Микро обертка для выполенения XHR-запросов

xhr.js

/**
 * Микро обертка для выполенения XHR-запросов
 * @namepace window.xhr
 * @example
 *    xhr.load('/path/to', {type: 'POST'}, function (err, xhr) {
 *        // ...
 *    });
 */
(function (global) {
	'use strict';

	var _preload = {};

	function noop() {
	}

	function newXHR(req) {
		try {
			req = new global.XMLHttpRequest();
		} catch (err) {
			try {
				req = new global.ActiveXObject('Msxml2.XMLHTTP');
			} catch (err) {
				try {
					req = new global.ActiveXObject('Microsoft.XMLHTTP');
				} catch (err) {
					req = {readyState: 4, status: -1};
					req.open = req.send = noop;
				}
			}
		}

		return req;
	}


	var xhr = {
		version: '0.5.0',

		/**
		 * Вид запросов по умолчанию
		 * @type {boolean}
		 */
		async: true,

		/**
		 * Центральная обработка запросов
		 * @type {Function}
		 */
		oncomplete: null,

		/**
		 * Загрузить ресурс
		 * @param {string} url
		 * @param {Object|Function} [options]
		 * @param {Function} [callback]
		 */
		load: function (url, options, callback) {
			if (typeof options === 'function') {
				callback = options;
				options = {};
			}

			var req = newXHR(),
				async,
				startTime = new Date(),
				complete = function (err) {
					if (err || req.readyState === 4) {
						complete = noop; // затираем пустышкой

						err = err || (req.status !== 200 && req.status !== 201);

						req.duration = new Date() - startTime;
						req.onreadystatechange = null;

						callback && callback(err, req);
						xhr.oncomplete && xhr.oncomplete(err, req);
					}
				};

			options = options || {};
			async = options.async === void 0 ? this.async : options.async;

			req.url = url;
			req.onerror = function (evt) {
				req.onerror = null;
				complete(evt);
			};

			try {
				req.open(options.type || 'GET', url, async);
				req.send(null);

				if (async) {
					req.onreadystatechange = function () {
						complete();
					};
				}
				else {
					complete();
				}
			} catch (err) {
				complete(err);
			}
		},

		/**
		 * Загрузка ресурса с возможность повтора и eval для js
		 * @param {string} url
		 * @param {function} [oncomplete]
		 * @param {number} [attempt]
		 * @return {XMLHttpRequest}
		 */
		fetchResource: function (url, oncomplete, attempt) {
			var fetchResource = xhr.fetchResource;
			var filename = url.split('/').pop().replace(/(\.\w+)(\?.*)?$/, '$1');

			attempt = attempt | 0;

			return xhr.load(url, function (err, xhr) {
				var evalTime = new Date();

				xhr.error = err;
				xhr.attempt = attempt;
				xhr.filename = filename;
				xhr.filesize = (xhr.responseText || '').length;
				xhr.evalDuration = 0;

				try {
					// Eval source
					if (!err && /\.js$/.test(filename)) {
						eval.call(window, xhr.responseText + '\n//@ sourceURL=' + url);
					}
				} catch (error) {
					err = error;
					xhr.evalError = error;
				} finally {
					xhr.evalDuration = new Date() - evalTime;
				}

				if (err) {
					fetchResource.onerror && fetchResource.onerror(err, xhr);
				}

				if (err && (attempt < fetchResource.maxAttempts)) {
					// Retry
					attempt++;
					fetchResource.onretry && fetchResource.onretry(err, xhr);
					fetchResource(url, oncomplete, attempt);
				}
				else {
					oncomplete && oncomplete(err, xhr);
					fetchResource.oncomplete && fetchResource.oncomplete(err, xhr);
				}
			});
		},

		patchRequireJS: function (require) {
			require.load = function (context, moduleName, url) {
				xhr.fetchResource(url, function () {
					// todo: catch error;
					context.completeLoad(moduleName);
				});
			};
		},

		preload: function (name, url, options) {
			if (_preload[name] === void 0) {
				_preload[name] = {fns: []};
			}

			xhr.load(url, options, function (err, xhr) {
				var item = _preload[name];

				item.err = err;
				item.xhr = xhr;
				item.fns && item.fns.forEach(function (fn) {
					fn(err, xhr);
				});
				item.fns = null;
			});
		},

		wait: function (name, oncomplete) {
			var item = _preload[name];
			if (item === void 0) {
				_preload[name] = {fns: [oncomplete]};
			} else if (item.xhr === void 0) {
				_preload[name].fns.push(oncomplete);
			} else {
				oncomplete(item.err, item.xhr);
			}
		}
	};

