuf, T> codec) {
+        return register(serverMessages, id, codec);
     }
 
-    private static <T extends NetworkMessage<ClientNetworkContext>> MessageType<T> registerClientbound(String id, FriendlyByteBuf.Reader<T> reader) {
-        return register(clientMessages, id, reader);
+    private static <T extends NetworkMessage<ClientNetworkContext>> CustomPacketPayload.Type<T> registerClientbound(String id, StreamCodec<RegistryFriendlyByteBuf, T> codec) {
+        return register(clientMessages, id, codec);
     }
 
     /**
@@ -68,7 +70,7 @@ private static <T extends NetworkMessage<ClientNetworkContext>> MessageType<T> r
      *
      * @return An unmodifiable sequence of all serverbound message types.
      */
-    public static Collection<MessageType<? extends NetworkMessage<ServerNetworkContext>>> getServerbound() {
+    public static Collection<CustomPacketPayload.TypeAndCodec<RegistryFriendlyByteBuf, ? extends NetworkMessage<ServerNetworkContext>>> getServerbound() {
         return Collections.unmodifiableCollection(serverMessages);
     }
 
@@ -77,7 +79,7 @@ public static Collection<MessageType<? extends NetworkMessage<ServerNetworkConte
      *
      * @return An unmodifiable sequence of all clientbound message types.
      */
-    public static Collection<MessageType<? extends NetworkMessage<ClientNetworkContext>>> getClientbound() {
+    public static Collection<CustomPacketPayload.TypeAndCodec<RegistryFriendlyByteBuf, ? extends NetworkMessage<ClientNetworkContext>>> getClientbound() {
         return Collections.unmodifiableCollection(clientMessages);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/ChatTableClientMessage.java

@@ -5,14 +5,18 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.command.text.TableBuilder;
-import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.NetworkMessages;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.ComponentSerialization;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 
 
 public class ChatTableClientMessage implements NetworkMessage<ClientNetworkContext> {
+    public static final StreamCodec<RegistryFriendlyByteBuf, ChatTableClientMessage> STREAM_CODEC = StreamCodec.ofMember(ChatTableClientMessage::write, ChatTableClientMessage::new);
+
     private static final int MAX_LEN = 16;
     private final TableBuilder table;
 
@@ -21,13 +25,13 @@ public ChatTableClientMessage(TableBuilder table) {
         this.table = table;
     }
 
-    public ChatTableClientMessage(FriendlyByteBuf buf) {
+    private ChatTableClientMessage(RegistryFriendlyByteBuf buf) {
         var id = buf.readUtf(MAX_LEN);
         var columns = buf.readVarInt();
         TableBuilder table;
         if (buf.readBoolean()) {
             var headers = new Component[columns];
-            for (var i = 0; i < columns; i++) headers[i] = buf.readComponent();
+            for (var i = 0; i < columns; i++) headers[i] = ComponentSerialization.STREAM_CODEC.decode(buf);
             table = new TableBuilder(id, headers);
         } else {
             table = new TableBuilder(id);
@@ -36,7 +40,7 @@ public ChatTableClientMessage(FriendlyByteBuf buf) {
         var rows = buf.readVarInt();
         for (var i = 0; i < rows; i++) {
             var row = new Component[columns];
-            for (var j = 0; j < columns; j++) row[j] = buf.readComponent();
+            for (var j = 0; j < columns; j++) row[j] = ComponentSerialization.STREAM_CODEC.decode(buf);
             table.row(row);
         }
 
@@ -44,18 +48,17 @@ public ChatTableClientMessage(FriendlyByteBuf buf) {
         this.table = table;
     }
 
-    @Override
-    public void write(FriendlyByteBuf buf) {
+    private void write(RegistryFriendlyByteBuf buf) {
         buf.writeUtf(table.getId(), MAX_LEN);
         buf.writeVarInt(table.getColumns());
         buf.writeBoolean(table.getHeaders() != null);
         if (table.getHeaders() != null) {
-            for (var header : table.getHeaders()) buf.writeComponent(header);
+            for (var header : table.getHeaders()) ComponentSerialization.STREAM_CODEC.encode(buf, header);
         }
 
         buf.writeVarInt(table.getRows().size());
         for (var row : table.getRows()) {
-            for (var column : row) buf.writeComponent(column);
+            for (var column : row) ComponentSerialization.STREAM_CODEC.encode(buf, column);
         }
 
         buf.writeVarInt(table.getAdditional());
@@ -67,7 +70,7 @@ public void handle(ClientNetworkContext context) {
     }
 
     @Override
-    public MessageType<ChatTableClientMessage> type() {
+    public CustomPacketPayload.Type<ChatTableClientMessage> type() {
         return NetworkMessages.CHAT_TABLE;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/ComputerTerminalClientMessage.java

