src/ajax/xhr.js

   1 (function( jQuery ) {
   2
   3 // Functions to create xhrs
   4 function createStandardXHR() {
   5         try {
   6                 return new window.XMLHttpRequest();
   7         } catch( e ) {}
   8 }
   9
  10 function createActiveXHR() {
  11         try {
  12                 return new window.ActiveXObject("Microsoft.XMLHTTP");
  13         } catch( e ) {}
  14 }
  15
  16 var // Next active xhr id
  17         xhrId = jQuery.now(),
  18
  19         // active xhrs
  20         xhrs = {},
  21
  22         // #5280: see below
  23         xhrUnloadAbortInstalled,
  24
  25         // XHR used to determine supports properties
  26         testXHR;
  27
  28 // Create the request object
  29 // (This is still attached to ajaxSettings for backward compatibility)
  30 jQuery.ajaxSettings.xhr = window.ActiveXObject ?
  31         /* Microsoft failed to properly
  32          * implement the XMLHttpRequest in IE7 (can't request local files),
  33          * so we use the ActiveXObject when it is available
  34          * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
  35          * we need a fallback.
  36          */
  37         function() {
  38                 return !this.isLocal && createStandardXHR() || createActiveXHR();
  39         } :
  40         // For all other browsers, use the standard XMLHttpRequest object
  41         createStandardXHR;
  42
  43 // Test if we can create an xhr object
  44 testXHR = jQuery.ajaxSettings.xhr();
  45 jQuery.support.ajax = !!testXHR;
  46
  47 // Does this browser support crossDomain XHR requests
  48 jQuery.support.cors = testXHR && ( "withCredentials" in testXHR );
  49
  50 // No need for the temporary xhr anymore
  51 testXHR = undefined;
  52
  53 // Create transport if the browser can provide an xhr
  54 if ( jQuery.support.ajax ) {
  55
  56         jQuery.ajaxTransport(function( s ) {
  57                 // Cross domain only allowed if supported through XMLHttpRequest
  58                 if ( !s.crossDomain || jQuery.support.cors ) {
  59
  60                         var callback;
  61
  62                         return {
  63                                 send: function( headers, complete ) {
  64
  65                                         // #5280: we need to abort on unload or IE will keep connections alive
  66                                         if ( !xhrUnloadAbortInstalled ) {
  67
  68                                                 xhrUnloadAbortInstalled = 1;
  69
  70                                                 jQuery(window).bind( "unload", function() {
  71
  72                                                         // Abort all pending requests
  73                                                         jQuery.each( xhrs, function( _, xhr ) {
  74                                                                 if ( xhr.onreadystatechange ) {
  75                                                                         xhr.onreadystatechange( 1 );
  76                                                                 }
  77                                                         } );
  78
  79                                                 } );
  80                                         }
  81
  82                                         // Get a new xhr
  83                                         var xhr = s.xhr(),
  84                                                 handle,
  85                                                 i;
  86
  87                                         // Open the socket
  88                                         // Passing null username, generates a login popup on Opera (#2865)
  89                                         if ( s.username ) {
  90                                                 xhr.open( s.type, s.url, s.async, s.username, s.password );
  91                                         } else {
  92                                                 xhr.open( s.type, s.url, s.async );
  93                                         }
  94
  95                                         // Apply custom fields if provided
  96                                         if ( s.xhrFields ) {
  97                                                 for ( i in s.xhrFields ) {
  98                                                         xhr[ i ] = s.xhrFields[ i ];
  99                                                 }
 100                                         }
 101
 102                                         // Requested-With header
 103                                         // Not set for crossDomain requests with no content
 104                                         // (see why at http://trac.dojotoolkit.org/ticket/9486)
 105                                         // Won't change header if already provided
 106                                         if ( !( s.crossDomain && !s.hasContent ) && !headers["x-requested-with"] ) {
 107                                                 headers[ "x-requested-with" ] = "XMLHttpRequest";
 108                                         }
 109
 110                                         // Need an extra try/catch for cross domain requests in Firefox 3
 111                                         try {
 112                                                 jQuery.each( headers, function( key, value ) {
 113                                                         xhr.setRequestHeader( key, value );
 114                                                 } );
 115                                         } catch( _ ) {}
 116
 117                                         // Do send the request
 118                                         // This may raise an exception which is actually
 119                                         // handled in jQuery.ajax (so no try/catch here)
 120                                         xhr.send( ( s.hasContent && s.data ) || null );
 121
 122                                         // Listener
 123                                         callback = function( _, isAbort ) {
 124
 125                                                 var status,
 126                                                         statusText,
 127                                                         responseHeaders,
 128                                                         responses,
 129                                                         xml;
 130
 131                                                 // Firefox throws exceptions when accessing properties
 132                                                 // of an xhr when a network error occured
 133                                                 // http://helpful.knobs-dials.com/index.php/Component_returned_failure_code:_0x80040111_(NS_ERROR_NOT_AVAILABLE)
 134                                                 try {
 135
 136                                                         // Was never called and is aborted or complete
 137                                                         if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
 138
 139                                                                 // Only called once
 140                                                                 callback = undefined;
 141
 142                                                                 // Do not keep as active anymore
 143                                                                 if ( handle ) {
 144                                                                         xhr.onreadystatechange = jQuery.noop;
 145                                                                         delete xhrs[ handle ];
 146                                                                 }
 147
 148                                                                 // If it's an abort
 149                                                                 if ( isAbort ) {
