From 80ee5adb148d7220474096a0e80da05148ca7323 Mon Sep 17 00:00:00 2001
From: "jeremy@jermolene.com" <jeremy@jermolene.com>
Date: Fri, 19 Mar 2021 15:37:59 +0000
Subject: [PATCH] Extend transclude widget to optionally set variables

Partially fixes #5199
---
 core/modules/widgets/transclude.js            | 11 +++++-
 core/modules/widgets/widget.js                | 35 +++++++++++++++++--
 .../tiddlers/widgets/TranscludeWidget.tid     |  3 +-
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/core/modules/widgets/transclude.js b/core/modules/widgets/transclude.js
index 1af7f9c42..c57579919 100755
--- a/core/modules/widgets/transclude.js
+++ b/core/modules/widgets/transclude.js
@@ -75,8 +75,17 @@ TranscludeWidget.prototype.execute = function() {
 			]}];
 		}
 	}
+	// Assign any variables set via attributes starting with $
+	var variables = Object.create(null);
+	$tw.utils.each(this.attributes,function(attribute,name) {
+		if(name.charAt(0) === "$") {
+			variables[name.substr(1)] = attribute;
+		}
+	});
 	// Construct the child widgets
-	this.makeChildWidgets(parseTreeNodes);
+	this.makeChildWidgets(parseTreeNodes,{
+		variables: variables
+	});
 };
 
 /*
diff --git a/core/modules/widgets/widget.js b/core/modules/widgets/widget.js
index 1925bfe00..50405c19c 100755
--- a/core/modules/widgets/widget.js
+++ b/core/modules/widgets/widget.js
@@ -333,9 +333,22 @@ Widget.prototype.assignAttributes = function(domNode,options) {
 /*
 Make child widgets correspondng to specified parseTreeNodes
 */
-Widget.prototype.makeChildWidgets = function(parseTreeNodes) {
+Widget.prototype.makeChildWidgets = function(parseTreeNodes,options) {
+	options = options || {};
 	this.children = [];
 	var self = this;
+	// Create set variable widgets for each variable
+	$tw.utils.each(options.variables,function(value,name) {
+		var setVariableWidget = {
+			type: "set",
+			attributes: {
+				name: {type: "string", value: name},
+				value: {type: "string", value: value}
+			},
+			children: parseTreeNodes
+		};
+		parseTreeNodes = [setVariableWidget];
+	});
 	$tw.utils.each(parseTreeNodes || (this.parseTreeNode && this.parseTreeNode.children),function(childNode) {
 		self.children.push(self.makeChildWidget(childNode));
 	});
@@ -343,16 +356,32 @@ Widget.prototype.makeChildWidgets = function(parseTreeNodes) {
 
 /*
 Construct the widget object for a parse tree node
+options include:
+	variables: optional hashmap of variables to wrap around the widget
 */
-Widget.prototype.makeChildWidget = function(parseTreeNode) {
+Widget.prototype.makeChildWidget = function(parseTreeNode,options) {
+	options = options || {};
 	var WidgetClass = this.widgetClasses[parseTreeNode.type];
 	if(!WidgetClass) {
 		WidgetClass = this.widgetClasses.text;
 		parseTreeNode = {type: "text", text: "Undefined widget '" + parseTreeNode.type + "'"};
 	}
+	// Create set variable widgets for each variable
+	$tw.utils.each(options.variables,function(value,name) {
+		var setVariableWidget = {
+			type: "set",
+			attributes: {
+				name: {type: "string", value: name},
+				value: {type: "string", value: value}
+			},
+			children: [
+				parseTreeNode
+			]
+		};
+		parseTreeNode = setVariableWidget;
+	});
 	return new WidgetClass(parseTreeNode,{
 		wiki: this.wiki,
-		variables: {},
 		parentWidget: this,
 		document: this.document
 	});
diff --git a/editions/tw5.com/tiddlers/widgets/TranscludeWidget.tid b/editions/tw5.com/tiddlers/widgets/TranscludeWidget.tid
index 0501d7091..c28e44432 100644
--- a/editions/tw5.com/tiddlers/widgets/TranscludeWidget.tid
+++ b/editions/tw5.com/tiddlers/widgets/TranscludeWidget.tid
@@ -1,5 +1,5 @@
 created: 20130824142500000
-modified: 20140717175900970
+modified: 20210319150601867
 tags: Widgets
 title: TranscludeWidget
 type: text/vnd.tiddlywiki
@@ -17,6 +17,7 @@ The TranscludeWidget dynamically imports content from another tiddler.
 |index |The index of a property in a [[DataTiddler|DataTiddlers]] |
 |subtiddler |Optional SubTiddler title when the target tiddler is a [[plugin|Plugins]] (see below) |
 |mode |Override the default parsing mode for the transcluded text to "block" or "inline" |
+|//(attributes starting with $)// |<<.from-version "5.1.24">> The $ is removed from each attribute name to specify a variable name that is assigned the specified value for the scope of the transclusion |
 
 The TranscludeWidget treats any contained content as a fallback if the target of the transclusion is not defined (ie a missing tiddler or a missing field).