_source/core/scriptloader.js

   1 /*\r
   2 Copyright (c) 2003-2009, CKSource - Frederico Knabben. All rights reserved.\r
   3 For licensing, see LICENSE.html or http://ckeditor.com/license\r
   4 */\r
   5 \r
   6 /**\r
   7  * @fileOverview Defines the {@link CKEDITOR.scriptLoader} object, used to load scripts\r
   8  *              asynchronously.\r
   9  */\r
  10 \r
  11 /**\r
  12  * Load scripts asynchronously.\r
  13  * @namespace\r
  14  * @example\r
  15  */\r
  16 CKEDITOR.scriptLoader = (function()\r
  17 {\r
  18         var uniqueScripts = {};\r
  19         var waitingList = {};\r
  20 \r
  21         return /** @lends CKEDITOR.scriptLoader */ {\r
  22                 /**\r
  23                  * Loads one or more external script checking if not already loaded\r
  24                  * previously by this function.\r
  25                  * @param {String|Array} scriptUrl One or more URLs pointing to the\r
  26                  *              scripts to be loaded.\r
  27                  * @param {Function} [callback] A function to be called when the script\r
  28                  *              is loaded and executed. If a string is passed to "scriptUrl", a\r
  29                  *              boolean parameter is passed to the callback, indicating the\r
  30                  *              success of the load. If an array is passed instead, two array\r
  31                  *              parameters are passed to the callback; the first contains the\r
  32                  *              URLs that have been properly loaded, and the second the failed\r
  33                  *              ones.\r
  34                  * @param {Object} [scope] The scope ("this" reference) to be used for\r
  35                  *              the callback call. Default to {@link CKEDITOR}.\r
  36                  * @param {Boolean} [noCheck] Indicates that the script must be loaded\r
  37                  *              anyway, not checking if it has already loaded.\r
  38                  * @example\r
  39                  * CKEDITOR.scriptLoader.load( '/myscript.js' );\r
  40                  * @example\r
  41                  * CKEDITOR.scriptLoader.load( '/myscript.js', function( success )\r
  42                  *     {\r
  43                  *         // Alerts "true" if the script has been properly loaded.\r
  44                  *         // HTTP error 404 should return "false".\r
  45                  *         alert( success );\r
  46                  *     });\r
  47                  * @example\r
  48                  * CKEDITOR.scriptLoader.load( [ '/myscript1.js', '/myscript2.js' ], function( completed, failed )\r
  49                  *     {\r
  50                  *         alert( 'Number of scripts loaded: ' + completed.length );\r
  51                  *         alert( 'Number of failures: ' + failed.length );\r
  52                  *     });\r
  53                  */\r
  54                 load : function( scriptUrl, callback, scope, noCheck )\r
  55                 {\r
  56                         var isString = ( typeof scriptUrl == 'string' );\r
  57 \r
  58                         if ( isString )\r
  59                                 scriptUrl = [ scriptUrl ];\r
  60 \r
  61                         if ( !scope )\r
  62                                 scope = CKEDITOR;\r
  63 \r
  64                         var scriptCount = scriptUrl.length,\r
  65                                 completed = [],\r
  66                                 failed = [];\r
  67 \r
  68                         var doCallback = function( success )\r
  69                         {\r
  70                                 if ( callback )\r
  71                                 {\r
  72                                         if ( isString )\r
  73                                                 callback.call( scope, success );\r
  74                                         else\r
  75                                                 callback.call( scope, completed, failed );\r
  76                                 }\r
  77                         };\r
  78 \r
  79                         if ( scriptCount === 0 )\r
  80                         {\r
  81                                 doCallback( true );\r
  82                                 return;\r
  83                         }\r
  84 \r
  85                         var checkLoaded = function( url, success )\r
  86                         {\r
  87                                 ( success ? completed : failed ).push( url );\r
  88 \r
  89                                 if ( --scriptCount <= 0 )\r
  90                                         doCallback( success );\r
  91                         };\r
  92 \r
  93                         var onLoad = function( url, success )\r
  94                         {\r
  95                                 // Mark this script as loaded.\r
  96                                 uniqueScripts[ url ] = 1;\r
  97 \r
  98                                 // Get the list of callback checks waiting for this file.\r
  99                                 var waitingInfo = waitingList[ url ];\r
 100                                 delete waitingList[ url ];\r
 101 \r
 102                                 // Check all callbacks waiting for this file.\r
