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- /*!
- * @overview es6-promise - a tiny implementation of Promises/A+.
- * @copyright Copyright (c) 2014 Yehuda Katz, Tom Dale, Stefan Penner and contributors (Conversion to ES6 API by Jake Archibald)
- * @license Licensed under MIT license
- * See https://raw.githubusercontent.com/stefanpenner/es6-promise/master/LICENSE
- * @version 3.3.1
- */
- (function (global, factory) {
- typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
- typeof define === 'function' && define.amd ? define(factory) :
- (global.ES6Promise = factory());
- }(this, (function () { 'use strict';
- function objectOrFunction(x) {
- return typeof x === 'function' || typeof x === 'object' && x !== null;
- }
- function isFunction(x) {
- return typeof x === 'function';
- }
- var _isArray = undefined;
- if (!Array.isArray) {
- _isArray = function (x) {
- return Object.prototype.toString.call(x) === '[object Array]';
- };
- } else {
- _isArray = Array.isArray;
- }
- var isArray = _isArray;
- var len = 0;
- var vertxNext = undefined;
- var customSchedulerFn = undefined;
- var asap = function asap(callback, arg) {
- queue[len] = callback;
- queue[len + 1] = arg;
- len += 2;
- if (len === 2) {
- // If len is 2, that means that we need to schedule an async flush.
- // If additional callbacks are queued before the queue is flushed, they
- // will be processed by this flush that we are scheduling.
- if (customSchedulerFn) {
- customSchedulerFn(flush);
- } else {
- scheduleFlush();
- }
- }
- };
- function setScheduler(scheduleFn) {
- customSchedulerFn = scheduleFn;
- }
- function setAsap(asapFn) {
- asap = asapFn;
- }
- var browserWindow = typeof window !== 'undefined' ? window : undefined;
- var browserGlobal = browserWindow || {};
- var BrowserMutationObserver = browserGlobal.MutationObserver || browserGlobal.WebKitMutationObserver;
- var isNode = typeof self === 'undefined' && typeof process !== 'undefined' && ({}).toString.call(process) === '[object process]';
- // test for web worker but not in IE10
- var isWorker = typeof Uint8ClampedArray !== 'undefined' && typeof importScripts !== 'undefined' && typeof MessageChannel !== 'undefined';
- // node
- function useNextTick() {
- // node version 0.10.x displays a deprecation warning when nextTick is used recursively
- // see https://github.com/cujojs/when/issues/410 for details
- return function () {
- return process.nextTick(flush);
- };
- }
- // vertx
- function useVertxTimer() {
- return function () {
- vertxNext(flush);
- };
- }
- function useMutationObserver() {
- var iterations = 0;
- var observer = new BrowserMutationObserver(flush);
- var node = document.createTextNode('');
- observer.observe(node, { characterData: true });
- return function () {
- node.data = iterations = ++iterations % 2;
- };
- }
- // web worker
- function useMessageChannel() {
- var channel = new MessageChannel();
- channel.port1.onmessage = flush;
- return function () {
- return channel.port2.postMessage(0);
- };
- }
- function useSetTimeout() {
- // Store setTimeout reference so es6-promise will be unaffected by
- // other code modifying setTimeout (like sinon.useFakeTimers())
- var globalSetTimeout = setTimeout;
- return function () {
- return globalSetTimeout(flush, 1);
- };
- }
- var queue = new Array(1000);
- function flush() {
- for (var i = 0; i < len; i += 2) {
- var callback = queue[i];
- var arg = queue[i + 1];
- callback(arg);
- queue[i] = undefined;
- queue[i + 1] = undefined;
- }
- len = 0;
- }
- function attemptVertx() {
- try {
- var r = require;
- var vertx = r('vertx');
- vertxNext = vertx.runOnLoop || vertx.runOnContext;
- return useVertxTimer();
- } catch (e) {
- return useSetTimeout();
- }
- }
