Revert getTiddlerData() and add getTiddlerDataCached()

For backwards compatibility, we now explicitly request the cacheable
version of this method.

Fixes #1873

core/modules/commands/savelibrarytiddlers.js

@@ -43,7 +43,7 @@ Command.prototype.execute = function() {
 		basepath = this.params[2],
 		skinnyListTitle = this.params[3];
 	// Get the container tiddler as data
-	var containerData = self.commander.wiki.getTiddlerData(containerTitle,undefined);
+	var containerData = self.commander.wiki.getTiddlerDataCached(containerTitle,undefined);
 	if(!containerData) {
 		return "'" + containerTitle + "' is not a tiddler bundle";
 	}

core/modules/commands/unpackplugin.js

@@ -29,7 +29,7 @@ Command.prototype.execute = function() {
 	}
 	var self = this,
 		title = this.params[0],
-		pluginData = this.commander.wiki.getTiddlerData(title);
+		pluginData = this.commander.wiki.getTiddlerDataCached(title);
 	if(!pluginData) {
 		return "Plugin '" + title + "' not found";
 	}

core/modules/filters/indexes.js

@@ -18,7 +18,7 @@ Export our filter function
 exports.indexes = function(source,operator,options) {
 	var results = [];
 	source(function(tiddler,title) {
-		var data = options.wiki.getTiddlerData(title);
+		var data = options.wiki.getTiddlerDataCached(title);
 		if(data) {
 			$tw.utils.pushTop(results,Object.keys(data));
 		}

core/modules/filters/plugintiddlers.js

@@ -18,7 +18,7 @@ Export our filter function
 exports.plugintiddlers = function(source,operator,options) {
 	var results = [];
 	source(function(tiddler,title) {
-		var pluginInfo = options.wiki.getPluginInfo(title) || options.wiki.getTiddlerData(title,{tiddlers:[]});
+		var pluginInfo = options.wiki.getPluginInfo(title) || options.wiki.getTiddlerDataCached(title,{tiddlers:[]});
 		if(pluginInfo && pluginInfo.tiddlers) {
 			$tw.utils.each(pluginInfo.tiddlers,function(fields,title) {
 				results.push(title);

core/modules/storyviews/zoomin.js

@@ -18,7 +18,7 @@ var ZoominListView = function(listWidget) {
 	var self = this;
 	this.listWidget = listWidget;
 	// Get the index of the tiddler that is at the top of the history
-	var history = this.listWidget.wiki.getTiddlerData(this.listWidget.historyTitle,[]),
+	var history = this.listWidget.wiki.getTiddlerDataCached(this.listWidget.historyTitle,[]),
 		targetTiddler;
 	if(history.length > 0) {
 		targetTiddler = history[history.length-1].title;

core/modules/upgraders/themetweaks.js

@@ -44,7 +44,7 @@ exports.upgrade = function(wiki,titles,tiddlers) {
 		var mapping = MAPPINGS[title];
 		if(mapping) {
 			var tiddler = new $tw.Tiddler(tiddlers[title]),
-				tiddlerData = wiki.getTiddlerData(tiddler,{});
+				tiddlerData = wiki.getTiddlerDataCached(tiddler,{});
 			for(var index in mapping) {
 				var mappedTitle = mapping[index];
 				if(!tiddlers[mappedTitle] || tiddlers[mappedTitle].title !== mappedTitle) {

core/modules/utils/utils.js

@@ -171,6 +171,17 @@ exports.extendDeepCopy = function(object,extendedProperties) {
 	return result;
 };
 
