src/ajax/xhr.js

   1 (function( jQuery ) {
   2
   3 var // Next active xhr id
   4         xhrId = jQuery.now(),
   5
   6         // active xhrs
   7         xhrs = {},
   8
   9         // #5280: see below
  10         xhrUnloadAbortInstalled,
  11
  12         // XHR used to determine supports properties
  13         testXHR;
  14
  15 // Create the request object
  16 // (This is still attached to ajaxSettings for backward compatibility)
  17 jQuery.ajaxSettings.xhr = window.ActiveXObject ?
  18         /* Microsoft failed to properly
  19          * implement the XMLHttpRequest in IE7 (can't request local files),
  20          * so we use the ActiveXObject when it is available
  21          * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
  22          * we need a fallback.
  23          */
  24         function() {
  25                 if ( !jQuery.ajaxSettings.isLocal ) {
  26                         try {
  27                                 return new window.XMLHttpRequest();
  28                         } catch( xhrError ) {}
  29                 }
  30
  31                 try {
  32                         return new window.ActiveXObject("Microsoft.XMLHTTP");
  33                 } catch( activeError ) {}
  34         } :
  35         // For all other browsers, use the standard XMLHttpRequest object
  36         function() {
  37                 return new window.XMLHttpRequest();
  38         };
  39
  40 // Test if we can create an xhr object
  41 try {
  42         testXHR = jQuery.ajaxSettings.xhr();
  43 } catch( xhrCreationException ) {}
  44
  45 //Does this browser support XHR requests?
  46 jQuery.support.ajax = !!testXHR;
  47
  48 // Does this browser support crossDomain XHR requests
  49 jQuery.support.cors = testXHR && ( "withCredentials" in testXHR );
  50
  51 // No need for the temporary xhr anymore
  52 testXHR = undefined;
  53
  54 // Create transport if the browser can provide an xhr
  55 if ( jQuery.support.ajax ) {
  56
  57         jQuery.ajaxTransport(function( s ) {
  58                 // Cross domain only allowed if supported through XMLHttpRequest
  59                 if ( !s.crossDomain || jQuery.support.cors ) {
  60
  61                         var callback;
  62
  63                         return {
  64                                 send: function( headers, complete ) {
  65
  66                                         // #5280: we need to abort on unload or IE will keep connections alive
  67                                         if ( !xhrUnloadAbortInstalled ) {
  68
  69                                                 xhrUnloadAbortInstalled = 1;
  70
  71                                                 jQuery(window).bind( "unload", function() {
  72
  73                                                         // Abort all pending requests
  74                                                         jQuery.each( xhrs, function( _, xhr ) {
  75                                                                 if ( xhr.onreadystatechange ) {
  76                                                                         xhr.onreadystatechange( 1 );
  77                                                                 }
  78                                                         } );
  79
  80                                                 } );
  81                                         }
  82
  83                                         // Get a new xhr
  84                                         var xhr = s.xhr(),
  85                                                 handle,
  86                                                 i;
  87
  88                                         // Apply custom fields if provided
  89                                         if ( s.xhrFields ) {
  90                                                 for ( i in s.xhrFields ) {
  91                                                         xhr[ i ] = s.xhrFields[ i ];
  92                                                 }
  93                                         }
  94
  95                                         // Open the socket
  96                                         // Passing null username, generates a login popup on Opera (#2865)
  97                                         if ( s.username ) {
  98                                                 xhr.open( s.type, s.url, s.async, s.username, s.password );
  99                                         } else {
 100                                                 xhr.open( s.type, s.url, s.async );
 101                                         }
 102
 103                                         // Requested-With header
 104                                         // Not set for crossDomain requests with no content
 105                                         // (see why at http://trac.dojotoolkit.org/ticket/9486)
 106                                         // Won't change header if already provided
 107                                         if ( !( s.crossDomain && !s.hasContent ) && !headers["x-requested-with"] ) {
 108                                                 headers[ "x-requested-with" ] = "XMLHttpRequest";
 109                                         }
 110
 111                                         // Need an extra try/catch for cross domain requests in Firefox 3
 112                                         try {
 113                                                 jQuery.each( headers, function( key, value ) {
 114                                                         xhr.setRequestHeader( key, value );
 115                                                 } );
 116                                         } catch( _ ) {}
 117
 118                                         // Do send the request
 119                                         // This may raise an exception which is actually
 120                                         // handled in jQuery.ajax (so no try/catch here)
 121                                         xhr.send( ( s.hasContent && s.data ) || null );
 122
 123                                         // Listener
 124                                         callback = function( _, isAbort ) {
 125
 126                                                 var status,
 127                                                         statusText,
 128                                                         responseHeaders,
 129                                                         responses,
 130                                                         xml;
 131
 132                                                 // Firefox throws exceptions when accessing properties
 133                                                 // of an xhr when a network error occured
 134                                                 // http://helpful.knobs-dials.com/index.php/Component_returned_failure_code:_0x80040111_(NS_ERROR_NOT_AVAILABLE)
 135                                                 try {
 136
 137                                                         // Was never called and is aborted or complete
 138                                                         if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
 139
 140                                                                 // Only called once
 141                                                                 callback = undefined;
 142
 143                                                                 // Do not keep as active anymore
 144                                                                 if ( handle ) {
