Show message offering to create a page that does not exist yet

handlers.go

@@ -42,6 +42,10 @@ func HandlerZen(w http.ResponseWriter, rq *http.Request) {
 func HandlerView(w http.ResponseWriter, rq *http.Request) {
 	if rev, ok := HandlerBase(w, rq); ok {
 		rev.ActionView(w, HyphaPage)
+	} else { // Hypha does not exist
+		log.Println("Hypha does not exist, showing 404")
+		w.WriteHeader(http.StatusNotFound)
+		w.Write([]byte(Hypha404(mux.Vars(rq)["hypha"])))
 	}
 }
 

render.go

@@ -22,19 +22,29 @@ func EditHyphaPage(name, textMime, content, tags string) string {
 	return renderBase(renderFromMap(page, "Hypha/edit/index.html"), keys)
 }
 
+// Hypha404 returns 404 page for nonexistent page.
+func Hypha404(name string) string {
+	return HyphaGeneric(name, name, "Hypha/view/404.html")
+}
+
 // HyphaPage returns HTML page of hypha viewer.
 func HyphaPage(rev Revision, content string) string {
+	return HyphaGeneric(rev.FullName, content, "Hypha/view/index.html")
+}
+
+// HyphaGeneric is used when building renderers for all types of hypha pages
+func HyphaGeneric(name string, content, templatePath string) string {
 	sidebar := DefaultSidebar
 	if bside := renderFromMap(map[string]string{
-		"Tree": GetTree(rev.FullName, true).AsHtml(),
+		"Tree": GetTree(name, true).AsHtml(),
 	}, "Hypha/view/sidebar.html"); bside != "" {
 		sidebar = bside
 	}
 	keys := map[string]string{
-		"Title":   fmt.Sprintf(TitleTemplate, rev.FullName),
+		"Title":   fmt.Sprintf(TitleTemplate, name),
 		"Sidebar": sidebar,
 	}
-	return renderBase(renderFromString(content, "Hypha/view/index.html"), keys)
+	return renderBase(renderFromString(content, templatePath), keys)
 }
 
 // renderBase collects and renders page from base template

w/m/Fungus/1.markdown

@@ -0,0 +1 @@
+A **fungus** is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, which is separate from the other eukaryotic life kingdoms of plants and animals.

w/m/Fungus/Amanita Muscaria/1.markdown

@@ -0,0 +1,3 @@
+Amanita muscaria, commonly known as the fly agaric or fly amanita, is a basidiomycete of the genus Amanita. It is also a muscimol mushroom. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine and birch plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees.
+
+It is not an [](Apple)!

w/m/Fungus/Amanita Muscaria/2.markdown

@@ -0,0 +1,4 @@
+Amanita muscaria, commonly known as the fly agaric or fly amanita, is a basidiomycete of the genus Amanita. It is also a muscimol mushroom. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine and birch plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees.
+
+It is not an [Apple](Apple)!
+			

w/m/Fungus/Amanita Muscaria/3.markdown

@@ -0,0 +1,5 @@
+Amanita muscaria, commonly known as the fly agaric or fly amanita, is a basidiomycete of the genus Amanita. It is also a muscimol mushroom. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine and birch plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees.
+
+It is not an [Apple](/Apple)!
+			
+			

w/m/Fungus/Amanita Muscaria/4.markdown

@@ -0,0 +1,6 @@
+Amanita muscaria, commonly known as the fly agaric or fly amanita, is a basidiomycete of the genus Amanita. It is also a muscimol mushroom. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine and birch plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees.
+
+It is not an [Apple](/Fruit/Apple)!
+			
+			
+			

w/m/Fungus/Amanita Muscaria/meta.json

@@ -0,0 +1,58 @@
+{
+	"views": 0,
+	"deleted": false,
+	"revisions": {
+		"1": {
+			"tags": [
+				""
+			],
+			"name": "Amanita Muscaria",
+			"comment": "Update Fungus/Amanita Muscaria",
+			"author": "",
+			"time": 1592836062,
+			"text_mime": "text/markdown",
+			"binary_mime": "",
+			"text_name": "1.markdown",
+			"binary_name": ""
+		},
+		"2": {
+			"tags": [
+				""
+			],
+			"name": "Amanita Muscaria",
+			"comment": "Update Fungus/Amanita Muscaria",
+			"author": "",
+			"time": 1592836073,
+			"text_mime": "text/markdown",
+			"binary_mime": "",
+			"text_name": "2.markdown",
+			"binary_name": ""
+		},
+		"3": {
+			"tags": [
+				""
+			],
+			"name": "Amanita Muscaria",
+			"comment": "Update Fungus/Amanita Muscaria",
+			"author": "",
+			"time": 1592836084,
+			"text_mime": "text/markdown",
+			"binary_mime": "",
+			"text_name": "3.markdown",
+			"binary_name": ""
+		},
+		"4": {
+			"tags": [
+				""
+			],
+			"name": "Amanita Muscaria",
+			"comment": "Update Fungus/Amanita Muscaria",
+			"author": "",
+			"time": 1592836099,
+			"text_mime": "text/markdown",
+			"binary_mime": "",
+			"text_name": "4.markdown",
+			"binary_name": ""
+		}
+	}
+}

