--- /dev/null
+import {
+ isFunction
+} from './utils';
+
+import {
+ noop,
+ nextId,
+ PROMISE_ID,
+ initializePromise
+} from './-internal';
+
+import {
+ asap,
+ setAsap,
+ setScheduler
+} from './asap';
+
+import all from './promise/all';
+import race from './promise/race';
+import Resolve from './promise/resolve';
+import Reject from './promise/reject';
+import then from './then';
+
+
+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
+*/
+export default 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(onRejection) {
+ return this.then(null, onRejection);
+ }
+};
projects / yaffs-website / blobdiff