Thenable

Embeddable Minimum Strictly-Compliant Promises/A+ 1.1.1 Thenable
Copyright (c) 2013-2014 Ralf S. Engelschall (http://engelschall.com)
Licensed under The MIT License (http://opensource.org/licenses/MIT)

Abstract

This is a strictly-compliant Promises/A+ 1.1.1 implementation in just 2KB of (compressed) code, which passes the official Promises/A+ Test-Suite and includes back-references to the relevant specification statements. It just provides a minimum Promise functionality, because it is intended to be directly embedded into ECMAScript 5 based libraries and frameworks, in order to dependency-free leverage from Promises and be able to return "thenable" Promise objects to applications. As such, it only provides the bare Promise creation and resolving functionalities and no general Promise management functionalities. For applications (and similar contexts where extra dependencies do not matter), please use a full-featured Promise library like Bluebird or any of the other Promise/A+ compliant implementations instead.

Usage

Although (thanks to UMD) also usable in a stand-alone fashion in AMD, CommonJS and Browser environments, Thenable is primarily intended for embedding into dependency-free libraries and frameworks. Hence, it intentionally is neither published to the Node NPM registry nor to the Bower registry. Instead, please download the raw thenable.min.js and include it verbatim into your library/framework. The usual approach for this is to temporarily emulate a CommonJS environment within your library/framework to get its Thenable object:

var Thenable = (function () {
    var module = { exports: {} };
    /* --- START VERBATIM EMBEDDING ---- */
/*!
**  Thenable -- Embeddable Minimum Strictly-Compliant Promises/A+ 1.1.1 Thenable
**  Copyright (c) 2013-2014 Ralf S. Engelschall <http://engelschall.com>
**  Licensed under The MIT License <http://opensource.org/licenses/MIT>
**  Source-Code distributed on <http://github.com/rse/thenable>
*/
!function[...]
    /* --- END VERBATIM EMBEDDING ---- */
    return module.exports;
})();

Then to use Thenable you can do either...

myAsyncMethod = function () {
    var promise = new Thenable();
    doAsyncOperation(function onResult (result) {
        promise.fulfill(result);
    }, function onError (error) {
        promise.reject(result);
    })
    return promise.proxy();
};

...or the EMCAScript 6 style...

myAsyncMethod = function () {
    return new Thenable(function (fulfill, reject) {
        doAsyncOperation(function onResult (result) {
            fulfill(result);
        }, function onError (error) {
            reject(result);
        })
    }).proxy();
};

Features

• strictly-compliant to Promises/A+ 1.1.1
• source-code includes back-references to the relevant specification statements
• bare Promise creation and resolving functionality
• Universal Module Definition (UMD) for AMD, CommonJS and Browser support
• optional noConflict method for non-invasive use in Browser environments
• Static Constructor Function support
• additional Promise Proxy support
• additional Constructor Executor support
• permissive MIT license
• just 2KB of (compressed) code