+exports.deepFreeze = function deepFreeze(object) {
+	var property, key;
+	Object.freeze(object);
+	for(key in object) {
+		property = object[key];
+		if($tw.utils.hop(object,key) && (typeof property === "object") && !Object.isFrozen(property)) {
+			deepFreeze(property);
+		}
+	}
+};
+
 exports.slowInSlowOut = function(t) {
 	return (1 - ((Math.cos(t * Math.PI) + 1) / 2));
 };

core/modules/widgets/list.js

@@ -156,7 +156,7 @@ Handle any changes to the history list
 */
 ListWidget.prototype.handleHistoryChanges = function() {
 	// Get the history data
-	var newHistory = this.wiki.getTiddlerData(this.historyTitle,[]);
+	var newHistory = this.wiki.getTiddlerDataCached(this.historyTitle,[]);
 	// Ignore any entries of the history that match the previous history
 	var entry = 0;
 	while(entry < newHistory.length && entry < this.history.length && newHistory[entry].title === this.history[entry].title) {

core/modules/widgets/navigator.js

@@ -539,7 +539,7 @@ NavigatorWidget.prototype.handleImportTiddlersEvent = function(event) {
 NavigatorWidget.prototype.handlePerformImportEvent = function(event) {
 	var self = this,
 		importTiddler = this.wiki.getTiddler(event.param),
-		importData = this.wiki.getTiddlerData(event.param,{tiddlers: {}}),
+		importData = this.wiki.getTiddlerDataCached(event.param,{tiddlers: {}}),
 		importReport = [];
 	// Add the tiddlers to the store
 	importReport.push("The following tiddlers were imported:\n");

core/modules/wiki.js

@@ -577,7 +577,7 @@ exports.sortByList = function(array,listTitle) {
 };
 
 exports.getSubTiddler = function(title,subTiddlerTitle) {
-	var bundleInfo = this.getPluginInfo(title) || this.getTiddlerData(title);
+	var bundleInfo = this.getPluginInfo(title) || this.getTiddlerDataCached(title);
 	if(bundleInfo && bundleInfo.tiddlers) {
 		var subTiddler = bundleInfo.tiddlers[subTiddlerTitle];
 		if(subTiddler) {
@@ -613,6 +613,29 @@ Other types currently just return null.
 
 titleOrTiddler: string tiddler title or a tiddler object
 defaultData: default data to be returned if the tiddler is missing or doesn't contain data
+
+Note that the same value is returned for repeated calls for the same tiddler data. The value is frozen to prevent modification; otherwise modifications would be visible to all callers
+*/
+exports.getTiddlerDataCached = function(titleOrTiddler,defaultData) {
+	var self = this,
+		tiddler = titleOrTiddler;
+	if(!(tiddler instanceof $tw.Tiddler)) {
+		tiddler = this.getTiddler(tiddler);	
+	}
+	if(tiddler) {
+		return this.getCacheForTiddler(tiddler.fields.title,"data",function() {
+			// Return the frozen value
+			var value = self.getTiddlerData(tiddler.fields.title,defaultData);
+			$tw.utils.deepFreeze(value);
+			return value;
+		});
+	} else {
+		return defaultData;
+	}
+};
+
+/*
+Alternative, uncached version of getTiddlerDataCached(). The return value can be mutated freely and reused
 */
 exports.getTiddlerData = function(titleOrTiddler,defaultData) {
 	var tiddler = titleOrTiddler,
@@ -621,20 +644,18 @@ exports.getTiddlerData = function(titleOrTiddler,defaultData) {
 		tiddler = this.getTiddler(tiddler);	
 	}
 	if(tiddler && tiddler.fields.text) {
-		return this.getCacheForTiddler(tiddler.fields.title,"data",function() {
-			switch(tiddler.fields.type) {
-				case "application/json":
-					// JSON tiddler
-					try {
-						data = JSON.parse(tiddler.fields.text);
-					} catch(ex) {
-						return defaultData;
-					}
-					return data;
-				case "application/x-tiddler-dictionary":
-					return $tw.utils.parseFields(tiddler.fields.text);
-			}
-		});
+		switch(tiddler.fields.type) {
+			case "application/json":
+				// JSON tiddler
+				try {
+					data = JSON.parse(tiddler.fields.text);
+				} catch(ex) {
+					return defaultData;
+				}
+				return data;
+			case "application/x-tiddler-dictionary":
+				return $tw.utils.parseFields(tiddler.fields.text);
+		}
 	}
 	return defaultData;
 };