@@ -4,32 +4,33 @@
 
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
-import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.NetworkMessages;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
-
-public class ComputerTerminalClientMessage implements NetworkMessage<ClientNetworkContext> {
-    private final int containerId;
-    private final TerminalState terminal;
+/**
+ * Update the terminal for the currently opened {@link ComputerMenu}.
+ *
+ * @param containerId The currently opened container id.
+ * @param terminal    The new terminal data.
+ */
+public record ComputerTerminalClientMessage(
+    int containerId, TerminalState terminal
+) implements NetworkMessage<ClientNetworkContext> {
+    public static final StreamCodec<RegistryFriendlyByteBuf, ComputerTerminalClientMessage> STREAM_CODEC = StreamCodec.composite(
+        ByteBufCodecs.VAR_INT, ComputerTerminalClientMessage::containerId,
+        TerminalState.STREAM_CODEC, ComputerTerminalClientMessage::terminal,
+        ComputerTerminalClientMessage::new
+    );
 
     public ComputerTerminalClientMessage(AbstractContainerMenu menu, TerminalState terminal) {
-        containerId = menu.containerId;
-        this.terminal = terminal;
-    }
-
-    public ComputerTerminalClientMessage(FriendlyByteBuf buf) {
-        containerId = buf.readVarInt();
-        terminal = new TerminalState(buf);
-    }
-
-    @Override
-    public void write(FriendlyByteBuf buf) {
-        buf.writeVarInt(containerId);
-        terminal.write(buf);
+        this(menu.containerId, terminal);
     }
 
     @Override
@@ -38,7 +39,7 @@ public void handle(ClientNetworkContext context) {
     }
 
     @Override
-    public MessageType<ComputerTerminalClientMessage> type() {
+    public CustomPacketPayload.Type<ComputerTerminalClientMessage> type() {
         return NetworkMessages.COMPUTER_TERMINAL;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/MonitorClientMessage.java

@@ -5,40 +5,34 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.computer.terminal.TerminalState;
-import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.NetworkMessages;
 import net.minecraft.core.BlockPos;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 
-
-public class MonitorClientMessage implements NetworkMessage<ClientNetworkContext> {
-    private final BlockPos pos;
-    private final TerminalState state;
-
-    public MonitorClientMessage(BlockPos pos, TerminalState state) {
-        this.pos = pos;
-        this.state = state;
-    }
-
-    public MonitorClientMessage(FriendlyByteBuf buf) {
-        pos = buf.readBlockPos();
-        state = new TerminalState(buf);
-    }
-
-    @Override
-    public void write(FriendlyByteBuf buf) {
-        buf.writeBlockPos(pos);
-        state.write(buf);
-    }
+/**
+ * Update the terminal contents of a monitor.
+ *
+ * @param pos      The position of the origin monitor.
+ * @param terminal The current monitor terminal.
+ */
+public record MonitorClientMessage(BlockPos pos,
+                                   TerminalState terminal) implements NetworkMessage<ClientNetworkContext> {
+    public static final StreamCodec<RegistryFriendlyByteBuf, MonitorClientMessage> STREAM_CODEC = StreamCodec.composite(
+        BlockPos.STREAM_CODEC, MonitorClientMessage::pos,
+        TerminalState.STREAM_CODEC, MonitorClientMessage::terminal,
+        MonitorClientMessage::new
+    );
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handleMonitorData(pos, state);
+        context.handleMonitorData(pos, terminal);
     }
 
     @Override
-    public MessageType<MonitorClientMessage> type() {
+    public CustomPacketPayload.Type<MonitorClientMessage> type() {
         return NetworkMessages.MONITOR_CLIENT;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/PlayRecordClientMessage.java

@@ -4,60 +4,50 @@
 
 package dan200.computercraft.shared.network.client;
 
-import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.peripheral.diskdrive.DiskDriveBlockEntity;
 import net.minecraft.core.BlockPos;
-import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.core.Holder;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 import net.minecraft.sounds.SoundEvent;
 
-import javax.annotation.Nullable;
+import java.util.Optional;
 
 /**
  * Starts or stops a record on the client, depending on if {@link #soundEvent} is {@code null}.
  * <p>
  * Used by disk drives to play record items.
  *
+ * @param pos        The position of the speaker, where we should play this sound.
+ * @param soundEvent The sound to play, or {@link Optional#empty()} if we should stop playing.
+ * @param name       The title of the audio to play.
  * @see DiskDriveBlockEntity
  */
-public class PlayRecordClientMessage implements NetworkMessage<ClientNetworkContext> {
-    private final BlockPos pos;
-    private final @Nullable String name;
-    private final @Nullable SoundEvent soundEvent;
-
-    public PlayRecordClientMessage(BlockPos pos, SoundEvent event, @Nullable String name) {
-        this.pos = pos;
-        this.name = name;
-        soundEvent = event;
-    }
+public record PlayRecordClientMessage(
+    BlockPos pos, Optional<Holder<SoundEvent>> soundEvent, Optional<String> name
+) implements NetworkMessage<ClientNetworkContext> {
+    public static final StreamCodec<RegistryFriendlyByteBuf, PlayRecordClientMessage> STREAM_CODEC = StreamCodec.composite(
+        BlockPos.STREAM_CODEC, PlayRecordClientMessage::pos,
+        ByteBufCodecs.optional(SoundEvent.STREAM_CODEC), PlayRecordClientMessage::soundEvent,
+        ByteBufCodecs.optional(ByteBufCodecs.STRING_UTF8), PlayRecordClientMessage::name,
+        PlayRecordClientMessage::new
+    );
 