- var scheduleFlush = undefined;
- // Decide what async method to use to triggering processing of queued callbacks:
- if (isNode) {
- scheduleFlush = useNextTick();
- } else if (BrowserMutationObserver) {
- scheduleFlush = useMutationObserver();
- } else if (isWorker) {
- scheduleFlush = useMessageChannel();
- } else if (browserWindow === undefined && typeof require === 'function') {
- scheduleFlush = attemptVertx();
- } else {
- scheduleFlush = useSetTimeout();
- }
- function then(onFulfillment, onRejection) {
- var _arguments = arguments;
- var parent = this;
- var child = new this.constructor(noop);
- if (child[PROMISE_ID] === undefined) {
- makePromise(child);
- }
- var _state = parent._state;
- if (_state) {
- (function () {
- var callback = _arguments[_state - 1];
- asap(function () {
- return invokeCallback(_state, child, callback, parent._result);
- });
- })();
- } else {
- subscribe(parent, child, onFulfillment, onRejection);
- }
- return child;
- }
- /**
- `Promise.resolve` returns a promise that will become resolved with the
- passed `value`. It is shorthand for the following:
- ```javascript
- let promise = new Promise(function(resolve, reject){
- resolve(1);
- });
- promise.then(function(value){
- // value === 1
- });
- ```
- Instead of writing the above, your code now simply becomes the following:
- ```javascript
- let promise = Promise.resolve(1);
- promise.then(function(value){
- // value === 1
- });
- ```
- @method resolve
- @static
- @param {Any} value value that the returned promise will be resolved with
- Useful for tooling.
- @return {Promise} a promise that will become fulfilled with the given
- `value`
- */
- function resolve(object) {
- /*jshint validthis:true */
- var Constructor = this;
- if (object && typeof object === 'object' && object.constructor === Constructor) {
- return object;
- }
- var promise = new Constructor(noop);
- _resolve(promise, object);
- return promise;
- }
- var PROMISE_ID = Math.random().toString(36).substring(16);
- function noop() {}
- var PENDING = void 0;
- var FULFILLED = 1;
- var REJECTED = 2;
- var GET_THEN_ERROR = new ErrorObject();
- function selfFulfillment() {
- return new TypeError("You cannot resolve a promise with itself");
- }
- function cannotReturnOwn() {
- return new TypeError('A promises callback cannot return that same promise.');
- }
- function getThen(promise) {
- try {
- return promise.then;
- } catch (error) {
- GET_THEN_ERROR.error = error;
- return GET_THEN_ERROR;
- }
- }
- function tryThen(then, value, fulfillmentHandler, rejectionHandler) {
- try {
- then.call(value, fulfillmentHandler, rejectionHandler);
- } catch (e) {
- return e;
- }
- }
- function handleForeignThenable(promise, thenable, then) {
- asap(function (promise) {
- var sealed = false;
- var error = tryThen(then, thenable, function (value) {
- if (sealed) {
- return;
- }
- sealed = true;
- if (thenable !== value) {
- _resolve(promise, value);
- } else {
- fulfill(promise, value);
- }
- }, function (reason) {
- if (sealed) {
- return;
- }
- sealed = true;
- _reject(promise, reason);
- }, 'Settle: ' + (promise._label || ' unknown promise'));
- if (!sealed && error) {
- sealed = true;
- _reject(promise, error);
- }
- }, promise);
- }
- function handleOwnThenable(promise, thenable) {
- if (thenable._state === FULFILLED) {
- fulfill(promise, thenable._result);
- } else if (thenable._state === REJECTED) {
- _reject(promise, thenable._result);
- } else {
- subscribe(thenable, undefined, function (value) {
- return _resolve(promise, value);
- }, function (reason) {
- return _reject(promise, reason);
- });
- }
- }
- function handleMaybeThenable(promise, maybeThenable, then$$) {
