/*!
 * Ext JS Library 3.2.1
 * Copyright(c) 2006-2010 Ext JS, Inc.
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/** * @class Ext.Loader * @singleton * Simple class to help load JavaScript files on demand */ Ext.Loader = Ext.apply({}, {
/** * Loads a given set of .js files. Calls the callback function when all files have been loaded * Set preserveOrder to true to ensure non-parallel loading of files if load order is important * @param {Array} fileList Array of all files to load * @param {Function} callback Callback to call after all files have been loaded * @param {Object} scope The scope to call the callback in * @param {Boolean} preserveOrder True to make files load in serial, one after the other (defaults to false) */ load: function(fileList, callback, scope, preserveOrder) { var scope = scope || this, head = document.getElementsByTagName("head")[0], fragment = document.createDocumentFragment(), numFiles = fileList.length, loadedFiles = 0, me = this;
/** * Loads a particular file from the fileList by index. This is used when preserving order */ var loadFileIndex = function(index) { head.appendChild( me.buildScriptTag(fileList[index], onFileLoaded) ); };
/** * Callback function which is called after each file has been loaded. This calls the callback * passed to load once the final file in the fileList has been loaded */ var onFileLoaded = function() { loadedFiles ++; //if this was the last file, call the callback, otherwise load the next file if (numFiles == loadedFiles && typeof callback == 'function') { callback.call(scope); } else { if (preserveOrder === true) { loadFileIndex(loadedFiles); } } }; if (preserveOrder === true) { loadFileIndex.call(this, 0); } else { //load each file (most browsers will do this in parallel) Ext.each(fileList, function(file, index) { fragment.appendChild( this.buildScriptTag(file, onFileLoaded) ); }, this); head.appendChild(fragment); } }, /** * @private * Creates and returns a script tag, but does not place it into the document. If a callback function * is passed, this is called when the script has been loaded * @param {String} filename The name of the file to create a script tag for * @param {Function} callback Optional callback, which is called when the script has been loaded * @return {Element} The new script ta */ buildScriptTag: function(filename, callback) { var script = document.createElement('script'); script.type = "text/javascript"; script.src = filename; //IE has a different way of handling