     public PlayRecordClientMessage(BlockPos pos) {
-        this.pos = pos;
-        name = null;
-        soundEvent = null;
-    }
-
-    public PlayRecordClientMessage(FriendlyByteBuf buf) {
-        pos = buf.readBlockPos();
-        soundEvent = buf.readNullable(SoundEvent::readFromNetwork);
-        name = buf.readNullable(FriendlyByteBuf::readUtf);
-    }
-
-    @Override
-    public void write(FriendlyByteBuf buf) {
-        buf.writeBlockPos(pos);
-        buf.writeNullable(soundEvent, (b, e) -> e.writeToNetwork(b));
-        buf.writeNullable(name, FriendlyByteBuf::writeUtf);
+        this(pos, Optional.empty(), Optional.empty());
     }
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handlePlayRecord(pos, soundEvent, name);
+        context.handlePlayRecord(pos, soundEvent.map(Holder::value).orElse(null), name.orElse(null));
     }
 
     @Override
-    public MessageType<PlayRecordClientMessage> type() {
+    public CustomPacketPayload.Type<PlayRecordClientMessage> type() {
         return NetworkMessages.PLAY_RECORD;
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/PocketComputerDataMessage.java

@@ -5,54 +5,56 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.computer.core.ComputerState;
+import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
-import dan200.computercraft.shared.network.MessageType;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.NetworkMessages;
 import dan200.computercraft.shared.pocket.core.PocketServerComputer;
-import net.minecraft.network.FriendlyByteBuf;
+import dan200.computercraft.shared.recipe.MoreStreamCodecs;
+import net.minecraft.core.UUIDUtil;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 
 import java.util.UUID;
 
 /**
  * Provides additional data about a client computer, such as its ID and current state.
+ *
+ * @param id         The {@linkplain ServerComputer#getInstanceUUID() instance id} of the pocket computer.
+ * @param state      Whether the computer is on, off, or blinking.
+ * @param lightState The colour of the light, or {@code -1} if off.
+ * @param terminal   The computer's terminal. This may be absent, in which case the terminal will not be updated on.
  */
-public class PocketComputerDataMessage implements NetworkMessage<ClientNetworkContext> {
-    private final UUID clientId;
-    private final ComputerState state;
-    private final int lightState;
-    private final TerminalState terminal;
+public record PocketComputerDataMessage(
+    UUID id, ComputerState state, int lightState, TerminalState terminal
+) implements NetworkMessage<ClientNetworkContext> {
+    public static final StreamCodec<RegistryFriendlyByteBuf, PocketComputerDataMessage> STREAM_CODEC = StreamCodec.composite(
+        UUIDUtil.STREAM_CODEC, PocketComputerDataMessage::id,
+        MoreStreamCodecs.ofEnum(ComputerState.class), PocketComputerDataMessage::state,
+        ByteBufCodecs.VAR_INT, PocketComputerDataMessage::lightState,
+        TerminalState.STREAM_CODEC, PocketComputerDataMessage::terminal,
+        PocketComputerDataMessage::new
+    );
 
     public PocketComputerDataMessage(PocketServerComputer computer, boolean sendTerminal) {
-        clientId = computer.getInstanceUUID();
-        state = computer.getState();
-        lightState = computer.getLight();
-        terminal = sendTerminal ? computer.getTerminalState() : new TerminalState((NetworkedTerminal) null);
-    }
-
-    public PocketComputerDataMessage(FriendlyByteBuf buf) {
-        clientId = buf.readUUID();
-        state = buf.readEnum(ComputerState.class);
-        lightState = buf.readVarInt();
-        terminal = new TerminalState(buf);
-    }
-
-    @Override
-    public void write(FriendlyByteBuf buf) {
-        buf.writeUUID(clientId);
-        buf.writeEnum(state);
-        buf.writeVarInt(lightState);
-        terminal.write(buf);
+        this(
+            computer.getInstanceUUID(),
+            computer.getState(),
+            computer.getLight(),
+            sendTerminal ? computer.getTerminalState() : new TerminalState((NetworkedTerminal) null)
+        );
     }
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handlePocketComputerData(clientId, state, lightState, terminal);
+        context.handlePocketComputerData(id, state, lightState, terminal);
     }
 
     @Override
-    public MessageType<PocketComputerDataMessage> type() {
+    public CustomPacketPayload.Type<PocketComputerDataMessage> type() {
         return NetworkMessages.POCKET_COMPUTER_DATA;
     }
 }