API Docs for: 0.1.4
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$q Class

Defined in: src/builtins/Promise.js:209
Module: Builtins

Creates and manages promises. Used by $http and $routing.

$q is used to create a deferred object, which contains a promise. The deferred is used to create and manage promises.

A promise accepts resolution, rejection and notification handlers that are executed when the promise itself is resolved, rejected or notified. The handlers are attached to the promise via the .then() method.

You can attach multiple handlers by calling .then() multiple times with different handlers. In addition, you can chain .then() calls. In this case, the return value from .then() is a new promise that's attached to the resolve handler passed to .then(). This way you can return promises from your resolve handler and the next .then() will wait until that promise is resolved to continue. Usually used to do multiple asyncronous calls in sequence.

Constructor

$q

(
  • callback
)
Promise

Defined in src/builtins/Promise.js:209

Parameters:

  • callback Function

    The callback to initialized the deferred object with

Returns:

Promise:

Item Index

Methods

Methods

all

(
  • promises
)
Promise

Defined in src/builtins/Promise.js:298

Takes an array of promises (called inner promises) and creates a new promise (called outer promise) that resolves when all the inner promises resolve. If any of the inner promises are rejected, the outer promise is immediately rejected as well and any other inner promises left over are discarded.

E.g. if you have three inner promises, A, B, and C, then the outer promise O is resolved once all three A, B and C are resolved.

If A is resolved, and B is rejected, and C is pending, then O will be rejected regardless of C's outcome.

Parameters:

  • promises Array

    Array of promises

Returns:

Promise:

Example:

 let greeting = $q.defer();
 let name = $q.defer();

 $q.all([greeting.promise, name.promise])
     .then((greeting, name) => console.log(greeting + ' ' + name));

 greeting.resolve('Welcome');
 name.resolve('John')
 //=> "Welcome John"

defer

() Deferred

Defined in src/builtins/Promise.js:237

Create a new defer. This method requires no arguments, the returned defer has the methods required to resolve/reject/notify the promise.

Returns:

Deferred:

Example:

 let defer = $q.defer();
 defer.promise.then((name) => console.log('Hi ' + name));
 defer.resolve('John');
 //=> "Hi John"

resolve

()

Defined in src/builtins/Promise.js:291

Alias for $q.when

when

(
  • value
  • [onResolve]
  • [onReject]
  • [onNotify]
)
Promise

Defined in src/builtins/Promise.js:254

Creates a new promise and resolves it with value. If value is a promise, the returned promise is attached to value. If onResolve, onReject or onNotify are given, they are attached to the new promise.

Parameters:

  • value | Promise

    Value that the returned promise is resolve with. If value is a promise, the returned promise is attached to value.

  • [onResolve] Function optional

    Resolve handler

  • [onReject] Function optional

    Rejection handler

  • [onNotify] Function optional

    Notification handler

Returns:

Promise:

Example:

 $q.when('John').then((name) => console.log('Hi ' + name));
 //=> "Hi John"