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
  13 jQuery.ajaxTransport( function( s , determineDataType ) {
  14
  15         // Cross domain only allowed if supported through XMLHttpRequest
  16         if ( ! s.crossDomain || jQuery.support.cors ) {
  17
  18                 var callback;
  19
  20                 return {
  21
  22                         send: function(headers, complete) {
  23
  24                                 // #5280: we need to abort on unload or IE will keep connections alive
  25                                 if ( ! xhrUnloadAbortInstalled ) {
  26
  27                                         xhrUnloadAbortInstalled = 1;
  28
  29                                         jQuery(window).bind( "unload" , function() {
  30
  31                                                 // Abort all pending requests
  32                                                 jQuery.each(xhrs, function(_, xhr) {
  33                                                         if ( xhr.onreadystatechange ) {
  34                                                                 xhr.onreadystatechange( 1 );
  35                                                         }
  36                                                 });
  37
  38                                         });
  39                                 }
  40
  41                                 // Get a new xhr
  42                                 var xhr = s.xhr(),
  43                                         handle;
  44
  45                                 // Open the socket
  46                                 // Passing null username, generates a login popup on Opera (#2865)
  47                                 if ( s.username ) {
  48                                         xhr.open(s.type, s.url, s.async, s.username, s.password);
  49                                 } else {
  50                                         xhr.open(s.type, s.url, s.async);
  51                                 }
  52
  53                                 // Requested-With header
  54                                 // Not set for crossDomain requests with no content
  55                                 // (see why at http://trac.dojotoolkit.org/ticket/9486)
  56                                 // Won't change header if already provided
  57                                 if ( ! ( s.crossDomain && ! s.hasContent ) && ! headers["x-requested-with"] ) {
  58                                         headers["x-requested-with"] = "XMLHttpRequest";
  59                                 }
  60
  61                                 // Need an extra try/catch for cross domain requests in Firefox 3
  62                                 try {
  63
  64                                         jQuery.each(headers, function(key,value) {
  65                                                 xhr.setRequestHeader(key,value);
  66                                         });
  67
  68                                 } catch(_) {}
  69
  70                                 // Do send the request
  71                                 try {
  72                                         xhr.send( ( s.hasContent && s.data ) || null );
  73                                 } catch(e) {
  74                                         complete(0, "error", "" + e);
  75                                         return;
  76                                 }
  77
  78                                 // Listener
  79                                 callback = function( _ , isAbort ) {
  80
  81                                         // Was never called and is aborted or complete
  82                                         if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
  83
  84                                                 // Only called once
  85                                                 callback = 0;
  86
  87                                                 // Do not keep as active anymore
  88                                                 // and store back into pool
  89                                                 if (handle) {
  90                                                         xhr.onreadystatechange = jQuery.noop;
  91                                                         delete xhrs[ handle ];
  92                                                 }
  93
  94                                                 // If it's an abort
  95                                                 if ( isAbort ) {
  96
  97                                                         // Abort it manually if needed
  98                                                         if ( xhr.readyState !== 4 ) {
  99                                                                 xhr.abort();
 100                                                         }
 101                                                 } else {
 102
 103                                                         // Get info
 104                                                         var status = xhr.status,
 105                                                                 statusText,
 106                                                                 response,
 107                                                                 responseHeaders = xhr.getAllResponseHeaders();
 108
 109                                                         try { // Firefox throws an exception when accessing statusText for faulty cross-domain requests
 110
 111                                                                 statusText = xhr.statusText;
 112
 113                                                         } catch( e ) {
 114
 115                                                                 statusText = ""; // We normalize with Webkit giving an empty statusText
 116
 117                                                         }
 118
 119                                                         // Filter status for non standard behaviours
 120                                                         // (so many they seem to be the actual "standard")
 121                                                         status =
 122                                                                 // Opera returns 0 when it should be 304
 123                                                                 // Webkit returns 0 for failing cross-domain no matter the real status
 124                                                                 status === 0 ?
 125                                                                         (
 126                                                                                 ! s.crossDomain || statusText ? // Webkit, Firefox: filter out faulty cross-domain requests
 127                                                                                 (
 128                                                                                         responseHeaders ? // Opera: filter out real aborts #6060
 129                                                                                         304
 130                                                                                         :
 131                                                                                         0
 132                                                                                 )
 133                                                                                 :
 134                                                                                 302 // We assume 302 but could be anything cross-domain related
 135                                                                         )
 136                                                                         :
 137                                                                         (
 138                                                                                 status == 1223 ?        // IE sometimes returns 1223 when it should be 204 (see #1450)
 139                                                                                         204
 140                                                                                         :
 141                                                                                         status
 142                                                                         );
 143
 144                                                         // Guess response & update dataType accordingly
 145                                                         response =
 146                                                                 determineDataType(
 147                                                                         s,
 148                                                                         xhr.getResponseHeader("content-type"),
 149                                                                         xhr.responseText,
 150                                                                         xhr.responseXML );
 151
 152                                                         // Call complete
 153                                                         complete(status,statusText,response,responseHeaders);
 154                                                 }
 155                                         }
 156                                 };
 157
 158                                 // if we're in sync mode
 159                                 // or it's in cache and has been retrieved directly (IE6 & IE7)
 160                                 // we need to manually fire the callback
 161                                 if ( ! s.async || xhr.readyState === 4 ) {
 162
 163                                         callback();
 164
 165                                 } else {
 166
 167                                         // Add to list of active xhrs
 168                                         handle = xhrId++;
 169                                         xhrs[ handle ] = xhr;
 170                                         xhr.onreadystatechange = callback;
 171                                 }
 172                         },
 173
 174                         abort: function() {
 175                                 if ( callback ) {
 176                                         callback(0,1);
 177                                 }
 178                         }
 179                 };
 180         }
 181 });
 182
 183 })( jQuery );