machina.Promise

A lightweight Promises/A compliant implementation for projects already using the machina state machine library. It does not currently implement progress callbacks.

Examples

Basic Example

var promise = new machina.Promise();

promise.then( function ( num ) {
	return num + 5
}).then( function ( num ) {
	console.log( "New number", num ); // Expected output is 7
});

promise.fulfill( 7 );

Basic Example with an Error Handler

var promise = new machina.Promise();

promise.then( null, function ( reason ) {
	console.log( "Error", reason );

	// Use 0 when the promise fails
	return 0;
})
.then( function ( num ) {
	return num + 5
})
.then( function ( num ) {
	console.log( "New number", num ); // Expected output is 5
});

promise.reject( "AJAX call");

API

machina.Promise - Constructor

Usage: var promise = new machina.Promise()

machina.Promise.useExtensions - Boolean - Configuration property

To use strict Promises/A, set this property to false. The differences are as follows:

Callbacks returning promises

• In useExtensions = true mode, if a then callback returns a promise, the promise returned from the then method itself won't be fulfilled or rejected until the callbacks promise was fulfilled or rejected.
• In useExtensions = false mode, the result from the callback, even if its a promise, will be passed to the next callback as the value.

Always Asynchronous

• In useExtensions = true mode, callbacks in then are always executed asynchronously, even if the promise is already fulfilled or rejected when the callbacks are attached.
• In useExtensions = false mode, callbacks will be asynchronous until the promise is fulfilled or rejected. Subsequent callbacks attached to the promise will be executed synchronously

Instance Methods

In addition to the normal machina FSM API, the following methods are exposed:

• reject( reason ) - Move a promise into a failed state. The first parameter passed to this method is used as the reason.
• fulfill( value ) - Move a promise into a fulfilled state. The first parameter passed to this method is used as the value of the fulfilled promise.
• then( fulfilledCallback, rejectedCallback ) - Returns a new Promise - Attach callbacks to be notified when a promise is rejected or fulfilled (or both). The new promise returned by this method will be resolved with return value from either the fulfilled or rejected callback, or rejected if either of the callbacks throw an error. For finer control over this, you can return your own promise from either callback, and that new promise will control the fulfilled or rejected state of the existing promise returned by this method.

Tests

There are a few tests in the spec folder, but there is a test adapter for the incredible domenic/promise-tests.

Download or fork and clone the repo to your computer, then (first time only):

cd machina.promise
npm install

Then to run the tests:

npm test

Development

This repository uses the Anvil build system. It is not included as dependency as anvil is normally installed globally. To install anvil:

npm install -g anvil

To run the build (Takes the files from src and builds them into lib):

anvil

To run the build continually after each change:

anvil --ci

License

This project is available under a dual license of MIT or GPL v2.0

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Copyright (c) 2012 appendTo (MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

See the MIT License for more details: http://opensource.org/licenses/MIT

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Copyright (C) 2012 appendTo (GPL v2.0 License)

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details: http://opensource.org/licenses/GPL-2.0