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