From a2caf46b1e292a97fecb0bbb7530d1e9d599c642 Mon Sep 17 00:00:00 2001
From: Jeremy Ruston <jeremy@osmosoft.com>
Date: Sun, 22 Jul 2012 22:03:06 +0100
Subject: [PATCH] Added new wiki methods for reading and writing a toddler as
 data

---
 core/modules/macros/navigator.js   | 16 ++++-----------
 core/modules/macros/story/story.js | 14 ++-----------
 core/modules/startup.js            |  4 ++--
 core/modules/wiki.js               | 32 +++++++++++++++++++++++++++++-
 4 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/core/modules/macros/navigator.js b/core/modules/macros/navigator.js
index f4b866491..e29d221af 100644
--- a/core/modules/macros/navigator.js
+++ b/core/modules/macros/navigator.js
@@ -22,30 +22,22 @@ exports.info = {
 };
 
 exports.getStory = function() {
-	var storyTiddler = this.wiki.getTiddler(this.params.story);
-	this.story = {tiddlers: []};
-	if(storyTiddler && $tw.utils.hop(storyTiddler.fields,"text")) {
-		this.story = JSON.parse(storyTiddler.fields.text);
-	}
+	this.story = this.wiki.getTiddlerData(this.params.story,{tiddlers: []});
 };
 
 exports.saveStory = function() {
 	if(this.hasParameter("story")) {
-		this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getTiddler(this.params.story),{title: this.params.story, text: JSON.stringify(this.story)}));
+		this.wiki.setTiddlerData(this.params.story,this.story);
 	}
 };
 
 exports.getHistory = function() {
-	var historyTiddler = this.wiki.getTiddler(this.params.history);
-	this.history = {stack: []};
-	if(historyTiddler && $tw.utils.hop(historyTiddler.fields,"text")) {
-		this.history = JSON.parse(historyTiddler.fields.text);
-	}
+	this.history = this.wiki.getTiddlerData(this.params.history,{stack: []});
 };
 
 exports.saveHistory = function() {
 	if(this.hasParameter("history")) {
-		this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getTiddler(this.params.history),{title: this.params.history, text: JSON.stringify(this.history)}));
+		this.wiki.setTiddlerData(this.params.history,this.history);
 	}
 };
 
diff --git a/core/modules/macros/story/story.js b/core/modules/macros/story/story.js
index c179230f6..d8a31bfa1 100644
--- a/core/modules/macros/story/story.js
+++ b/core/modules/macros/story/story.js
@@ -52,21 +52,11 @@ exports.info = {
 Get the data from the JSON story tiddler
 */
 exports.getStory = function() {
-	var storyTiddler = this.wiki.getTiddler(this.params.story);
-	this.story = {
-		tiddlers: []
-	};
-	if(storyTiddler && $tw.utils.hop(storyTiddler.fields,"text")) {
-		this.story = JSON.parse(storyTiddler.fields.text);
-	}
+	this.story = this.wiki.getTiddlerData(this.params.story,{tiddlers: []});
 };
 
 exports.getHistory = function() {
-	var historyTiddler = this.wiki.getTiddler(this.params.history);
-	this.history = {stack: []};
-	if(historyTiddler && $tw.utils.hop(historyTiddler.fields,"text")) {
-		this.history = JSON.parse(historyTiddler.fields.text);
-	}
+	this.history = this.wiki.getTiddlerData(this.params.history,{stack: []});
 };
 
 exports.getViewTemplate = function() {
diff --git a/core/modules/startup.js b/core/modules/startup.js
index e6daa234f..9a15d3dd6 100644
--- a/core/modules/startup.js
+++ b/core/modules/startup.js
@@ -75,8 +75,8 @@ exports.startup = function() {
 			story.tiddlers[t] = {title: defaultTiddlers[t]};
 			history.stack[defaultTiddlers.length - t - 1] = {title: defaultTiddlers[t], fromTitle: defaultTiddlers[t+1]};
 		}
-		$tw.wiki.addTiddler(new $tw.Tiddler({title: storyTitle,text: JSON.stringify(story)}));
-		$tw.wiki.addTiddler(new $tw.Tiddler({title: historyTitle,text: JSON.stringify(history)}));
+		$tw.wiki.addTiddler(new $tw.Tiddler({title: storyTitle,type: "application/json", text: JSON.stringify(story)}));
+		$tw.wiki.addTiddler(new $tw.Tiddler({title: historyTitle,type: "application/json", text: JSON.stringify(history)}));
 		// If we're being viewed on a data: URI then give instructions for how to save
 		if(document.location.protocol === "data:") {
 			var event = document.createEvent("Event");
diff --git a/core/modules/wiki.js b/core/modules/wiki.js
index b92ec8404..2917a18de 100644
--- a/core/modules/wiki.js
+++ b/core/modules/wiki.js
@@ -317,6 +317,36 @@ exports.getTiddlersWithTag = function(tag) {
 	return titles;
 };
 
+/*
+Get a tiddlers content as a JavaScript object. How this is done depends on the type of the tiddler:
+
+application/json: the tiddler JSON is parsed into an object
+
+Other types currently just return null.
+*/
+exports.getTiddlerData = function(title,defaultData) {
+	var tiddler = this.tiddlers[title],
+		data;
+	if(tiddler && tiddler.fields.text && tiddler.fields.type === "application/json") {
+		// JSON tiddler
+		try {
+			data = JSON.parse(tiddler.fields.text);
+		} catch(ex) {
+			return defaultData;
+		}
+		return data;
+	}
+	return defaultData;
+};
+
+/*
+Set a tiddlers content to a JavaScript object. Currently this is done by setting the tiddler's type to "application/json" and setting the text to the JSON text of the data.
+*/
+exports.setTiddlerData = function(title,data) {
+	var tiddler = this.getTiddler(title);
+	this.addTiddler(new $tw.Tiddler(tiddler,{title: title, type: "application/json", text: JSON.stringify(data)}));
+};
+
 // Return the named cache object for a tiddler. If the cache doesn't exist then the initializer function is invoked to create it
 exports.getCacheForTiddler = function(title,cacheName,initializer) {
 	this.caches = this.caches || {};
@@ -398,7 +428,7 @@ Parse text in a specified format and render it into another format
 	outputType: content type for the output
 	textType: content type of the input text
 	text: input text
-	options: see below
+	options: see wiki.parseText()
 Options are:
 	defaultType: Default MIME type to use if the specified one is unknown
 */