| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| /** Creates a new function to forward a call. |
| * @param {Object} thisValue - Value to use as the 'this' object. |
| * @param {String} name - Name of function to forward to. |
| * @param {Object} returnValue - Return value for the forward call (helps keep identity when chaining calls). |
| * @returns {Function} A new function that will forward a call. |
| */ |
| var forwardCall = function (thisValue, name, returnValue) { |
| return function () { |
| thisValue[name].apply(thisValue, arguments); |
| return returnValue; |
| }; |
| }; |
| |
| /** Initializes a new DjsDeferred object. |
| * Compability Note A - Ordering of callbacks through chained 'then' invocations |
| * |
| * The Wiki entry at http://wiki.commonjs.org/wiki/Promises/A |
| * implies that .then() returns a distinct object. |
| * |
| * For compatibility with http://api.jquery.com/category/deferred-object/ |
| * we return this same object. This affects ordering, as |
| * the jQuery version will fire callbacks in registration |
| * order regardless of whether they occur on the result |
| * or the original object. |
| * |
| * Compability Note B - Fulfillment value |
| * |
| * The Wiki entry at http://wiki.commonjs.org/wiki/Promises/A |
| * implies that the result of a success callback is the |
| * fulfillment value of the object and is received by |
| * other success callbacks that are chained. |
| * |
| * For compatibility with http://api.jquery.com/category/deferred-object/ |
| * we disregard this value instead. |
| */ |
| var DjsDeferred = function () { |
| this._arguments = undefined; |
| this._done = undefined; |
| this._fail = undefined; |
| this._resolved = false; |
| this._rejected = false; |
| }; |
| |
| |
| DjsDeferred.prototype = { |
| |
| /** Adds success and error callbacks for this deferred object. |
| * @param {function} [fulfilledHandler] - Success callback ( may be null) |
| * @param {function} [errorHandler] - Error callback ( may be null) |
| * See Compatibility Note A. |
| */ |
| then: function (fulfilledHandler, errorHandler) { |
| |
| if (fulfilledHandler) { |
| if (!this._done) { |
| this._done = [fulfilledHandler]; |
| } else { |
| this._done.push(fulfilledHandler); |
| } |
| } |
| |
| if (errorHandler) { |
| if (!this._fail) { |
| this._fail = [errorHandler]; |
| } else { |
| this._fail.push(errorHandler); |
| } |
| } |
| |
| //// See Compatibility Note A in the DjsDeferred constructor. |
| //// if (!this._next) { |
| //// this._next = createDeferred(); |
| //// } |
| //// return this._next.promise(); |
| |
| if (this._resolved) { |
| this.resolve.apply(this, this._arguments); |
| } else if (this._rejected) { |
| this.reject.apply(this, this._arguments); |
| } |
| |
| return this; |
| }, |
| |
| /** Invokes success callbacks for this deferred object. |
| *All arguments are forwarded to success callbacks. |
| */ |
| resolve: function (/* args */) { |
| if (this._done) { |
| var i, len; |
| for (i = 0, len = this._done.length; i < len; i++) { |
| //// See Compability Note B - Fulfillment value. |
| //// var nextValue = |
| this._done[i].apply(null, arguments); |
| } |
| |
| //// See Compatibility Note A in the DjsDeferred constructor. |
| //// this._next.resolve(nextValue); |
| //// delete this._next; |
| |
| this._done = undefined; |
| this._resolved = false; |
| this._arguments = undefined; |
| } else { |
| this._resolved = true; |
| this._arguments = arguments; |
| } |
| }, |
| |
| /** Invokes error callbacks for this deferred object. |
| * All arguments are forwarded to error callbacks. |
| */ |
| reject: function (/* args */) { |
| |
| if (this._fail) { |
| var i, len; |
| for (i = 0, len = this._fail.length; i < len; i++) { |
| this._fail[i].apply(null, arguments); |
| } |
| |
| this._fail = undefined; |
| this._rejected = false; |
| this._arguments = undefined; |
| } else { |
| this._rejected = true; |
| this._arguments = arguments; |
| } |
| }, |
| |
| /** Returns a version of this object that has only the read-only methods available. |
| * @returns An object with only the promise object. |
| */ |
| promise: function () { |
| var result = {}; |
| result.then = forwardCall(this, "then", result); |
| return result; |
| } |
| }; |
| |
| /** Creates a deferred object. |
| * @returns {DjsDeferred} A new deferred object. If jQuery is installed, then a jQueryDeferred object is returned, which provides a superset of features. |
| */ |
| var createDeferred = function () { |
| |
| |
| if (window.jQuery && window.jQuery.Deferred) { |
| return new window.jQuery.Deferred(); |
| } else { |
| return new DjsDeferred(); |
| } |
| }; |
| |
| exports.createDeferred = createDeferred; |
| exports.DjsDeferred = DjsDeferred; |
| |