AlloyUI - API Docs

  • API Docs for Version: 3.1.0-deprecated.60

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    Promise Class

    Defined in: yui3/src/promise/js/promise.js:30
    Module: promise

    A promise represents a value that may not yet be available. Promises allow you to chain asynchronous operations, write synchronous looking code and handle errors throughout the process.

    This constructor takes a function as a parameter where you can insert the logic that fulfills or rejects this promise. The fulfillment value and the rejection reason can be any JavaScript value. It's encouraged that rejection reasons be error objects

    <pre><code> var fulfilled = new Y.Promise(function (resolve) { resolve('I am a fulfilled promise'); });

    var rejected = new Y.Promise(function (resolve, reject) { reject(new Error('I am a rejected promise')); }); </code></pre>

    Constructor

    Promise

    (
    • fn
    )

    Defined in yui3/src/promise/js/promise.js:30

    Parameters:

    • fn Function

      A function where to insert the logic that resolves this promise. Receives resolve and reject functions as parameters. This function is called synchronously.

    Index

    Methods

    Properties

    Methods

    _wrap

    (
    • resolve
    • reject
    • fn
    )
    Function private

    Defined in yui3/src/promise/js/promise.js:155

    Wraps the callback in another function to catch exceptions and turn them into rejections.

    Parameters:

    • resolve Function

      Resolving function of the resolver that handles this promise

    • reject Function

      Rejection function of the resolver that handles this promise

    • fn Function

      Callback to wrap

    Returns:

    Function:

    all

    (
    • values
    )
    static

    Defined in yui3/src/promise/js/promise.js:255

    Returns a promise that is resolved or rejected when all values are resolved or any is rejected. This is useful for waiting for the resolution of multiple promises, such as reading multiple files in Node.js or making multiple XHR requests in the browser.

    Parameters:

    • values Any

      An array of any kind of values, promises or not. If a value is not

    Returns:

    [Promise] A promise for an array of all the fulfillment values

    catch

    (
    • [Function]
    )
    Promise

    Defined in yui3/src/promise/js/promise.js:124

    A shorthand for promise.then(undefined, callback).

    Returns a new promise and the error callback gets the same treatment as in then: errors get caught and turned into rejections, and the return value of the callback becomes the fulfilled value of the returned promise.

    Parameters:

    • [Function] Object optional

      errback Callback to be called in case this promise is rejected

    Returns:

    Promise:

    A new promise modified by the behavior of the error callback

    getStatus

    () String deprecated

    Defined in yui3/src/promise/js/promise.js:141

    Returns the current status of the operation. Possible results are "pending", "fulfilled", and "rejected".

    Returns:

    String:

    isPromise

    (
    • obj
    )
    Boolean static

    Defined in yui3/src/promise/js/promise.js:191

    Checks if an object or value is a promise. This is cross-implementation compatible, so promises returned from other libraries or native components that are compatible with the Promises A+ spec should be recognized by this method.

    Parameters:

    • obj Any

      The object to test

    Returns:

    Boolean:

    Whether the object is a promise or not

    race

    (
    • values
    )
    Promise static

    Defined in yui3/src/promise/js/promise.js:301

    Returns a promise that is resolved or rejected when any of values is either resolved or rejected. Can be used for providing early feedback in the UI while other operations are still pending.

    Parameters:

    • values Any

      An array of values or promises

    Returns:

    Promise:

    reject

    (
    • reason
    )
    Promise static

    Defined in yui3/src/promise/js/promise.js:238

    A shorthand for creating a rejected promise.

    Parameters:

    • reason Any

      Reason for the rejection of this promise. Usually an Error Object

    Returns:

    Promise:

    A rejected promise

    resolve

    (
    • Any
    )
    Promise static

    Defined in yui3/src/promise/js/promise.js:215

    Ensures that a certain value is a promise. If it is not a promise, it wraps it in one.

    This method can be copied or inherited in subclasses. In that case it will check that the value passed to it is an instance of the correct class. This means that PromiseSubclass.resolve() will always return instances of PromiseSubclass.

    Parameters:

    • Any Any

      object that may or may not be a promise

    Returns:

    Promise:

    then

    (
    • [callback]
    • [errback]
    )
    Promise

    Defined in yui3/src/promise/js/promise.js:85

    Schedule execution of a callback to either or both of "fulfill" and "reject" resolutions for this promise. The callbacks are wrapped in a new promise and that promise is returned. This allows operation chaining ala functionA().then(functionB).then(functionC) where functionA returns a promise, and functionB and functionC may return promises.

    Asynchronicity of the callbacks is guaranteed.

    Parameters:

    • [callback] Function optional

      function to execute if the promise resolves successfully

    • [errback] Function optional

      function to execute if the promise resolves unsuccessfully

    Returns:

    Promise:

    A promise wrapping the resolution of either "resolve" or "reject" callback

    Properties

    _resolver

    Object private

    Defined in yui3/src/promise/js/promise.js:64

    A reference to the resolver object that handles this promise