 145                                                                         xhr.onreadystatechange = jQuery.noop;
 146                                                                         delete xhrs[ handle ];
 147                                                                 }
 148
 149                                                                 // If it's an abort
 150                                                                 if ( isAbort ) {
 151                                                                         // Abort it manually if needed
 152                                                                         if ( xhr.readyState !== 4 ) {
 153                                                                                 xhr.abort();
 154                                                                         }
 155                                                                 } else {
 156                                                                         // Get info
 157                                                                         status = xhr.status;
 158                                                                         responseHeaders = xhr.getAllResponseHeaders();
 159                                                                         responses = {};
 160                                                                         xml = xhr.responseXML;
 161
 162                                                                         // Construct response list
 163                                                                         if ( xml && xml.documentElement /* #4958 */ ) {
 164                                                                                 responses.xml = xml;
 165                                                                         }
 166                                                                         responses.text = xhr.responseText;
 167
 168                                                                         // Firefox throws an exception when accessing
 169                                                                         // statusText for faulty cross-domain requests
 170                                                                         try {
 171                                                                                 statusText = xhr.statusText;
 172                                                                         } catch( e ) {
 173                                                                                 // We normalize with Webkit giving an empty statusText
 174                                                                                 statusText = "";
 175                                                                         }
 176
 177                                                                         // Filter status for non standard behaviors
 178
 179                                                                         // IE - #1450: sometimes returns 1223 when it should be 204
 180                                                                         if ( status === 1223 ) {
 181                                                                                 status = 204;
 182                                                                         // Status 0 encompasses several cases
 183                                                                         } else if ( !status ) {
 184                                                                                 // Cross-domain
 185                                                                                 if ( s.crossDomain ) {
 186                                                                                         if ( !s.statusText ) {
 187                                                                                                 // FF, Webkit (other?): There is no status text for errors
 188                                                                                                 // 302 is the most generic cross-domain status code
 189                                                                                                 // for errors, could be anything really (even a real 0)
 190                                                                                                 status = 302;
 191                                                                                         }
 192                                                                                 // All same-domain - #8125, #8152: for local files, 0 is a success
 193                                                                                 } else if( s.isLocal ) {
 194                                                                                         status = 200;
 195                                                                                 }
 196                                                                                 // Opera - #6060: sets status as 0 for 304
 197                                                                                 // and there doesn't seem to be any way to
 198                                                                                 // detect this case. Patch VERY welcome.
 199                                                                         }
 200                                                                 }
 201                                                         }
 202                                                 } catch( firefoxAccessException ) {
 203                                                         if ( !isAbort ) {
 204                                                                 complete( -1, firefoxAccessException );
 205                                                         }
 206                                                 }
 207
 208                                                 // Call complete if needed
 209                                                 if ( responses ) {
 210                                                         complete( status, statusText, responses, responseHeaders );
 211                                                 }
 212                                         };
 213
 214                                         // if we're in sync mode or it's in cache
 215                                         // and has been retrieved directly (IE6 & IE7)
 216                                         // we need to manually fire the callback
 217                                         if ( !s.async || xhr.readyState === 4 ) {
 218                                                 callback();
 219                                         } else {
 220                                                 // Add to list of active xhrs
 221                                                 handle = xhrId++;
 222                                                 xhrs[ handle ] = xhr;
 223                                                 xhr.onreadystatechange = callback;
 224                                         }
 225                                 },
 226
 227                                 abort: function() {
 228                                         if ( callback ) {
 229                                                 callback(0,1);
 230                                         }
 231                                 }
 232                         };
 233                 }
 234         });
 235 }
 236
 237 })( jQuery );