Release

Release

ckeditor/core/scriptloader.js

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+/**
+ * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or http://ckeditor.com/license
+ */
+
+/**
+ * @fileOverview Defines the {@link CKEDITOR.scriptLoader} object, used to load scripts
+ *		asynchronously.
+ */
+
+/**
+ * Load scripts asynchronously.
+ *
+ * @class
+ * @singleton
+ */
+CKEDITOR.scriptLoader = ( function() {
+	var uniqueScripts = {},
+		waitingList = {};
+
+	return {
+		/**
+		 * Loads one or more external script checking if not already loaded
+		 * previously by this function.
+		 *
+		 *		CKEDITOR.scriptLoader.load( '/myscript.js' );
+		 *
+		 *		CKEDITOR.scriptLoader.load( '/myscript.js', function( success ) {
+		 *			// Alerts true if the script has been properly loaded.
+		 *			// HTTP error 404 should return false.
+		 *			alert( success );
+		 *		} );
+		 *
+		 *		CKEDITOR.scriptLoader.load( [ '/myscript1.js', '/myscript2.js' ], function( completed, failed ) {
+		 *			alert( 'Number of scripts loaded: ' + completed.length );
+		 *			alert( 'Number of failures: ' + failed.length );
+		 *		} );
+		 *
+		 * @param {String/Array} scriptUrl One or more URLs pointing to the
+		 * scripts to be loaded.
+		 * @param {Function} [callback] A function to be called when the script
+		 * is loaded and executed. If a string is passed to `scriptUrl`, a
+		 * boolean parameter is passed to the callback, indicating the
+		 * success of the load. If an array is passed instead, two arrays
+		 * parameters are passed to the callback - the first contains the
+		 * URLs that have been properly loaded and the second the failed ones.
+		 * @param {Object} [scope] The scope (`this` reference) to be used for
+		 * the callback call. Defaults to {@link CKEDITOR}.
+		 * @param {Boolean} [showBusy] Changes the cursor of the document while
+		 * the script is loaded.
+		 */
+		load: function( scriptUrl, callback, scope, showBusy ) {
+			var isString = ( typeof scriptUrl == 'string' );
+
+			if ( isString )
+				scriptUrl = [ scriptUrl ];
+
+			if ( !scope )
+				scope = CKEDITOR;
+
+			var scriptCount = scriptUrl.length,
+				completed = [],
+				failed = [];
+
+			var doCallback = function( success ) {
+					if ( callback ) {
+						if ( isString )
+							callback.call( scope, success );
+						else
+							callback.call( scope, completed, failed );
+					}
+				};
+
+			if ( scriptCount === 0 ) {
+				doCallback( true );
+				return;
+			}
+
+			var checkLoaded = function( url, success ) {
+					( success ? completed : failed ).push( url );
+
+					if ( --scriptCount <= 0 ) {
+						showBusy && CKEDITOR.document.getDocumentElement().removeStyle( 'cursor' );
+						doCallback( success );
+					}
+				};
+
+			var onLoad = function( url, success ) {
+					// Mark this script as loaded.
+					uniqueScripts[ url ] = 1;
+
+					// Get the list of callback checks waiting for this file.
+					var waitingInfo = waitingList[ url ];
+					delete waitingList[ url ];
+
+					// Check all callbacks waiting for this file.
+					for ( var i = 0; i < waitingInfo.length; i++ )
+						waitingInfo[ i ]( url, success );
+				};
+
+			var loadScript = function( url ) {
+					if ( uniqueScripts[ url ] ) {
+						checkLoaded( url, true );
+						return;
+					}
+
+					var waitingInfo = waitingList[ url ] || ( waitingList[ url ] = [] );
+					waitingInfo.push( checkLoaded );
+
+					// Load it only for the first request.
+					if ( waitingInfo.length > 1 )
+						return;
+
+					// Create the <script> element.
+					var script = new CKEDITOR.dom.element( 'script' );
+					script.setAttributes( {
+						type: 'text/javascript',
+						src: url
+					} );
+
+					if ( callback ) {
+						// The onload or onerror event does not fire in IE8 and IE9 Quirks Mode (#14849).
+						if ( CKEDITOR.env.ie && ( CKEDITOR.env.version <= 8 || CKEDITOR.env.ie9Compat ) ) {
+							script.$.onreadystatechange = function() {
+								if ( script.$.readyState == 'loaded' || script.$.readyState == 'complete' ) {
+									script.$.onreadystatechange = null;
+									onLoad( url, true );
+								}
+							};
+						} else {
+							script.$.onload = function() {
+								// Some browsers, such as Safari, may call the onLoad function
+								// immediately. Which will break the loading sequence. (#3661)
+								setTimeout( function() {
+									onLoad( url, true );
+								}, 0 );
+							};
+
+							script.$.onerror = function() {
+								onLoad( url, false );
+							};
+						}
+					}
+
+					// Append it to <head>.
+					script.appendTo( CKEDITOR.document.getHead() );
+
+					CKEDITOR.fire( 'download', url ); // %REMOVE_LINE%
+				};
+
+			showBusy && CKEDITOR.document.getDocumentElement().setStyle( 'cursor', 'wait' );
+			for ( var i = 0; i < scriptCount; i++ ) {
+				loadScript( scriptUrl[ i ] );
+			}
+		},
+
+		/**
+		 * Loads a script in a queue, so only one is loaded at the same time.
+		 *
+		 * @since 4.1.2
+		 * @param {String} scriptUrl URL pointing to the script to be loaded.
+		 * @param {Function} [callback] A function to be called when the script
+		 * is loaded and executed. A boolean parameter is passed to the callback,
+		 * indicating the success of the load.
+		 *
+		 * @see CKEDITOR.scriptLoader#load
+		 */
+		queue: ( function() {
+			var pending = [];
+
+			// Loads the very first script from queue and removes it.
+			function loadNext() {
+				var script;
+
+				if ( ( script = pending[ 0 ] ) )
+					this.load( script.scriptUrl, script.callback, CKEDITOR, 0 );
+			}
+
+			return function( scriptUrl, callback ) {
+				var that = this;
+
+				// This callback calls the standard callback for the script
+				// and loads the very next script from pending list.
+				function callbackWrapper() {
+					callback && callback.apply( this, arguments );
+
+					// Removed the just loaded script from the queue.
+					pending.shift();
+
+					loadNext.call( that );
+				}
+
+				// Let's add this script to the queue
+				pending.push( { scriptUrl: scriptUrl, callback: callbackWrapper } );
+
+				// If the queue was empty, then start loading.
+				if ( pending.length == 1 )
+					loadNext.call( this );
+			};
+		} )()
+	};
+} )();