Fixes #8177. XHR transport now considers 304 Not Modified responses as 200 OK if...
[jquery.git] / src / ajax / xhr.js
index 7d71402..b18274c 100644 (file)
 (function( jQuery ) {
 
-var // Next fake timer id
-       xhrPollingId = jQuery.now(),
-
-       // Callbacks hashtable
+// Functions to create xhrs
+function createStandardXHR() {
+       try {
+               return new window.XMLHttpRequest();
+       } catch( e ) {}
+}
+
+function createActiveXHR() {
+       try {
+               return new window.ActiveXObject("Microsoft.XMLHTTP");
+       } catch( e ) {}
+}
+
+var // Next active xhr id
+       xhrId = jQuery.now(),
+
+       // active xhrs
        xhrs = {},
 
-       // #5280: see end of file
-       xhrUnloadAbortMarker = [];
+       // #5280: see below
+       xhrUnloadAbortInstalled,
 
+       // XHR used to determine supports properties
+       testXHR;
 
-jQuery.ajax.transport( function( s , determineDataType ) {
+// Create the request object
+// (This is still attached to ajaxSettings for backward compatibility)
+jQuery.ajaxSettings.xhr = window.ActiveXObject ?
+       /* Microsoft failed to properly
+        * implement the XMLHttpRequest in IE7 (can't request local files),
+        * so we use the ActiveXObject when it is available
+        * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
+        * we need a fallback.
+        */
+       function() {
+               return !this.isLocal && createStandardXHR() || createActiveXHR();
+       } :
+       // For all other browsers, use the standard XMLHttpRequest object
+       createStandardXHR;
 
-       // Cross domain only allowed if supported through XMLHttpRequest
-       if ( ! s.crossDomain || jQuery.support.cors ) {
+// Test if we can create an xhr object
+testXHR = jQuery.ajaxSettings.xhr();
+jQuery.support.ajax = !!testXHR;
 
-               var callback;
+// Does this browser support crossDomain XHR requests
+jQuery.support.cors = testXHR && ( "withCredentials" in testXHR );
 
-               return {
+// No need for the temporary xhr anymore
+testXHR = undefined;
 
-                       send: function(headers, complete) {
+// Create transport if the browser can provide an xhr
+if ( jQuery.support.ajax ) {
 
-                               var xhr = s.xhr(),
-                                       handle;
+       jQuery.ajaxTransport(function( s ) {
+               // Cross domain only allowed if supported through XMLHttpRequest
+               if ( !s.crossDomain || jQuery.support.cors ) {
 
-                               // Open the socket
-                               // Passing null username, generates a login popup on Opera (#2865)
-                               if ( s.username ) {
-                                       xhr.open(s.type, s.url, s.async, s.username, s.password);
-                               } else {
-                                       xhr.open(s.type, s.url, s.async);
-                               }
+                       var callback;
 
-                               // Requested-With header
-                               // Not set for crossDomain requests with no content
-                               // (see why at http://trac.dojotoolkit.org/ticket/9486)
-                               // Won't change header if already provided in beforeSend
-                               if ( ! ( s.crossDomain && ! s.hasContent ) && ! headers["x-requested-with"] ) {
-                                       headers["x-requested-with"] = "XMLHttpRequest";
-                               }
+                       return {
+                               send: function( headers, complete ) {
 
-                               // Need an extra try/catch for cross domain requests in Firefox 3
-                               try {
+                                       // #5280: we need to abort on unload or IE will keep connections alive
+                                       if ( !xhrUnloadAbortInstalled ) {
 
-                                       jQuery.each(headers, function(key,value) {
-                                               xhr.setRequestHeader(key,value);
-                                       });
+                                               xhrUnloadAbortInstalled = 1;
 
-                               } catch(_) {}
+                                               jQuery(window).bind( "unload", function() {
 
-                               // Do send the request
-                               try {
-                                       xhr.send( ( s.hasContent && s.data ) || null );
-                               } catch(e) {
-                                       complete(0, "error", "" + e);
-                                       return;
-                               }
+                                                       // Abort all pending requests
+                                                       jQuery.each( xhrs, function( _, xhr ) {
+                                                               if ( xhr.onreadystatechange ) {
+                                                                       xhr.onreadystatechange( 1 );
+                                                               }
+                                                       } );
 
-                               // Listener
-                               callback = function ( abortStatusText ) {
+                                               } );
+                                       }
 
-                                       // Was never called and is aborted or complete
-                                       if ( callback && ( abortStatusText || xhr.readyState === 4 ) ) {
+                                       // Get a new xhr
+                                       var xhr = s.xhr(),
+                                               handle,
+                                               i;
+
+                                       // Open the socket
+                                       // Passing null username, generates a login popup on Opera (#2865)
+                                       if ( s.username ) {
+                                               xhr.open( s.type, s.url, s.async, s.username, s.password );
+                                       } else {
+                                               xhr.open( s.type, s.url, s.async );
+                                       }
 
