Transclude widget: refresh selectively when needed (#5736)

* Transclude widget: only refresh when transcluded text reference has changed, includes tests

* Refactor wiki.parseTextReference so it is re-usable for getting the parser info

* Re-arrange methods in wiki.js to improve diff readability

core/modules/widgets/transclude.js

@@ -60,6 +60,8 @@ TranscludeWidget.prototype.execute = function() {
 							subTiddler: this.transcludeSubTiddler
 						}),
 		parseTreeNodes = parser ? parser.tree : this.parseTreeNode.children;
+	this.sourceText = parser ? parser.source : null;
+	this.parserType = parser? parser.type : null;
 	// Set context variables for recursion detection
 	var recursionMarker = this.makeRecursionMarker();
 	if(this.recursionMarker === "yes") {
@@ -98,12 +100,17 @@ TranscludeWidget.prototype.makeRecursionMarker = function() {
 	return output.join("");
 };
 
+TranscludeWidget.prototype.parserNeedsRefresh = function() {
+	var parserInfo = this.wiki.getTextReferenceParserInfo(this.transcludeTitle,this.transcludeField,this.transcludeIndex,{subTiddler:this.transcludeSubTiddler});
+	return (this.sourceText === undefined || parserInfo.sourceText !== this.sourceText || parserInfo.parserType !== this.parserType)
+};
+
 /*
 Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
 */
 TranscludeWidget.prototype.refresh = function(changedTiddlers) {
 	var changedAttributes = this.computeAttributes();
-	if(changedAttributes.tiddler || changedAttributes.field || changedAttributes.index || changedTiddlers[this.transcludeTitle]) {
+	if(($tw.utils.count(changedAttributes) > 0) || (changedTiddlers[this.transcludeTitle] && this.parserNeedsRefresh())) {
 		this.refreshSelf();
 		return true;
 	} else {

core/modules/wiki.js

@@ -937,41 +937,57 @@ exports.parseTiddler = function(title,options) {
 };
 
 exports.parseTextReference = function(title,field,index,options) {
-	var tiddler,text;
-	if(options.subTiddler) {
-		tiddler = this.getSubTiddler(title,options.subTiddler);
-	} else {
+	var tiddler,
+		text,
+		parserInfo;
+	if(!options.subTiddler) {
 		tiddler = this.getTiddler(title);
 		if(field === "text" || (!field && !index)) {
 			this.getTiddlerText(title); // Force the tiddler to be lazily loaded
 			return this.parseTiddler(title,options);
 		}
 	} 
-	if(field === "text" || (!field && !index)) {
-		if(tiddler && tiddler.fields) {
-			return this.parseText(tiddler.fields.type,tiddler.fields.text,options);
+	parserInfo = this.getTextReferenceParserInfo(title,field,index,options);
+	if(parserInfo.sourceText !== null) {
+		return this.parseText(parserInfo.parserType,parserInfo.sourceText,options);
 	} else {
 		return null;
 	}
+};
+
+exports.getTextReferenceParserInfo = function(title,field,index,options) {
+	var tiddler,
+		parserInfo = {
+			sourceText : null,
+			parserType : "text/vnd.tiddlywiki"
+		};
+	if(options.subTiddler) {
+		tiddler = this.getSubTiddler(title,options.subTiddler);
+	} else {
+		tiddler = this.getTiddler(title);
+	}
+	if(field === "text" || (!field && !index)) {
+		if(tiddler && tiddler.fields) {
+			parserInfo.sourceText = tiddler.fields.text || "";
+			if(tiddler.fields.type) {
+				parserInfo.parserType = tiddler.fields.type;
+			}
+		}
 	} else if(field) {
 		if(field === "title") {
-			text = title;
-		} else {
-			if(!tiddler || !tiddler.hasField(field)) {
-				return null;
+			parserInfo.sourceText = title;
+		} else if(tiddler && tiddler.fields) {
+			parserInfo.sourceText = tiddler.fields[field] ? tiddler.fields[field].toString() : null;
 		}
-			text = tiddler.fields[field];
-		}
-		return this.parseText("text/vnd.tiddlywiki",text.toString(),options);
 	} else if(index) {
 		this.getTiddlerText(title); // Force the tiddler to be lazily loaded
-		text = this.extractTiddlerDataItem(tiddler,index,undefined);
-		if(text === undefined) {
-			return null;
+		parserInfo.sourceText = this.extractTiddlerDataItem(tiddler,index,null);
 	}
-		return this.parseText("text/vnd.tiddlywiki",text,options);
+	if(parserInfo.sourceText === null) {
+		parserInfo.parserType = null;
+	}
+	return parserInfo;
 }
-};
 
