Docs updates

editions/tw5.com/tiddlers/widgets/ErrorWidget.tid

@@ -0,0 +1,17 @@
+caption: error
+created: 20220909111836951
+modified: 20220909111836951
+tags: Widgets
+title: ErrorWidget
+type: text/vnd.tiddlywiki
+
+<<.from-version "5.3.0">> The <<.wlink ErrorWidget>> widget is used by the core to display error messages such as the recursion errors reported by the <<.wlink TranscludeWidget>> widget.
+
+The <<.wlink ErrorWidget>> does not provide any useful functionality to end users. It is only required by the core for technical reasons.
+
+! Content and Attributes
+
+The content of the <<.wlink ErrorWidget>> widget is ignored.
+
+|!Attribute |!Description |
+|$message |The error message |

editions/tw5.com/tiddlers/widgets/FillWidget.tid

@@ -0,0 +1,19 @@
+caption: fill
+created: 20220909111836951
+modified: 20220909111836951
+tags: Widgets
+title: FillWidget
+type: text/vnd.tiddlywiki
+
+! Introduction
+
+<<.from-version "5.3.0">> The <<.wlink FillWidget>> widget is used within a <<.wlink TranscludeWidget>> widget to specify the content that should be copied to the named "slot". Slots are defined by the <<.wlink SlotWidget>> widget within the transcluded content.
+
+See the <<.wlink TranscludeWidget>> widget for details.
+
+! Attributes
+
+The content of the <<.wlink FillWidget>> widget is used as the content to be passed to the transclusion.
+
+|!Attribute |!Description |
+|$name |The name of the slot to be filled |

editions/tw5.com/tiddlers/widgets/MacroCallWidget.tid

@@ -1,48 +1,29 @@
 caption: macrocall
 created: 20131024141900000
-modified: 20220122193731433
+modified: 20220909111836951
 tags: Widgets
 title: MacroCallWidget
 type: text/vnd.tiddlywiki
 
-! Introduction
+<<.from-version "5.3.0">> The <<.wlink MacroCallWidget>> widget is now deprecated. While it will continue to work, users are advised to use the <<.wlink TranscludeWidget>> widget, converting the `$name` attribute to `$variable`.
 
-The macro call widget provides a more flexible alternative syntax for invoking macros compared to the usual `<<macroname>>` syntax documented in [[Macros in WikiText]].
-
-For example, a macro called `italicise` that takes a single parameter called `text` would usually be invoked like this:
+For example,
 
 ```
-<<italicise "Text to be made into italics">>
-<<italicise text:"Text to be made into italics">>
+<$macrocall $name="my-macro" my-parameter="Elephant"/>
 ```
 
-The same macro can be invoked using the macro call widget like this:
+should be changed to:
 
 ```
-<$macrocall $name="italicise" text="Text to be made into italics"/>
-<$macrocall $name="italicise" text={{Title of tiddler containing text to be italicised}}/>
-<$macrocall $name="italicise" text=<<textMaker "Another macro to generate the text to be italicised">>/>
+<$transclude $variable="my-macro" my-parameter="Elephant"/>
 ```
 
-The advantages of the widget formulation are:
-
-* Macro parameters are specified as widget attributes, thus allowing indirection via `{{title!!field}}`, `<<macroname>>` or `{{{filter}}}`
-* The output format can be chosen from several options:
-** `text/html` wikifies the result of the macro
-** `text/plain` wikifies the result of the macro and then extracts the plain text characters (ie. ignoring HTML tags)
-** <<.from-version "5.1.23">> `text/raw` returns the result of the macro, without wikification
-
-You can see several examples of the macro call widget within the core:
-
-* Listing module information: [[$:/snippets/modules]]
-* Listing field information: [[$:/snippets/allfields]]
-* Generating `data:` URIs: [[$:/themes/tiddlywiki/starlight/styles.tid]]
-
-See also [[WikiText parser mode: macro examples]]
+Internally, the <<.wlink MacroCallWidget>> widget is implemented via the <<.wlink TranscludeWidget>> widget.
 
 ! Content and Attributes
 
-The content of the `<$macrocall>` widget is ignored.
+The content of the <<.wlink MacroCallWidget>> widget is ignored.
 
 |!Attribute |!Description |
 |$name |Name of the macro to invoke |

editions/tw5.com/tiddlers/widgets/SetWidget.tid

@@ -1,6 +1,6 @@
 caption: set
 created: 20131115182700000
-modified: 20220523075522407
+modified: 20220909111836951
 tags: Widgets
 title: SetWidget
 type: text/vnd.tiddlywiki
@@ -23,6 +23,7 @@ The content of the `<$set>` widget is the scope for the value assigned to the va
 |filter |An optional filter to be evaluated and assigned to the variable (see "Filtered List Variable Assignment" below). The variable can be used with the <<.olink enlist>> operator |
 |select |<<.from-version "5.1.14">> An optional zero-based index of the item to return from the filter output (see below) |
 |emptyValue |The value to assign to the variable if the specified value is missing or empty (see below) |
+|conditional |<<.from-version "5.3.0">> If set to "yes" then the assignment only occurs if the variable does not already have a value (defaults to "no") |
 
 <<.tip """If the value of your variable is enclosed in double square brackets this might indicate that you are returning a list of values from the filter. To use a single title from the filter output without the double square brackets see ''Filtered Item Variable Assignment'' below.""">>
 

editions/tw5.com/tiddlers/widgets/SlotWidget.tid

@@ -0,0 +1,19 @@
+caption: slot
+created: 20220909111836951
+modified: 20220909111836951
+tags: Widgets
+title: SlotWidget
+type: text/vnd.tiddlywiki
+
+! Introduction
+
+<<.from-version "5.3.0">> The <<.wlink SlotWidget>> widget is used within transcluded content to mark "slots" that the transcluding widget can fill with the <<.wlink FillWidget>> widget.
+
+See the <<.wlink TranscludeWidget>> widget for details.
+
+! Attributes
+
+The content of the <<.wlink SlotWidget>> widget is used as a fallback for the slot content if the corresponding <<.wlink FillWidget>> widget is not found.
+
+|!Attribute |!Description |
+|$name |The name of the slot being defined |