-                                               // Do not listen anymore
-                                               if (handle) {
-                                                       xhr.onreadystatechange = jQuery.noop;
-                                                       delete xhrs[ handle ];
-                                                       handle = undefined;
+                                       // Apply custom fields if provided
+                                       if ( s.xhrFields ) {
+                                               for ( i in s.xhrFields ) {
+                                                       xhr[ i ] = s.xhrFields[ i ];
                                                }
+                                       }
 
-                                               callback = 0;
-
-                                               // Get info
-                                               var status, statusText, response, responseHeaders;
-
-                                               if ( abortStatusText ) {
-
-                                                       if ( xhr.readyState !== 4 ) {
-                                                               xhr.abort();
-                                                       }
-
-                                                       // Stop here if unloadAbort
-                                                       if ( abortStatusText === xhrUnloadAbortMarker ) {
-                                                               return;
-                                                       }
-
-                                                       status = 0;
-                                                       statusText = abortStatusText;
-
-                                               } else {
-
-                                                       status = xhr.status;
-
-                                                       try { // Firefox throws an exception when accessing statusText for faulty cross-domain requests
-
-                                                               statusText = xhr.statusText;
+                                       // Requested-With header
+                                       // Not set for crossDomain requests with no content
+                                       // (see why at http://trac.dojotoolkit.org/ticket/9486)
+                                       // Won't change header if already provided
+                                       if ( !( s.crossDomain && !s.hasContent ) && !headers["x-requested-with"] ) {
+                                               headers[ "x-requested-with" ] = "XMLHttpRequest";
+                                       }
 
-                                                       } catch( e ) {
+                                       // Need an extra try/catch for cross domain requests in Firefox 3
+                                       try {
+                                               jQuery.each( headers, function( key, value ) {
+                                                       xhr.setRequestHeader( key, value );
+                                               } );
+                                       } catch( _ ) {}
 
-                                                               statusText = ""; // We normalize with Webkit giving an empty statusText
+                                       // Do send the request
+                                       // This may raise an exception which is actually
+                                       // handled in jQuery.ajax (so no try/catch here)
+                                       xhr.send( ( s.hasContent && s.data ) || null );
 