 103                                 for ( var i = 0 ; i < waitingInfo.length ; i++ )\r
 104                                         waitingInfo[ i ]( url, success );\r
 105                         };\r
 106 \r
 107                         var loadScript = function( url )\r
 108                         {\r
 109                                 if ( noCheck !== true && uniqueScripts[ url ] )\r
 110                                 {\r
 111                                         checkLoaded( url, true );\r
 112                                         return;\r
 113                                 }\r
 114 \r
 115                                 var waitingInfo = waitingList[ url ] || ( waitingList[ url ] = [] );\r
 116                                 waitingInfo.push( checkLoaded );\r
 117 \r
 118                                 // Load it only for the first request.\r
 119                                 if ( waitingInfo.length > 1 )\r
 120                                         return;\r
 121 \r
 122                                 // Create the <script> element.\r
 123                                 var script = new CKEDITOR.dom.element( 'script' );\r
 124                                 script.setAttributes( {\r
 125                                         type : 'text/javascript',\r
 126                                         src : url } );\r
 127 \r
 128                                 if ( callback )\r
 129                                 {\r
 130                                         if ( CKEDITOR.env.ie )\r
 131                                         {\r
 132                                                 // FIXME: For IE, we are not able to return false on error (like 404).\r
 133 \r
 134                                                 /** @ignore */\r
 135                                                 script.$.onreadystatechange = function ()\r
 136                                                 {\r
 137                                                         if ( script.$.readyState == 'loaded' || script.$.readyState == 'complete' )\r
 138                                                         {\r
 139                                                                 script.$.onreadystatechange = null;\r
 140                                                                 onLoad( url, true );\r
 141                                                         }\r
 142                                                 };\r
 143                                         }\r
 144                                         else\r
 145                                         {\r
 146                                                 /** @ignore */\r
 147                                                 script.$.onload = function()\r
 148                                                 {\r
 149                                                         // Some browsers, such as Safari, may call the onLoad function\r
 150                                                         // immediately. Which will break the loading sequence. (#3661)\r
 151                                                         setTimeout( function() { onLoad( url, true ); }, 0 );\r
 152                                                 };\r
 153 \r
 154                                                 // FIXME: Opera and Safari will not fire onerror.\r
 155 \r
 156                                                 /** @ignore */\r
 157                                                 script.$.onerror = function()\r
 158                                                 {\r
 159                                                         onLoad( url, false );\r
 160                                                 };\r
 161                                         }\r
 162                                 }\r
 163 \r
 164                                 // Append it to <head>.\r
 165                                 script.appendTo( CKEDITOR.document.getHead() );\r
 166 \r
 167                                 CKEDITOR.fire( 'download', url );               // @Packager.RemoveLine\r
 168                         };\r
 169 \r
 170                         for ( var i = 0 ; i < scriptCount ; i++ )\r
 171                         {\r
 172                                 loadScript( scriptUrl[ i ] );\r
 173                         }\r
 174                 },\r
 175 \r
 176                 /**\r
 177                  * Executes a JavaScript code into the current document.\r
 178                  * @param {String} code The code to be executed.\r
 179                  * @example\r
 180                  * CKEDITOR.scriptLoader.loadCode( 'var x = 10;' );\r
 181                  * alert( x );  // "10"\r
 182                  */\r
 183                 loadCode : function( code )\r
 184                 {\r
 185                         // Create the <script> element.\r
 186                         var script = new CKEDITOR.dom.element( 'script' );\r
 187                         script.setAttribute( 'type', 'text/javascript' );\r
 188                         script.appendText( code );\r
 189 \r
 190                         // Append it to <head>.\r
 191                         script.appendTo( CKEDITOR.document.getHead() );\r
 192                 }\r
 193         };\r
 194 })();\r