alpaca/dist/lib/jquery/src/ajax/xhr.js

Alpaca provides the easiest and fastest way to generate interactive forms for the web and mobile devices. It runs simply as HTML5 or more elaborately using Bootstrap, jQuery Mobile or jQuery UI. Alpaca uses Handlebars to process JSON schema and provide

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

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

var xhrId = 0,
	xhrCallbacks = {},
	xhrSuccessStatus = {
		// file protocol always yields status code 0, assume 200
		0: 200,
		// Support: IE9
		// #1450: sometimes IE returns 1223 when it should be 204
		1223: 204
	},
	xhrSupported = jQuery.ajaxSettings.xhr();

// Support: IE9
// Open requests must be manually aborted on unload (#5280)
// See https://support.microsoft.com/kb/2856746 for more info
if ( window.attachEvent ) {
	window.attachEvent( "onunload", function() {
		for ( var key in xhrCallbacks ) {
			xhrCallbacks[ key ]();
		}
	});
}

support.cors = !!xhrSupported && ( "withCredentials" in xhrSupported );
support.ajax = xhrSupported = !!xhrSupported;

jQuery.ajaxTransport(function( options ) {
	var callback;

	// Cross domain only allowed if supported through XMLHttpRequest
	if ( support.cors || xhrSupported && !options.crossDomain ) {
		return {
			send: function( headers, complete ) {
				var i,
					xhr = options.xhr(),
					id = ++xhrId;

				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 ) {
							delete xhrCallbacks[ id ];
							callback = xhr.onload = xhr.onerror = null;

							if ( type === "abort" ) {
								xhr.abort();
							} else if ( type === "error" ) {
								complete(
									// file: protocol always yields status 0; see #8605, #14207
									xhr.status,
									xhr.statusText
								);
							} else {
								complete(
									xhrSuccessStatus[ xhr.status ] || xhr.status,
									xhr.statusText,
									// Support: IE9
									// Accessing binary-data responseText throws an exception
									// (#11426)
									typeof xhr.responseText === "string" ? {
										text: xhr.responseText
									} : undefined,
									xhr.getAllResponseHeaders()
								);
							}
						}
					};
				};

				// Listen to events
				xhr.onload = callback();
				xhr.onerror = callback("error");

				// Create the abort callback
				callback = xhrCallbacks[ id ] = 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();
				}
			}
		};
	}
});

});