+                                       // Listener
+                                       callback = function( _, isAbort ) {
+
+                                               var status,
+                                                       statusText,
+                                                       responseHeaders,
+                                                       responses,
+                                                       xml;
+
+                                               // Firefox throws exceptions when accessing properties
+                                               // of an xhr when a network error occured
+                                               // http://helpful.knobs-dials.com/index.php/Component_returned_failure_code:_0x80040111_(NS_ERROR_NOT_AVAILABLE)
+                                               try {
+
+                                                       // Was never called and is aborted or complete
+                                                       if ( callback && ( isAbort || xhr.readyState === 4 ) ) {
+
+                                                               // Only called once
+                                                               callback = undefined;
+
+                                                               // Do not keep as active anymore
+                                                               if ( handle ) {
+                                                                       xhr.onreadystatechange = jQuery.noop;
+                                                                       delete xhrs[ handle ];
+                                                               }
+
+                                                               // If it's an abort
+                                                               if ( isAbort ) {
+                                                                       // Abort it manually if needed
+                                                                       if ( xhr.readyState !== 4 ) {
+                                                                               xhr.abort();
+                                                                       }
+                                                               } else {
+                                                                       // Get info
+                                                                       status = xhr.status;
+                                                                       responseHeaders = xhr.getAllResponseHeaders();
+                                                                       responses = {};
+                                                                       xml = xhr.responseXML;
+
+                                                                       // Construct response list
+                                                                       if ( xml && xml.documentElement /* #4958 */ ) {
+                                                                               responses.xml = xml;
+                                                                       }
+                                                                       responses.text = xhr.responseText;
+
+                                                                       // Firefox throws an exception when accessing
+                                                                       // statusText for faulty cross-domain requests
+                                                                       try {
+                                                                               statusText = xhr.statusText;
+                                                                       } catch( e ) {
+                                                                               // We normalize with Webkit giving an empty statusText
+                                                                               statusText = "";
+                                                                       }
+
+                                                                       // Filter status for non standard behaviors
+
+                                                                       // IE - #1450: sometimes returns 1223 when it should be 204
+                                                                       if ( status === 1223 ) {
+                                                                               status = 204;
+                                                                       // Various - #8177: a Not Modified response was received
+                                                                       // yet no conditional request headers was provided
+                                                                       } else if ( status === 304 &&
+                                                                                               !headers[ "if-modified-since" ] &&
+                                                                                               !headers[ "if-none-match" ] ) {
+                                                                               status = 200;
+                                                                       // Status 0 encompasses several cases
+                                                                       } else if ( !status ) {
+                                                                               // Cross-domain
+                                                                               if ( s.crossDomain ) {
+                                                                                       if ( !s.statusText ) {
+                                                                                               // FF, Webkit (other?): There is no status text for errors
+                                                                                               // 302 is the most generic cross-domain status code
+                                                                                               // for errors, could be anything really (even a real 0)
+                                                                                               status = 302;
+                                                                                       }
+                                                                               // All same-domain: for local files, 0 is a success
+                                                                               } else if( s.isLocal ) {
+                                                                                       status = 200;
+                                                                                       // Opera: this notifies success for all requests
+                                                                                       // (verified in 11.01). Patch welcome.
+                                                                               }
+                                                                               // Opera - #6060: sets status as 0 for 304
+                                                                               // Patch welcome.
+                                                                       }
+                                                               }
                                                        }
-
-                                                       responseHeaders = xhr.getAllResponseHeaders();
-
-                                                       // Filter status for non standard behaviours
-                                                       // (so many they seem to be the actual "standard")
-                                                       status =
-                                                               // Opera returns 0 when it should be 304
-                                                               // Webkit returns 0 for failing cross-domain no matter the real status
-                                                               status === 0 ?
-                                                                       (
-                                                                               ! s.crossDomain || statusText ? // Webkit, Firefox: filter out faulty cross-domain requests
-                                                                               (
-                                                                                       responseHeaders ? // Opera: filter out real aborts #6060
-                                                                                       304
-                                                                                       :
-                                                                                       0
-                                                                               )
-                                                                               :
-                                                                               302 // We assume 302 but could be anything cross-domain related
-                                                                       )
-                                                                       :
-                                                                       (
-                                                                               status == 1223 ?        // IE sometimes returns 1223 when it should be 204 (see #1450)
-                                                                                       204
-                                                                                       :
-                                                                                       status
-                                                                       );
-
-                                                       // Guess response if needed & update datatype accordingly
-                                                       if ( status >= 200 && status < 300 ) {
-                                                               response =
-                                                                       determineDataType(
-                                                                               s,
-                                                                               xhr.getResponseHeader("content-type"),
-                                                                               xhr.responseText,
-                                                                               xhr.responseXML );
+                                               } catch( firefoxAccessException ) {
+                                                       if ( !isAbort ) {
+                                                               complete( -1, firefoxAccessException );
                                                        }
                                                }
 
-                                               // Call complete
-                                               complete(status,statusText,response,responseHeaders);
-                                       }
-                               };
-
-                               // if we're in sync mode
-                               // or it's in cache and has been retrieved directly (IE6 & IE7)
-                               // we need to manually fire the callback
-                               if ( ! s.async || xhr.readyState === 4 ) {
-
-                                       callback();
-
-                               } else {
+                                               // Call complete if needed
+                                               if ( responses ) {
+                                                       complete( status, statusText, responses, responseHeaders );
+                                               }
+                                       };
 
-                                       // Listener is externalized to handle abort on unload
-                                       handle = xhrPollingId++;
-                                       xhrs[ handle ] = xhr;
-                                       xhr.onreadystatechange = function() {
+                                       // if we're in sync mode or it's in cache
+                                       // and has been retrieved directly (IE6 & IE7)
+                                       // we need to manually fire the callback
+                                       if ( !s.async || xhr.readyState === 4 ) {
                                                callback();
-                                       };
-                               }
-                       },
+                                       } else {
+                                               // Add to list of active xhrs
+                                               handle = xhrId++;
+                                               xhrs[ handle ] = xhr;
+                                               xhr.onreadystatechange = callback;
+                                       }
+                               },
 
-                       abort: function(statusText) {
-                               if ( callback ) {
-                                       callback(statusText);
+                               abort: function() {
+                                       if ( callback ) {
+                                               callback(0,1);
+                                       }
                                }
-                       }
-               };
-       }
-});
-
-// #5280: we need to abort on unload or IE will keep connections alive
-jQuery(window).bind( "unload" , function() {
-
-       // Abort all pending requests
-       jQuery.each(xhrs, function(_, xhr) {
-               if ( xhr.onreadystatechange ) {
-                       xhr.onreadystatechange( xhrUnloadAbortMarker );
+                       };
                }
        });
-
-       // Resest polling structure to be safe
-       xhrs = {};
-
-});
+}
 
 })( jQuery );