Promiser

promiser is a simple manager of deferreds by name. Rather than creating and maintaining references to jQuery.Deferred objects, simply register a handler by name and resolve or reject it by name.

promiser.done('test', function() {
    console.log('hello world');
});

promiser.resolve('test');

promiser.isResolved('test'); // true

The promiser API includes all the methods on the jQuery Deferred object.

Chaining works as expected:

promiser
    .done('test1', function() { ... })
    .done('test2', function() { ... })
    .done('test3', function() { ... });

For a more elegant approach, an object can be passed:

promiser.done({
    test1: function() { ... },
    test2: function() { ... },
    test3: function() { ... }
});

It supports the when method:

promiser.when('test1', 'test2', 'test3', function() {
    console.log('all done!');
});

Promiser can manage other deferred for you:

promiser.manage('ajax', $.ajax({ ... }));

It can also stop managing a deferred:

var xhr = promiser.unmanage('ajax');

You can even reset a deferred. This provides a clean alternative to passing around references to deferred objects:

promiser.reset('test1');

Deferreds can be watched for when they are initially created. This makes it easy to only execute something if another object needs it:

// Watch for the first time the 'lazy-data' deferrred it bound to
promiser.watch('lazy-data', function() {
    $.ajax({
        success: function(data) {
            promiser.resolve('lazy-data', data);
        },
        error: function(xhr, text, err) {
            promiser.reject('lazy-data', xhr, text, err);
        }
    });
});

// This executes the watch handler above
promiser.done('lazy-data', function(data) {
    // do something...
});

Install

bower install promiser

Setup

promiser.js works in the browser as well as the Node and AMD environments.

Usage

The promiser object can be used three ways:

As Is

// It itself implements the promiser API
promiser.done('foo', function() { ... });

Constructor

// Create promiser objects
var p1 = new promiser;
p1 instanceof promiser; // true

Function

// Create a new plain object
var p1 = promiser();

// Extend an existing object
var p2 = promiser({});