	/**
	 * Последовательная загрузка ресурсов
	 * @param {string[]} urls
	 * @param {function} [oncomplete]
	 */
	xhr.fetchResource.series = function fetchResourceSeries(urls, oncomplete) {
		var queue = urls.slice(0); // clone

		(function _fetchNext() {
			var url = queue.shift();

			if (url) {
				xhr.fetchResource(url, function (err) {
					if (err) {
						oncomplete(err);
					} else {
						_fetchNext();
					}
				});
			} else {
				oncomplete();
			}
		})();
	};

	/**
	 * Масимальное кол-во попыток при загрузке ресурсов
	 * @type {number}
	 */
	xhr.fetchResource.maxAttempts = 2;

	// Export
	global['xhr'] = xhr;
})(window);

xhr.min.js

(function(l){function m(){}function p(a){try{a=new l.XMLHttpRequest}catch(c){try{a=new l.ActiveXObject("Msxml2.XMLHTTP")}catch(d){try{a=new l.ActiveXObject("Microsoft.XMLHTTP")}catch(b){a={readyState:4,status:-1},a.open=a.send=m}}}return a}var h={},g={version:"0.5.0",async:!0,oncomplete:null,load:function(a,c,d){"function"===typeof c&&(d=c,c={});var b=p(),k=new Date,e=function(a){if(a||4===b.readyState)e=m,a=a||200!==b.status&&201!==b.status,b.duration=new Date-k,b.onreadystatechange=null,d&&d(a,
b),g.oncomplete&&g.oncomplete(a,b)};c=c||{};var f=void 0===c.async?this.async:c.async;b.url=a;b.onerror=function(a){b.onerror=null;e(a)};try{b.open(c.type||"GET",a,f),b.send(null),f?b.onreadystatechange=function(){e()}:e()}catch(q){e(q)}},fetchResource:function(a,c,d){var b=g.fetchResource,k=a.split("/").pop().replace(/(\.\w+)(\?.*)?$/,"$1");d|=0;return g.load(a,function(e,f){var g=new Date;f.error=e;f.attempt=d;f.filename=k;f.filesize=(f.responseText||"").length;f.evalDuration=0;try{!e&&/\.js$/.test(k)&&
eval.call(window,f.responseText+"\n//@ sourceURL="+a)}catch(n){e=n,f.evalError=n}finally{f.evalDuration=new Date-g}e&&b.onerror&&b.onerror(e,f);e&&d<b.maxAttempts?(d++,b.onretry&&b.onretry(e,f),b(a,c,d)):(c&&c(e,f),b.oncomplete&&b.oncomplete(e,f))})},patchRequireJS:function(a){a.load=function(a,d,b){g.fetchResource(b,function(){a.completeLoad(d)})}},preload:function(a,c,d){void 0===h[a]&&(h[a]={fns:[]});g.load(c,d,function(b,c){var e=h[a];e.err=b;e.xhr=c;e.fns&&e.fns.forEach(function(a){a(b,c)});
e.fns=null})},wait:function(a,c){var d=h[a];void 0===d?h[a]={fns:[c]}:void 0===d.xhr?h[a].fns.push(c):c(d.err,d.xhr)}};g.fetchResource.series=function(a,c){var d=a.slice(0);(function k(){var a=d.shift();a?g.fetchResource(a,function(a){a?c(a):k()}):c()})()};g.fetchResource.maxAttempts=2;l.xhr=g})(window);

xhr.open может бросить исключение. Нужен try/catch для req.open(options.type || 'GET', url, async);

Да, точно, поправил.