2.0: reduced xhr transport

1 files changed, 84 insertions, 210 deletions

diff --git a/src/ajax/xhr.js b/src/ajax/xhr.js
index 3c1fde374..9569c7064 100644
--- a/src/ajax/xhr.js
+++ b/src/ajax/xhr.js
@@ -1,218 +1,92 @@
-var xhrCallbacks, xhrSupported,
-	xhrId = 0,
-	// #5280: Internet Explorer will keep connections alive if we don't abort on unload
-	xhrOnUnloadAbort = window.ActiveXObject && function() {
-		// Abort all pending requests
-		var key;
-		for ( key in xhrCallbacks ) {
-			xhrCallbacks[ key ]( undefined, true );
-		}
-	};
-
-// Functions to create xhrs
-function createStandardXHR() {
+jQuery.ajaxSettings.xhr = function() {
 	try {
-		return new window.XMLHttpRequest();
+		return new XMLHttpRequest();
 	} catch( e ) {}
-}
-
-function createActiveXHR() {
-	try {
-		return new window.ActiveXObject("Microsoft.XMLHTTP");
-	} catch( e ) {}
-}
-
-// 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;
-
-// Determine support properties
-xhrSupported = jQuery.ajaxSettings.xhr();
+};
+
+var xhrSupported = jQuery.ajaxSettings.xhr(),
+	xhrSuccessStatus = {
+		// file protocol always yields status code 0, assume 200
+		0: 200,
+		// IE - #1450: sometimes returns 1223 when it should be 204
+		1223: 204
+	};
+	
 jQuery.support.cors = !!xhrSupported && ( "withCredentials" in xhrSupported );
-xhrSupported = jQuery.support.ajax = !!xhrSupported;
-
-// Create transport if the browser can provide an xhr
-if ( xhrSupported ) {
-
-	jQuery.ajaxTransport(function( s ) {
-		// Cross domain only allowed if supported through XMLHttpRequest
-		if ( !s.crossDomain || jQuery.support.cors ) {
-
-			var callback;
-
-			return {
-				send: function( headers, complete ) {
-
-					// Get a new xhr
-					var handle, i,
-						xhr = s.xhr();
-
-					// 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 );
-					}
-
-					// Apply custom fields if provided
-					if ( s.xhrFields ) {
-						for ( i in s.xhrFields ) {
-							xhr[ i ] = s.xhrFields[ i ];
-						}
-					}
-
-					// Override mime type if needed
-					if ( s.mimeType && xhr.overrideMimeType ) {
-						xhr.overrideMimeType( s.mimeType );
+jQuery.support.ajax = xhrSupported = !!xhrSupported;
+
+jQuery.ajaxTransport(function( options ) {
+	var callback;
+	// Cross domain only allowed if supported through XMLHttpRequest
+	if ( jQuery.support.cors || xhrSupported && !options.crossDomain ) {
+		return {
+			send: function( headers, complete ) {
+				var i,
+					xhr = options.xhr();
+				// Open the socket
+				xhr.open( options.type, options.url, options.async, options.username, options.password );
+				// Apply custom fields if provided
+				if ( options.xhrFields ) {
+					for ( i in options.xhrFields ) {
+						xhr[ i ] = options.xhrFields[ i ];
 					}
-
-					// X-Requested-With header
-					// For cross-domain requests, seeing as conditions for a preflight are
-					// akin to a jigsaw puzzle, we simply never set it to be sure.
-					// (it can always be set on a per-request basis or even using ajaxSetup)
-					// For same-domain requests, won't change header if already provided.