w/m/Fungus/Amanita Regalis/1.markdown

@@ -0,0 +1,7 @@
+Шляпка 7—16(20) см в диаметре, полушаровидная, раскрывающаяся до выпуклой и почти плоской со слабо вдавленным центром, с радиально разлинованным краем. Окраска тёмно-умброво-коричневая, оливково-охристая, охристо-коричневая, иногда серо-жёлтая, в центре более интенсивная. Общее покрывало на молодых грибах опушённое, ярко-жёлтое, затем остаётся в виде легко смываемых обрывков, на солнце белеющих, а к старости иногда становящихся серо-жёлтыми.
+
+
+Пластинки частые, сначала узко-приросшие к ножке, затем свободные от неё, кремовые, с многочисленными пластиночками разной длины.
+
+
+Ножка достигает 9—20 см в высоту и 1—2,5 см в поперечнике, утончающаяся кверху, в основании с яйцевидным или шаровидным утолщением. Поверхность ножки волокнисто-бархатистая, белая или беловатая, при прикосновении иногда слабо буреющая. Кольцо в верхней части ножки, беловатое, перепончатое, не разлинованное. Остатки общего покрывала в виде нескольких поясков желтоватых бородавчатых хлопьев на утолщении ножки.

w/m/Fungus/Amanita Regalis/meta.json

@@ -0,0 +1,19 @@
+{
+	"views": 0,
+	"deleted": false,
+	"revisions": {
+		"1": {
+			"tags": [
+				""
+			],
+			"name": "Amanita Regalis",
+			"comment": "Update Fungus/Amanita Regalis",
+			"author": "",
+			"time": 1592838045,
+			"text_mime": "text/markdown",
+			"binary_mime": "image/jpeg",
+			"text_name": "1.markdown",
+			"binary_name": "1.jpeg"
+		}
+	}
+}

w/m/Fungus/meta.json

@@ -0,0 +1,19 @@
+{
+	"views": 0,
+	"deleted": false,
+	"revisions": {
+		"1": {
+			"tags": [
+				""
+			],
+			"name": "Fungus",
+			"comment": "Update Fungus",
+			"author": "",
+			"time": 1592835944,
+			"text_mime": "text/markdown",
+			"binary_mime": "",
+			"text_name": "1.markdown",
+			"binary_name": ""
+		}
+	}
+}

w/m/sys/main.css/9.css

@@ -14,12 +14,20 @@ body {
     padding: 12px 24px;
 }
 
+.msg {
+    background-color: #f4f4f4;
+    padding: 1rem;
+}
+.msg_hypha-does-not-exist {
+    border-radius: 1rem;
+}
+
 .shroom {
     margin: 0;
 }
 
 .shroom__button {
-    border-radius: 8px;
+    border-radius: 1rem;
     padding: 8px 16px 8px 0;
     border: none;
     background: #f0f2f4;
@@ -65,7 +73,7 @@ a:visited {
 }
 
 h1, h2, h3, h4, h5, h6 {
-    margin: 1em 0 0.25em;
+    margin: 0.5em 0 0.25em;
 }
 
 .page {
@@ -178,7 +186,7 @@ footer a, footer a:visited {
 
 .sidebar {
     padding: 16px 0;
-    border-radius: 8px;
+    border-radius: 1rem;
     background: #f4f4f4;
 }
 

w/templates/Hypha/view/404.html

@@ -0,0 +1,8 @@
+<div class="naviwrapper">
+	<article class="page">
+		<h1 class="page__title">{{ . }}</h1>
+		<p class="msg_hypha-does-not-exist msg">
+		The hypha you are trying to access does not exist yet. Why not <a href="?action=edit">create</a> it?
+		</p>
+	</article>
+</div>