dojo_app/js/library/dojo/request/handlers.js

define([
	'../json',
	'../_base/kernel',
	'../_base/array',
	'../has',
	'../has!dom?../selector/_loader' // only included for has() qsa tests
], function(JSON, kernel, array, has){
	has.add('activex', typeof ActiveXObject !== 'undefined');
	has.add('dom-parser', function(global){
		return 'DOMParser' in global;
	});

	var handleXML;
	if(has('activex')){
		// GUIDs obtained from http://msdn.microsoft.com/en-us/library/ms757837(VS.85).aspx
		var dp = [
			'Msxml2.DOMDocument.6.0',
			'Msxml2.DOMDocument.4.0',
			'MSXML2.DOMDocument.3.0',
			'MSXML.DOMDocument' // 2.0
		];
		var lastParser;

		handleXML = function(response){
			var result = response.data;
			var text = response.text;

			if(result && has('dom-qsa2.1') && !result.querySelectorAll && has('dom-parser')){
				// http://bugs.dojotoolkit.org/ticket/15631
				// IE9 supports a CSS3 querySelectorAll implementation, but the DOM implementation
				// returned by IE9 xhr.responseXML does not. Manually create the XML DOM to gain
				// the fuller-featured implementation and avoid bugs caused by the inconsistency
				result = new DOMParser().parseFromString(text, 'application/xml');
			}

			function createDocument(p) {
					try{
						var dom = new ActiveXObject(p);
						dom.async = false;
						dom.loadXML(text);
						result = dom;
						lastParser = p;
					}catch(e){ return false; }
					return true;
			}

			if(!result || !result.documentElement){
				// The creation of an ActiveX object is expensive, so we cache the
				// parser type to avoid trying all parser types each time we handle a
				// document. There is some concern that some parser types might fail
				// depending on the document being parsed. If parsing using the cached
				// parser type fails, we do the more expensive operation of finding one
				// that works for the given document.
				// https://bugs.dojotoolkit.org/ticket/15246
				if(!lastParser || !createDocument(lastParser)) {
					array.some(dp, createDocument);
				}
			}

			return result;
		};
	}

	var handleNativeResponse = function(response) {
		if(!has('native-xhr2-blob') && response.options.handleAs === 'blob' && typeof Blob !== 'undefined'){
			return new Blob([ response.xhr.response ], { type: response.xhr.getResponseHeader('Content-Type') });
		}

		return response.xhr.response;
	}

	var handlers = {
		'javascript': function(response){
			return kernel.eval(response.text || '');
		},
		'json': function(response){
			return JSON.parse(response.text || null);
		},
		'xml': handleXML,
		'blob': handleNativeResponse,
		'arraybuffer': handleNativeResponse,
		'document': handleNativeResponse
	};

	function handle(response){
		var handler = handlers[response.options.handleAs];

		response.data = handler ? handler(response) : (response.data || response.text);

		return response;
	}

	handle.register = function(name, handler){
		handlers[name] = handler;
	};

	return handle;
});