- if (maybeThenable.constructor === promise.constructor && then$$ === then && maybeThenable.constructor.resolve === resolve) {
- handleOwnThenable(promise, maybeThenable);
- } else {
- if (then$$ === GET_THEN_ERROR) {
- _reject(promise, GET_THEN_ERROR.error);
- } else if (then$$ === undefined) {
- fulfill(promise, maybeThenable);
- } else if (isFunction(then$$)) {
- handleForeignThenable(promise, maybeThenable, then$$);
- } else {
- fulfill(promise, maybeThenable);
- }
- }
- }
- function _resolve(promise, value) {
- if (promise === value) {
- _reject(promise, selfFulfillment());
- } else if (objectOrFunction(value)) {
- handleMaybeThenable(promise, value, getThen(value));
- } else {
- fulfill(promise, value);
- }
- }
- function publishRejection(promise) {
- if (promise._onerror) {
- promise._onerror(promise._result);
- }
- publish(promise);
- }
- function fulfill(promise, value) {
- if (promise._state !== PENDING) {
- return;
- }
- promise._result = value;
- promise._state = FULFILLED;
- if (promise._subscribers.length !== 0) {
- asap(publish, promise);
- }
- }
- function _reject(promise, reason) {
- if (promise._state !== PENDING) {
- return;
- }
- promise._state = REJECTED;
- promise._result = reason;
- asap(publishRejection, promise);
- }
- function subscribe(parent, child, onFulfillment, onRejection) {
- var _subscribers = parent._subscribers;
- var length = _subscribers.length;
- parent._onerror = null;
- _subscribers[length] = child;
- _subscribers[length + FULFILLED] = onFulfillment;
- _subscribers[length + REJECTED] = onRejection;
- if (length === 0 && parent._state) {
- asap(publish, parent);
- }
- }
- function publish(promise) {
- var subscribers = promise._subscribers;
- var settled = promise._state;
- if (subscribers.length === 0) {
- return;
- }
- var child = undefined,
- callback = undefined,
- detail = promise._result;
- for (var i = 0; i < subscribers.length; i += 3) {
- child = subscribers[i];
- callback = subscribers[i + settled];
- if (child) {
- invokeCallback(settled, child, callback, detail);
- } else {
- callback(detail);
- }
- }
- promise._subscribers.length = 0;
- }
- function ErrorObject() {
- this.error = null;
- }
- var TRY_CATCH_ERROR = new ErrorObject();
- function tryCatch(callback, detail) {
- try {
- return callback(detail);
- } catch (e) {
- TRY_CATCH_ERROR.error = e;
- return TRY_CATCH_ERROR;
- }
- }
- function invokeCallback(settled, promise, callback, detail) {
- var hasCallback = isFunction(callback),
- value = undefined,
- error = undefined,
- succeeded = undefined,
- failed = undefined;
- if (hasCallback) {
- value = tryCatch(callback, detail);
- if (value === TRY_CATCH_ERROR) {
- failed = true;
- error = value.error;
- value = null;
- } else {
- succeeded = true;
- }
- if (promise === value) {
- _reject(promise, cannotReturnOwn());
- return;
- }
- } else {
- value = detail;
- succeeded = true;
- }
- if (promise._state !== PENDING) {
- // noop
- } else if (hasCallback && succeeded) {
- _resolve(promise, value);
- } else if (failed) {
- _reject(promise, error);
- } else if (settled === FULFILLED) {
- fulfill(promise, value);
- } else if (settled === REJECTED) {
- _reject(promise, value);
- }
- }
- function initializePromise(promise, resolver) {
- try {
- resolver(function resolvePromise(value) {
- _resolve(promise, value);
- }, function rejectPromise(reason) {
- _reject(promise, reason);
- });
- } catch (e) {
- _reject(promise, e);
- }
- }
- var id = 0;
- function nextId() {
- return id++;
- }
- function makePromise(promise) {
- promise[PROMISE_ID] = id++;
- promise._state = undefined;
- promise._result = undefined;
- promise._subscribers = [];
- }
- function Enumerator(Constructor, input) {
- this._instanceConstructor = Constructor;
- this.promise = new Constructor(noop);
