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Diffstat (limited to 'catapult/third_party/polymer/components/promise-polyfill/Promise.js')
-rw-r--r-- | catapult/third_party/polymer/components/promise-polyfill/Promise.js | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/catapult/third_party/polymer/components/promise-polyfill/Promise.js b/catapult/third_party/polymer/components/promise-polyfill/Promise.js new file mode 100644 index 00000000..b8388bf3 --- /dev/null +++ b/catapult/third_party/polymer/components/promise-polyfill/Promise.js @@ -0,0 +1,137 @@ +/** +@license +Copyright (c) 2016 The Polymer Project Authors. All rights reserved. +This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt +The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt +The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt +Code distributed by Google as part of the polymer project is also +subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt +*/ +function MakePromise (asap) { + function Promise(fn) { + if (typeof this !== 'object' || typeof fn !== 'function') throw new TypeError(); + this._state = null; + this._value = null; + this._deferreds = [] + + doResolve(fn, resolve.bind(this), reject.bind(this)); + } + + function handle(deferred) { + var me = this; + if (this._state === null) { + this._deferreds.push(deferred); + return + } + asap(function() { + var cb = me._state ? deferred.onFulfilled : deferred.onRejected + if (typeof cb !== 'function') { + (me._state ? deferred.resolve : deferred.reject)(me._value); + return; + } + var ret; + try { + ret = cb(me._value); + } + catch (e) { + deferred.reject(e); + return; + } + deferred.resolve(ret); + }) + } + + function resolve(newValue) { + try { //Promise Resolution Procedure: https://github.com/promises-aplus/promises-spec#the-promise-resolution-procedure + if (newValue === this) throw new TypeError(); + if (newValue && (typeof newValue === 'object' || typeof newValue === 'function')) { + var then = newValue.then; + if (typeof then === 'function') { + doResolve(then.bind(newValue), resolve.bind(this), reject.bind(this)); + return; + } + } + this._state = true; + this._value = newValue; + finale.call(this); + } catch (e) { reject.call(this, e); } + } + + function reject(newValue) { + this._state = false; + this._value = newValue; + finale.call(this); + } + + function finale() { + for (var i = 0, len = this._deferreds.length; i < len; i++) { + handle.call(this, this._deferreds[i]); + } + this._deferreds = null; + } + + /** + * Take a potentially misbehaving resolver function and make sure + * onFulfilled and onRejected are only called once. + * + * Makes no guarantees about asynchrony. + */ + function doResolve(fn, onFulfilled, onRejected) { + var done = false; + try { + fn(function (value) { + if (done) return; + done = true; + onFulfilled(value); + }, function (reason) { + if (done) return; + done = true; + onRejected(reason); + }) + } catch (ex) { + if (done) return; + done = true; + onRejected(ex); + } + } + + Promise.prototype['catch'] = function (onRejected) { + return this.then(null, onRejected); + }; + + Promise.prototype.then = function(onFulfilled, onRejected) { + var me = this; + return new Promise(function(resolve, reject) { + handle.call(me, { + onFulfilled: onFulfilled, + onRejected: onRejected, + resolve: resolve, + reject: reject + }); + }) + }; + + Promise.resolve = function (value) { + if (value && typeof value === 'object' && value.constructor === Promise) { + return value; + } + + return new Promise(function (resolve) { + resolve(value); + }); + }; + + Promise.reject = function (value) { + return new Promise(function (resolve, reject) { + reject(value); + }); + }; + + + return Promise; +} + +if (typeof module !== 'undefined') { + module.exports = MakePromise; +} + |