src/ajax/xhr.js

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