- if (!this.promise[PROMISE_ID]) {
- makePromise(this.promise);
- }
- if (isArray(input)) {
- this._input = input;
- this.length = input.length;
- this._remaining = input.length;
- this._result = new Array(this.length);
- if (this.length === 0) {
- fulfill(this.promise, this._result);
- } else {
- this.length = this.length || 0;
- this._enumerate();
- if (this._remaining === 0) {
- fulfill(this.promise, this._result);
- }
- }
- } else {
- _reject(this.promise, validationError());
- }
- }
- function validationError() {
- return new Error('Array Methods must be provided an Array');
- };
- Enumerator.prototype._enumerate = function () {
- var length = this.length;
- var _input = this._input;
- for (var i = 0; this._state === PENDING && i < length; i++) {
- this._eachEntry(_input[i], i);
- }
- };
- Enumerator.prototype._eachEntry = function (entry, i) {
- var c = this._instanceConstructor;
- var resolve$$ = c.resolve;
- if (resolve$$ === resolve) {
- var _then = getThen(entry);
- if (_then === then && entry._state !== PENDING) {
- this._settledAt(entry._state, i, entry._result);
- } else if (typeof _then !== 'function') {
- this._remaining--;
- this._result[i] = entry;
- } else if (c === Promise) {
- var promise = new c(noop);
- handleMaybeThenable(promise, entry, _then);
- this._willSettleAt(promise, i);
- } else {
- this._willSettleAt(new c(function (resolve$$) {
- return resolve$$(entry);
- }), i);
- }
- } else {
- this._willSettleAt(resolve$$(entry), i);
- }
- };
- Enumerator.prototype._settledAt = function (state, i, value) {
- var promise = this.promise;
- if (promise._state === PENDING) {
- this._remaining--;
- if (state === REJECTED) {
- _reject(promise, value);
- } else {
- this._result[i] = value;
- }
- }
- if (this._remaining === 0) {
- fulfill(promise, this._result);
- }
- };
- Enumerator.prototype._willSettleAt = function (promise, i) {
- var enumerator = this;
- subscribe(promise, undefined, function (value) {
- return enumerator._settledAt(FULFILLED, i, value);
- }, function (reason) {
- return enumerator._settledAt(REJECTED, i, reason);
- });
- };
- /**
- `Promise.all` accepts an array of promises, and returns a new promise which
- is fulfilled with an array of fulfillment values for the passed promises, or
- rejected with the reason of the first passed promise to be rejected. It casts all
- elements of the passed iterable to promises as it runs this algorithm.
- Example:
- ```javascript
- let promise1 = resolve(1);
- let promise2 = resolve(2);
- let promise3 = resolve(3);
- let promises = [ promise1, promise2, promise3 ];
- Promise.all(promises).then(function(array){
- // The array here would be [ 1, 2, 3 ];
- });
- ```
- If any of the `promises` given to `all` are rejected, the first promise
- that is rejected will be given as an argument to the returned promises's
- rejection handler. For example:
- Example:
- ```javascript
- let promise1 = resolve(1);
- let promise2 = reject(new Error("2"));
- let promise3 = reject(new Error("3"));
- let promises = [ promise1, promise2, promise3 ];
- Promise.all(promises).then(function(array){
- // Code here never runs because there are rejected promises!
- }, function(error) {
- // error.message === "2"
- });
- ```
- @method all
- @static
- @param {Array} entries array of promises
- @param {String} label optional string for labeling the promise.
- Useful for tooling.
- @return {Promise} promise that is fulfilled when all `promises` have been
- fulfilled, or rejected if any of them become rejected.
- @static
- */
- function all(entries) {
- return new Enumerator(this, entries).promise;
- }
- /**
- `Promise.race` returns a new promise which is settled in the same way as the
- first passed promise to settle.
