FEATURE: Add onLoad callback handler CMSLoadFunctions

git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/cms/branches/2.4@96440 467b73ca-7a2a-4603-9d3b-597d59a354a9

javascript/LeftAndMain_right.js

@@ -1,3 +1,41 @@
+/**
+ * CMSLoadFunctions provides the ability to have 'onLoad' functions for pages
+ * in the CMS.
+ * These callbacks will be executed when a page has been loaded after clicking
+ * on it in the left-hand Site Content Tree.
+ * The usual document.ready functions won't work in this case as the page data
+ * is loaded via AJAX.
+ *
+ * A function will not be added twice, even if add() is called twice.
+ *
+ * Usage:
+ *	CMSLoadFunctions.add(function(){ ... });
+ *
+ */
+CMSLoadFunctions = {
+	add: function(fn) {
+		if (!this.load_functions) {
+			this.load_functions = [];
+		}
+		if (!(fn in this.load_functions)) {
+			this.load_functions.push(fn);
+		}
+	},
+
+	run: function() {
+		if (!this.load_functions) {
+			this.load_functions = [];
+			return;
+		}
+		for(var i=0; i < this.load_functions.length; i++) {
+			var fn = this.load_functions[i];
+			if(typeof(fn) == 'function') {
+				fn();
+			}
+		}
+	}
+};
+
 
 CMSForm = Class.extend('ChangeTracker').extend('Observable');
 CMSForm.prototype = {
@@ -263,6 +301,7 @@ CMSRightForm.prototype = {
 			statusMessage('');
 		}
 
+		CMSLoadFunctions.run();
 		// must wait until the javascript has finished
 		document.body.style.cursor = 'default';