_source/core/ajax.js

   1 /*\r
   2 Copyright (c) 2003-2010, 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.ajax} object, which holds ajax methods for\r
   8  *              data loading.\r
   9  */\r
  10 \r
  11 /**\r
  12  * Ajax methods for data loading.\r
  13  * @namespace\r
  14  * @example\r
  15  */\r
  16 CKEDITOR.ajax = (function()\r
  17 {\r
  18         var createXMLHttpRequest = function()\r
  19         {\r
  20                 // In IE, using the native XMLHttpRequest for local files may throw\r
  21                 // "Access is Denied" errors.\r
  22                 if ( !CKEDITOR.env.ie || location.protocol != 'file:' )\r
  23                         try { return new XMLHttpRequest(); } catch(e) {}\r
  24 \r
  25                 try { return new ActiveXObject( 'Msxml2.XMLHTTP' ); } catch (e) {}\r
  26                 try { return new ActiveXObject( 'Microsoft.XMLHTTP' ); } catch (e) {}\r
  27 \r
  28                 return null;\r
  29         };\r
  30 \r
  31         var checkStatus = function( xhr )\r
  32         {\r
  33                 // HTTP Status Codes:\r
  34                 //       2xx : Success\r
  35                 //       304 : Not Modified\r
  36                 //         0 : Returned when running locally (file://)\r
  37                 //      1223 : IE may change 204 to 1223 (see http://dev.jquery.com/ticket/1450)\r
  38 \r
  39                 return ( xhr.readyState == 4 &&\r
  40                                 (       ( xhr.status >= 200 && xhr.status < 300 ) ||\r
  41                                         xhr.status == 304 ||\r
  42                                         xhr.status === 0 ||\r
  43                                         xhr.status == 1223 ) );\r
  44         };\r
  45 \r
  46         var getResponseText = function( xhr )\r
  47         {\r
  48                 if ( checkStatus( xhr ) )\r
  49                         return xhr.responseText;\r
  50                 return null;\r
  51         };\r
  52 \r
  53         var getResponseXml = function( xhr )\r
  54         {\r
  55                 if ( checkStatus( xhr ) )\r
  56                 {\r
  57                         var xml = xhr.responseXML;\r
  58                         return new CKEDITOR.xml( xml && xml.firstChild ? xml : xhr.responseText );\r
  59                 }\r
  60                 return null;\r
  61         };\r
  62 \r
  63         var load = function( url, callback, getResponseFn )\r
  64         {\r
  65                 var async = !!callback;\r
  66 \r
  67                 var xhr = createXMLHttpRequest();\r
  68 \r
  69                 if ( !xhr )\r
  70                         return null;\r
  71 \r
  72                 xhr.open( 'GET', url, async );\r
  73 \r
  74                 if ( async )\r
  75                 {\r
  76                         // TODO: perform leak checks on this closure.\r
  77                         /** @ignore */\r
  78                         xhr.onreadystatechange = function()\r
  79                         {\r
  80                                 if ( xhr.readyState == 4 )\r
  81                                 {\r
  82                                         callback( getResponseFn( xhr ) );\r
  83                                         xhr = null;\r
  84                                 }\r
  85                         };\r
  86                 }\r
  87 \r
  88                 xhr.send(null);\r
  89 \r
  90                 return async ? '' : getResponseFn( xhr );\r
  91         };\r
  92 \r
  93         return  /** @lends CKEDITOR.ajax */ {\r
  94 \r
  95                 /**\r
  96                  * Loads data from an URL as plain text.\r
  97                  * @param {String} url The URL from which load data.\r
  98                  * @param {Function} [callback] A callback function to be called on\r
  99                  *              data load. If not provided, the data will be loaded\r
 100                  *              asynchronously, passing the data value the function on load.\r
 101                  * @returns {String} The loaded data. For asynchronous requests, an\r
 102                  *              empty string. For invalid requests, null.\r
 103                  * @example\r
 104                  * // Load data synchronously.\r
 105                  * var data = CKEDITOR.ajax.load( 'somedata.txt' );\r
 106                  * alert( data );\r
 107                  * @example\r
 108                  * // Load data asynchronously.\r
 109                  * var data = CKEDITOR.ajax.load( 'somedata.txt', function( data )\r
 110                  *     {\r
 111                  *         alert( data );\r
 112                  *     } );\r
 113                  */\r
 114                 load : function( url, callback )\r
 115                 {\r
 116                         return load( url, callback, getResponseText );\r
 117                 },\r
 118 \r
 119                 /**\r
 120                  * Loads data from an URL as XML.\r
 121                  * @param {String} url The URL from which load data.\r
 122                  * @param {Function} [callback] A callback function to be called on\r
 123                  *              data load. If not provided, the data will be loaded\r
 124                  *              asynchronously, passing the data value the function on load.\r
 125                  * @returns {CKEDITOR.xml} An XML object holding the loaded data. For asynchronous requests, an\r
 126                  *              empty string. For invalid requests, null.\r
 127                  * @example\r
 128                  * // Load XML synchronously.\r
 129                  * var xml = CKEDITOR.ajax.loadXml( 'somedata.xml' );\r
 130                  * alert( xml.getInnerXml( '//' ) );\r
 131                  * @example\r
 132                  * // Load XML asynchronously.\r
 133                  * var data = CKEDITOR.ajax.loadXml( 'somedata.xml', function( xml )\r
 134                  *     {\r
 135                  *         alert( xml.getInnerXml( '//' ) );\r
 136                  *     } );\r
 137                  */\r
 138                 loadXml : function( url, callback )\r
 139                 {\r
 140                         return load( url, callback, getResponseXml );\r
 141                 }\r
 142         };\r
 143 })();\r