-					if ( !s.crossDomain && !headers["X-Requested-With"] ) {
-						headers["X-Requested-With"] = "XMLHttpRequest";
-					}
-
-					// Need an extra try/catch for cross domain requests in Firefox 3
-					try {
-						for ( i in headers ) {
-							xhr.setRequestHeader( i, headers[ i ] );
-						}
-					} catch( err ) {}
-
-					// 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 occurred
-						// 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;
-									if ( xhrOnUnloadAbort ) {
-										delete xhrCallbacks[ handle ];
-									}
-								}
-
-								// If it's an abort
-								if ( isAbort ) {
-									// Abort it manually if needed
-									if ( xhr.readyState !== 4 ) {
-										xhr.abort();
-									}
-								} else {
-									responses = {};
-									status = xhr.status;
-									xml = xhr.responseXML;
-									responseHeaders = xhr.getAllResponseHeaders();
-
-									// Construct response list
-									if ( xml && xml.documentElement /* #4958 */ ) {
-										responses.xml = xml;
-									}
-
-									// When requesting binary data, IE6-9 will throw an exception
-									// on any attempt to access responseText (#11426)
-									if ( typeof xhr.responseText === "string" ) {
-										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
-
-									// If the request is local and we have data: assume a success
-									// (success with no data won't get notified, that's the best we
-									// can do given current implementations)
-									if ( !status && s.isLocal && !s.crossDomain ) {
-										status = responses.text ? 200 : 404;
-									// IE - #1450: sometimes returns 1223 when it should be 204
-									} else if ( status === 1223 ) {
-										status = 204;
-									}
-								}
-							}
-						} catch( firefoxAccessException ) {
-							if ( !isAbort ) {
-								complete( -1, firefoxAccessException );
+				}
+				// Override mime type if needed
+				if ( options.mimeType && xhr.overrideMimeType ) {
+					xhr.overrideMimeType( options.mimeType );
+				}
+				// X-Requested-With header
+				// For cross-domain requests, seeing as conditions for a preflight are
+				// akin to a jigsaw puzzle, we simply never set it to be sure.
+				// (it can always be set on a per-request basis or even using ajaxSetup)
+				// For same-domain requests, won't change header if already provided.
+				if ( !options.crossDomain && !headers["X-Requested-With"] ) {
+					headers["X-Requested-With"] = "XMLHttpRequest";
+				}
+				// Set headers
+				for ( i in headers ) {
+					xhr.setRequestHeader( i, headers[ i ] );
+				}
+				// Callback
+				callback = function( type ) {
+					return function() {
+						if ( callback ) {
+							callback = xhr.onload = xhr.onerror = null;
+							if ( type === "abort" ) {
+								xhr.abort();
+							} else if ( type === "error" ) {
+								complete( xhr.status, xhr.statusText );
+							} else {
+								complete(
+									xhrSuccessStatus[ xhr.status ] || xhr.status,
+									xhr.statusText,
+									// IE - #11426: When requesting binary data, IE9 will
+									// throw an exception on any attempt to access responseText
+									typeof xhr.responseText === "string" ? {
+										text: xhr.responseText
+									} : undefined,
+									xhr.getAllResponseHeaders()
+								);
 							}
 						}
-
-						// Call complete if needed
-						if ( responses ) {
-							complete( status, statusText, responses, responseHeaders );
-						}
 					};
-
-					if ( !s.async ) {
-						// if we're in sync mode we fire the callback
-						callback();
-					} else if ( xhr.readyState === 4 ) {
-						// (IE6 & IE7) if it's in cache and has been
-						// retrieved directly we need to fire the callback
-						setTimeout( callback );
-					} else {
-						handle = ++xhrId;
-						if ( xhrOnUnloadAbort ) {
-							// Create the active xhrs callbacks list if needed
-							// and attach the unload handler
-							if ( !xhrCallbacks ) {
-								xhrCallbacks = {};
-								jQuery( window ).unload( xhrOnUnloadAbort );
-							}
-							// Add to list of active xhrs callbacks
-							xhrCallbacks[ handle ] = callback;
-						}
-						xhr.onreadystatechange = callback;
-					}
-				},
-
-				abort: function() {
-					if ( callback ) {
-						callback( undefined, true );
-					}
+				};
+				// Listen to events
+				xhr.onload = callback();
+				xhr.onerror = callback("error");
+				// Create the abort callback
+				callback = callback("abort");
+				// Do send the request
+				// This may raise an exception which is actually
+				// handled in jQuery.ajax (so no try/catch here)
+				xhr.send( options.hasContent && options.data || null );
+			},
+
+			abort: function() {
+				if ( callback ) {
+					callback();
 				}
-			};
-		}
-	});
-}
+			}
+		};
+	}
+});