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 ( window.location.protocol !== "file:" ) {
  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
  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                                         // Requested-With header
  96                                         // Not set for crossDomain requests with no content
  97                                         // (see why at http://trac.dojotoolkit.org/ticket/9486)
  98                                         // Won't change header if already provided
  99                                         if ( !( s.crossDomain && !s.hasContent ) && !headers["x-requested-with"] ) {
 100                                                 headers[ "x-requested-with" ] = "XMLHttpRequest";
 101                                         }
 102
 103                                         // Need an extra try/catch for cross domain requests in Firefox 3
 104                                         try {
 105                                                 jQuery.each( headers, function( key, value ) {
 106                                                         xhr.setRequestHeader( key, value );
 107                                                 } );
 108                                         } catch( _ ) {}
 109
 110                                         // Do send the request
 111                                         // This may raise an exception which is actually
 112                                         // handled in jQuery.ajax (so no try/catch here)
 113                                         xhr.send( ( s.hasContent && s.data ) || null );
 114
 115                                         // Listener
 116                                         callback = function( _, isAbort ) {
 117
 118                                                 // Was never called and is aborted or complete
 119                                                 if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
 120
 121                                                         // Only called once
 122                                                         callback = 0;
 123
 124                                                         // Do not keep as active anymore
 125                                                         if ( handle ) {
 126                                                                 xhr.onreadystatechange = jQuery.noop;
 127                                                                 delete xhrs[ handle ];
 128                                                         }
 129
 130                                                         // If it's an abort
 131                                                         if ( isAbort ) {
 132                                                                 // Abort it manually if needed
 133                                                                 if ( xhr.readyState !== 4 ) {
 134                                                                         xhr.abort();
 135                                                                 }
 136                                                         } else {
 137                                                                 // Get info
 138                                                                 var status = xhr.status,
 139                                                                         statusText,
 140                                                                         responseHeaders = xhr.getAllResponseHeaders(),
 141                                                                         responses = {},
 142                                                                         xml = xhr.responseXML;
 143
 144                                                                 // Construct response list
 145                                                                 if ( xml && xml.documentElement /* #4958 */ ) {
 146                                                                         responses.xml = xml;
 147                                                                 }
 148                                                                 responses.text = xhr.responseText;
 149
 150                                                                 // Firefox throws an exception when accessing
 151                                                                 // statusText for faulty cross-domain requests
 152                                                                 try {
 153                                                                         statusText = xhr.statusText;
 154                                                                 } catch( e ) {
 155                                                                         // We normalize with Webkit giving an empty statusText
 156                                                                         statusText = "";
 157                                                                 }
 158
 159                                                                 // Filter status for non standard behaviours
 160                                                                 status =
 161                                                                         // Opera returns 0 when it should be 304
 162                                                                         // Webkit returns 0 for failing cross-domain no matter the real status
 163                                                                         status === 0 ?
 164                                                                                 (
 165                                                                                         // Webkit, Firefox: filter out faulty cross-domain requests
 166                                                                                         !s.crossDomain || statusText ?
 167                                                                                         (
 168                                                                                                 // Opera: filter out real aborts #6060
 169                                                                                                 responseHeaders ?
 170                                                                                                 304 :
 171                                                                                                 0
 172                                                                                         ) :
 173                                                                                         // We assume 302 but could be anything cross-domain related
 174                                                                                         302
 175                                                                                 ) :
 176                                                                                 (
 177                                                                                         // IE sometimes returns 1223 when it should be 204 (see #1450)
 178                                                                                         status == 1223 ?
 179                                                                                                 204 :
 180                                                                                                 status
 181                                                                                 );
 182
 183                                                                 // Call complete
 184                                                                 complete( status, statusText, responses, responseHeaders );
 185                                                         }
 186                                                 }
 187                                         };
 188
 189                                         // if we're in sync mode or it's in cache
 190                                         // and has been retrieved directly (IE6 & IE7)
 191                                         // we need to manually fire the callback
 192                                         if ( !s.async || xhr.readyState === 4 ) {
 193                                                 callback();
 194                                         } else {
 195                                                 // Add to list of active xhrs
 196                                                 handle = xhrId++;
 197                                                 xhrs[ handle ] = xhr;
 198                                                 xhr.onreadystatechange = callback;
 199                                         }
 200                                 },
 201
 202                                 abort: function() {
 203                                         if ( callback ) {
 204                                                 callback(0,1);
 205                                         }
 206                                 }
 207                         };
 208                 }
 209         });
 210 }
 211
 212 })( jQuery );