 150                                                                         // Abort it manually if needed
 151                                                                         if ( xhr.readyState !== 4 ) {
 152                                                                                 xhr.abort();
 153                                                                         }
 154                                                                 } else {
 155                                                                         // Get info
 156                                                                         status = xhr.status;
 157                                                                         responseHeaders = xhr.getAllResponseHeaders();
 158                                                                         responses = {};
 159                                                                         xml = xhr.responseXML;
 160
 161                                                                         // Construct response list
 162                                                                         if ( xml && xml.documentElement /* #4958 */ ) {
 163                                                                                 responses.xml = xml;
 164                                                                         }
 165                                                                         responses.text = xhr.responseText;
 166
 167                                                                         // Firefox throws an exception when accessing
 168                                                                         // statusText for faulty cross-domain requests
 169                                                                         try {
 170                                                                                 statusText = xhr.statusText;
 171                                                                         } catch( e ) {
 172                                                                                 // We normalize with Webkit giving an empty statusText
 173                                                                                 statusText = "";
 174                                                                         }
 175
 176                                                                         // Filter status for non standard behaviors
 177
 178                                                                         // IE - #1450: sometimes returns 1223 when it should be 204
 179                                                                         if ( status === 1223 ) {
 180                                                                                 status = 204;
 181                                                                         // Various - #8177: a Not Modified response was received
 182                                                                         // yet no conditional request headers was provided
 183                                                                         } else if ( status === 304 &&
 184                                                                                                 !headers[ "if-modified-since" ] &&
 185                                                                                                 !headers[ "if-none-match" ] ) {
 186                                                                                 status = 200;
 187                                                                         // Status 0 encompasses several cases
 188                                                                         } else if ( !status ) {
 189                                                                                 // Cross-domain
 190                                                                                 if ( s.crossDomain ) {
 191                                                                                         if ( !s.statusText ) {
 192                                                                                                 // FF, Webkit (other?): There is no status text for errors
 193                                                                                                 // 302 is the most generic cross-domain status code
 194                                                                                                 // for errors, could be anything really (even a real 0)
 195                                                                                                 status = 302;
 196                                                                                         }
 197                                                                                 // All same-domain: for local files, 0 is a success
 198                                                                                 } else if( s.isLocal ) {
 199                                                                                         status = 200;
 200                                                                                         // Opera: this notifies success for all requests
 201                                                                                         // (verified in 11.01). Patch welcome.
 202                                                                                 }
 203                                                                                 // Opera - #6060: sets status as 0 for 304
 204                                                                                 // Patch welcome.
 205                                                                         }
 206                                                                 }
 207                                                         }
 208                                                 } catch( firefoxAccessException ) {
 209                                                         if ( !isAbort ) {
 210                                                                 complete( -1, firefoxAccessException );
 211                                                         }
 212                                                 }
 213
 214                                                 // Call complete if needed
 215                                                 if ( responses ) {
 216                                                         complete( status, statusText, responses, responseHeaders );
 217                                                 }
 218                                         };
 219
 220                                         // if we're in sync mode or it's in cache
 221                                         // and has been retrieved directly (IE6 & IE7)
 222                                         // we need to manually fire the callback
 223                                         if ( !s.async || xhr.readyState === 4 ) {
 224                                                 callback();
 225                                         } else {
 226                                                 // Add to list of active xhrs
 227                                                 handle = xhrId++;
 228                                                 xhrs[ handle ] = xhr;
 229                                                 xhr.onreadystatechange = callback;
 230                                         }
 231                                 },
 232
 233                                 abort: function() {
 234                                         if ( callback ) {
 235                                                 callback(0,1);
 236                                         }
 237                                 }
 238                         };
 239                 }
 240         });
 241 }
 242
 243 })( jQuery );