 /*
 Make a widget tree for a parse tree

editions/test/tiddlers/tests/test-parsetextreference.js

@@ -0,0 +1,123 @@
+/*\
+title: test-parsetextreference.js
+type: application/javascript
+tags: [[$:/tags/test-spec]]
+
+Tests for source attribute in parser returned from wiki.parseTextReference
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+describe("Wiki.parseTextReference tests", function() {
+
+	// Create a wiki
+	var wiki = new $tw.Wiki();
+	wiki.addTiddler({
+		title: "TiddlerOne",
+		text: "The quick brown fox in $:/TiddlerTwo",
+		tags: ["one"],
+		authors: "Joe Bloggs",
+		modifier: "JoeBloggs",
+		modified: "201304152222"});
+	wiki.addTiddler({
+		title: "$:/TiddlerTwo",
+		tags: ["two"],
+		authors: "[[John Doe]]",
+		modifier: "John",
+		modified: "201304152211"});
+	wiki.addTiddler({
+		title: "Tiddler Three",
+		text: '{"oct":31,"nov":30,"dec":31}',
+		tags: ["one","two"],
+		type: "application/json",
+		modifier: "John",
+		modified: "201304162202"});
+	wiki.addTiddler({
+		title: "TiddlerFour",
+		text: "The quick brown fox in $:/TiddlerTwo",
+		tags: ["one"],
+		type: "text/vnd.tiddlywiki",
+		authors: "Joe Bloggs",
+		modifier: "JoeBloggs",
+		modified: "201304152222"});
+	// Add a plugin containing some shadow tiddlers
+	var shadowTiddlers = {
+		tiddlers: {
+			"$:/TiddlerFive": {
+				title: "$:/TiddlerFive",
+				text: "Everything in federation",
+				tags: ["two"]
+			},
+			"TiddlerSix": {
+				title: "TiddlerSix",
+				text: "Missing inaction from TiddlerOne",
+				filter: "[[one]] [[a a]] [subfilter{hasList!!list}]",
+				tags: []
+			},
+			"TiddlerSeventh": {
+				title: "TiddlerSeventh",
+				text: "",
+				list: "TiddlerOne [[Tiddler Three]] [[a fourth tiddler]] MissingTiddler",
+				tags: ["one"]
+			},
+			"Tiddler8": {
+				title: "Tiddler8",
+				text: "Tidd",
+				tags: ["one"],
+				"test-field": "JoeBloggs"
+			}
+		}
+	};
+	wiki.addTiddler({
+		title: "$:/ShadowPlugin",
+		text: JSON.stringify(shadowTiddlers),
+		"plugin-type": "plugin",
+		type: "application/json"});
+	wiki.addTiddler({
+		title: "TiddlerNine",
+		text: "this is plain text",
+		type: "text/plain"
+	});
+
+	// Define a parsing shortcut for souce attribute of parser returned by wiki.parseTextReference
+	var parseAndGetSource = function(title,field,index,subTiddler) {
+		var parser = wiki.parseTextReference(title,field,index,{subTiddler: subTiddler});
+		return parser ? parser.source : null;
+	};
+
+	it("should parse text references and return correct source attribute", function(){
+		// Existing tiddler with a text field, no field argument specified
+		expect(parseAndGetSource("TiddlerOne")).toEqual("The quick brown fox in $:/TiddlerTwo");
+		// Existing tiddler with a text field, field argument specified as text
+		expect(parseAndGetSource("TiddlerOne","text")).toEqual("The quick brown fox in $:/TiddlerTwo");
+		// Existing tiddler with no text field
+		expect(parseAndGetSource("$:/TiddlerTwo")).toEqual("");
+		// Existing tiddler, field argument specified as authors
+		expect(parseAndGetSource("TiddlerOne","authors")).toEqual("Joe Bloggs");
+		// Non-existent tiddler, no field argument
+		expect(parseAndGetSource("MissingTiddler")).toEqual(null);
+		// Non-existent tiddler, field argument
+		expect(parseAndGetSource("MissingTiddler","missing-field")).toEqual(null);
+		// Non-existent tiddler, index specified
+		expect(parseAndGetSource("MissingTiddler",null,"missing-index")).toEqual(null);
+		// Existing tiddler with non existent field
+		expect(parseAndGetSource("TiddlerOne","missing-field")).toEqual(null);
+		// Data tiddler with index specified
+		expect(parseAndGetSource("Tiddler Three",null,"oct")).toEqual("31");
+		// Existing tiddler with a text field, type set to vnd.tiddlywiki
+		expect(parseAndGetSource("TiddlerFour")).toEqual("The quick brown fox in $:/TiddlerTwo");
+		// Existing subtiddler of a plugin
+		expect(parseAndGetSource("$:/ShadowPlugin","text",null,"Tiddler8")).toEqual("Tidd");
+		// Non-existent subtiddler of a plugin
+		expect(parseAndGetSource("$:/ShadowPlugin","text",null,"MyMissingTiddler")).toEqual(null);
+		// Plain text tiddler
+		expect(parseAndGetSource("TiddlerNine")).toEqual(undefined);
+	});
+
+});
+
+})();