define( [

  	"../core",
  	"../var/support",
  	"../ajax"
  ], function( jQuery, support ) {

  "use strict";

  jQuery.ajaxSettings.xhr = function() {
  	try {
  		return new window.XMLHttpRequest();
  	} catch ( e ) {}
  };

  var xhrSuccessStatus = {

  		// File protocol always yields status code 0, assume 200
  		0: 200,

  		// Support: IE <=9 only
  		// #1450: sometimes IE returns 1223 when it should be 204
  		1223: 204
  	},
  	xhrSupported = jQuery.ajaxSettings.xhr();

  support.cors = !!xhrSupported && ( "withCredentials" in xhrSupported );
  support.ajax = xhrSupported = !!xhrSupported;
  
  jQuery.ajaxTransport( function( options ) {
  	var callback, errorCallback;
  
  	// Cross domain only allowed if supported through XMLHttpRequest
  	if ( support.cors || xhrSupported && !options.crossDomain ) {
  		return {
  			send: function( headers, complete ) {
  				var i,
  					xhr = options.xhr();
  
  				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 ];

  					}

  				}

  				// 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 = errorCallback = xhr.onload =
  								xhr.onerror = xhr.onabort = xhr.onreadystatechange = null;
  
  							if ( type === "abort" ) {
  								xhr.abort();
  							} else if ( type === "error" ) {
  
  								// Support: IE <=9 only
  								// On a manual native abort, IE9 throws
  								// errors on any property access that is not readyState
  								if ( typeof xhr.status !== "number" ) {
  									complete( 0, "error" );
  								} else {
  									complete(
  
  										// File: protocol always yields status 0; see #8605, #14207
  										xhr.status,
  										xhr.statusText
  									);

  								}
  							} else {

  								complete(
  									xhrSuccessStatus[ xhr.status ] || xhr.status,
  									xhr.statusText,
  
  									// Support: IE <=9 only
  									// IE9 has no XHR2 but throws on binary (trac-11426)
  									// For XHR2 non-text, let the caller handle it (gh-2498)
  									( xhr.responseType || "text" ) !== "text"  ||
  									typeof xhr.responseText !== "string" ?
  										{ binary: xhr.response } :
  										{ text: xhr.responseText },
  									xhr.getAllResponseHeaders()
  								);

  							}
  						}

  					};
  				};
  
  				// Listen to events
  				xhr.onload = callback();
  				errorCallback = xhr.onerror = callback( "error" );
  
  				// Support: IE 9 only
  				// Use onreadystatechange to replace onabort
  				// to handle uncaught aborts
  				if ( xhr.onabort !== undefined ) {
  					xhr.onabort = errorCallback;
  				} else {
  					xhr.onreadystatechange = function() {
  
  						// Check readyState before timeout as it changes
  						if ( xhr.readyState === 4 ) {
  
  							// Allow onerror to be called first,
  							// but that will not handle a native abort
  							// Also, save errorCallback to a variable
  							// as xhr.onerror cannot be accessed
  							window.setTimeout( function() {
  								if ( callback ) {
  									errorCallback();
  								}
  							} );

  						}
  					};

  				}

  				// Create the abort callback
  				callback = callback( "abort" );
  
  				try {

  					// Do send the request (this may raise an exception)
  					xhr.send( options.hasContent && options.data || null );
  				} catch ( e ) {
  
  					// #14683: Only rethrow if this hasn't been notified as an error yet

  					if ( callback ) {

  						throw e;

  					}
  				}

  			},

  			abort: function() {
  				if ( callback ) {
  					callback();
  				}
  			}
  		};
  	}
  } );

  } );