- Example:
- ```javascript
- let promise1 = new Promise(function(resolve, reject){
- setTimeout(function(){
- resolve('promise 1');
- }, 200);
- });
- let promise2 = new Promise(function(resolve, reject){
- setTimeout(function(){
- resolve('promise 2');
- }, 100);
- });
- Promise.race([promise1, promise2]).then(function(result){
- // result === 'promise 2' because it was resolved before promise1
- // was resolved.
- });
- ```
- `Promise.race` is deterministic in that only the state of the first
- settled promise matters. For example, even if other promises given to the
- `promises` array argument are resolved, but the first settled promise has
- become rejected before the other promises became fulfilled, the returned
- promise will become rejected:
- ```javascript
- let promise1 = new Promise(function(resolve, reject){
- setTimeout(function(){
- resolve('promise 1');
- }, 200);
- });
- let promise2 = new Promise(function(resolve, reject){
- setTimeout(function(){
- reject(new Error('promise 2'));
- }, 100);
- });
- Promise.race([promise1, promise2]).then(function(result){
- // Code here never runs
- }, function(reason){
- // reason.message === 'promise 2' because promise 2 became rejected before
- // promise 1 became fulfilled
- });
- ```
- An example real-world use case is implementing timeouts:
- ```javascript
- Promise.race([ajax('foo.json'), timeout(5000)])
- ```
- @method race
- @static
- @param {Array} promises array of promises to observe
- Useful for tooling.
- @return {Promise} a promise which settles in the same way as the first passed
- promise to settle.
- */
- function race(entries) {
- /*jshint validthis:true */
- var Constructor = this;
- if (!isArray(entries)) {
- return new Constructor(function (_, reject) {
- return reject(new TypeError('You must pass an array to race.'));
- });
- } else {
- return new Constructor(function (resolve, reject) {
- var length = entries.length;
- for (var i = 0; i < length; i++) {
- Constructor.resolve(entries[i]).then(resolve, reject);
- }
- });
- }
- }
- /**
- `Promise.reject` returns a promise rejected with the passed `reason`.
- It is shorthand for the following:
- ```javascript
- let promise = new Promise(function(resolve, reject){
- reject(new Error('WHOOPS'));
- });
- promise.then(function(value){
- // Code here doesn't run because the promise is rejected!
- }, function(reason){
- // reason.message === 'WHOOPS'
- });
- ```
- Instead of writing the above, your code now simply becomes the following:
- ```javascript
- let promise = Promise.reject(new Error('WHOOPS'));
- promise.then(function(value){
- // Code here doesn't run because the promise is rejected!
- }, function(reason){
- // reason.message === 'WHOOPS'
- });
- ```
- @method reject
- @static
- @param {Any} reason value that the returned promise will be rejected with.
- Useful for tooling.
- @return {Promise} a promise rejected with the given `reason`.
- */
- function reject(reason) {
- /*jshint validthis:true */
- var Constructor = this;
- var promise = new Constructor(noop);
- _reject(promise, reason);
- return promise;
- }
- function needsResolver() {
- throw new TypeError('You must pass a resolver function as the first argument to the promise constructor');
- }
- function needsNew() {
- throw new TypeError("Failed to construct 'Promise': Please use the 'new' operator, this object constructor cannot be called as a function.");
- }
- /**
- Promise objects represent the eventual result of an asynchronous operation. The
- primary way of interacting with a promise is through its `then` method, which
- registers callbacks to receive either a promise's eventual value or the reason
- why the promise cannot be fulfilled.
- Terminology
- -----------
- - `promise` is an object or function with a `then` method whose behavior conforms to this specification.
- - `thenable` is an object or function that defines a `then` method.
- - `value` is any legal JavaScript value (including undefined, a thenable, or a promise).
- - `exception` is a value that is thrown using the throw statement.
- - `reason` is a value that indicates why a promise was rejected.
- - `settled` the final resting state of a promise, fulfilled or rejected.
- A promise can be in one of three states: pending, fulfilled, or rejected.
- Promises that are fulfilled have a fulfillment value and are in the fulfilled
- state. Promises that are rejected have a rejection reason and are in the
- rejected state. A fulfillment value is never a thenable.
- Promises can also be said to *resolve* a value. If this value is also a
- promise, then the original promise's settled state will match the value's
- settled state. So a promise that *resolves* a promise that rejects will
- itself reject, and a promise that *resolves* a promise that fulfills will
- itself fulfill.
- Basic Usage:
- ------------
- ```js
- let promise = new Promise(function(resolve, reject) {
- // on success
- resolve(value);
- // on failure
- reject(reason);
- });
- promise.then(function(value) {
- // on fulfillment
- }, function(reason) {
- // on rejection
- });
- ```
- Advanced Usage:
- ---------------
- Promises shine when abstracting away asynchronous interactions such as
- `XMLHttpRequest`s.
- ```js
- function getJSON(url) {
- return new Promise(function(resolve, reject){
- let xhr = new XMLHttpRequest();
- xhr.open('GET', url);
- xhr.onreadystatechange = handler;
- xhr.responseType = 'json';
- xhr.setRequestHeader('Accept', 'application/json');
- xhr.send();
- function handler() {
- if (this.readyState === this.DONE) {
- if (this.status === 200) {
- resolve(this.response);
- } else {
- reject(new Error('getJSON: `' + url + '` failed with status: [' + this.status + ']'));
- }
- }
- };
- });
- }
- getJSON('/posts.json').then(function(json) {
- // on fulfillment
- }, function(reason) {
- // on rejection
- });
- ```
- Unlike callbacks, promises are great composable primitives.
- ```js
- Promise.all([
- getJSON('/posts'),
- getJSON('/comments')
- ]).then(function(values){
- values[0] // => postsJSON
- values[1] // => commentsJSON
- return values;
- });
- ```
- @class Promise
- @param {function} resolver
- Useful for tooling.
- @constructor
- */
- function Promise(resolver) {
- this[PROMISE_ID] = nextId();
- this._result = this._state = undefined;
- this._subscribers = [];
- if (noop !== resolver) {
- typeof resolver !== 'function' && needsResolver();
- this instanceof Promise ? initializePromise(this, resolver) : needsNew();
- }
- }
- Promise.all = all;
- Promise.race = race;
- Promise.resolve = resolve;
- Promise.reject = reject;
- Promise._setScheduler = setScheduler;
- Promise._setAsap = setAsap;
- Promise._asap = asap;
- Promise.prototype = {
- constructor: Promise,
- /**
- The primary way of interacting with a promise is through its `then` method,
- which registers callbacks to receive either a promise's eventual value or the
- reason why the promise cannot be fulfilled.
-
- ```js
- findUser().then(function(user){
- // user is available
- }, function(reason){
- // user is unavailable, and you are given the reason why
- });
- ```
-
- Chaining
- --------
-
- The return value of `then` is itself a promise. This second, 'downstream'
- promise is resolved with the return value of the first promise's fulfillment
- or rejection handler, or rejected if the handler throws an exception.
-
- ```js
- findUser().then(function (user) {
- return user.name;
- }, function (reason) {
- return 'default name';
- }).then(function (userName) {
- // If `findUser` fulfilled, `userName` will be the user's name, otherwise it
- // will be `'default name'`
- });
-
- findUser().then(function (user) {
- throw new Error('Found user, but still unhappy');
- }, function (reason) {
- throw new Error('`findUser` rejected and we're unhappy');
- }).then(function (value) {
- // never reached
- }, function (reason) {
- // if `findUser` fulfilled, `reason` will be 'Found user, but still unhappy'.
- // If `findUser` rejected, `reason` will be '`findUser` rejected and we're unhappy'.
- });
- ```
- If the downstream promise does not specify a rejection handler, rejection reasons will be propagated further downstream.
-
- ```js
- findUser().then(function (user) {
- throw new PedagogicalException('Upstream error');
- }).then(function (value) {
- // never reached
- }).then(function (value) {
- // never reached
- }, function (reason) {
- // The `PedgagocialException` is propagated all the way down to here
- });
- ```
-
- Assimilation
- ------------
-
- Sometimes the value you want to propagate to a downstream promise can only be
- retrieved asynchronously. This can be achieved by returning a promise in the
- fulfillment or rejection handler. The downstream promise will then be pending
- until the returned promise is settled. This is called *assimilation*.
-
- ```js
- findUser().then(function (user) {
- return findCommentsByAuthor(user);
- }).then(function (comments) {
- // The user's comments are now available
- });
- ```
-
- If the assimliated promise rejects, then the downstream promise will also reject.
-
- ```js
- findUser().then(function (user) {
- return findCommentsByAuthor(user);
- }).then(function (comments) {
- // If `findCommentsByAuthor` fulfills, we'll have the value here
- }, function (reason) {
- // If `findCommentsByAuthor` rejects, we'll have the reason here
- });
- ```
-
- Simple Example
- --------------
-
- Synchronous Example
-
- ```javascript
- let result;
-
- try {
- result = findResult();
- // success
- } catch(reason) {
- // failure
- }
- ```
-
- Errback Example
-
- ```js
- findResult(function(result, err){
- if (err) {
- // failure
- } else {
- // success
- }
- });
- ```
-
- Promise Example;
-
- ```javascript
- findResult().then(function(result){
- // success
- }, function(reason){
- // failure
- });
- ```
-
- Advanced Example
- --------------
-
- Synchronous Example
-
- ```javascript
- let author, books;
-
- try {
- author = findAuthor();
- books = findBooksByAuthor(author);
- // success
- } catch(reason) {
- // failure
- }
- ```
-
- Errback Example
-
- ```js
-
- function foundBooks(books) {
-
- }
-
- function failure(reason) {
-
- }
-
- findAuthor(function(author, err){
- if (err) {
- failure(err);
- // failure
- } else {
- try {
- findBoooksByAuthor(author, function(books, err) {
- if (err) {
- failure(err);
- } else {
- try {
- foundBooks(books);
- } catch(reason) {
- failure(reason);
- }
- }
- });
- } catch(error) {
- failure(err);
- }
- // success
- }
- });
- ```
-
- Promise Example;
-
- ```javascript
- findAuthor().
- then(findBooksByAuthor).
- then(function(books){
- // found books
- }).catch(function(reason){
- // something went wrong
- });
- ```
-
- @method then
- @param {Function} onFulfilled
- @param {Function} onRejected
- Useful for tooling.
- @return {Promise}
- */
- then: then,
- /**
- `catch` is simply sugar for `then(undefined, onRejection)` which makes it the same
- as the catch block of a try/catch statement.
-
- ```js
- function findAuthor(){
- throw new Error('couldn't find that author');
- }
-
- // synchronous
- try {
- findAuthor();
- } catch(reason) {
- // something went wrong
- }
-
- // async with promises
- findAuthor().catch(function(reason){
- // something went wrong
- });
- ```
-
- @method catch
- @param {Function} onRejection
- Useful for tooling.
- @return {Promise}
- */
- 'catch': function _catch(onRejection) {
- return this.then(null, onRejection);
- }
- };
- function polyfill() {
- var local = undefined;
- if (typeof global !== 'undefined') {
- local = global;
- } else if (typeof self !== 'undefined') {
- local = self;
- } else {
- try {
- local = Function('return this')();
- } catch (e) {
- throw new Error('polyfill failed because global object is unavailable in this environment');
- }
- }
- var P = local.Promise;
- if (P) {
- var promiseToString = null;
- try {
- promiseToString = Object.prototype.toString.call(P.resolve());
- } catch (e) {
- // silently ignored
- }
- if (promiseToString === '[object Promise]' && !P.cast) {
- return;
- }
- }
- local.Promise = Promise;
- }
- polyfill();
- // Strange compat..
- Promise.polyfill = polyfill;
- Promise.Promise = Promise;
- return Promise;
- })));
- //# sourceMappingURL=es6-promise.map
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