Toposort


__Sorting directed acyclic graphs, for Node.js, io.js and the browser__
_This was originally done by Marcel Klehr. Why not checkout his original repo?_

Installation

There are a few ways for installing Toposort. Here are them:

* Via NPM: npm install toposort-class
* Via Bower: bower install toposort
* Via Git: git clone git://github.com/gustavohenke/toposort.git
* Direct download (Minified) for use in the browser

Example

Let's say you have the following dependency graph:

* Plugin depends on Backbone and jQuery UI Button;
* Backbone depends on jQuery and Underscore;
* jQuery UI Button depends on jQuery UI Core and jQuery UI Widget;
* jQuery UI Widget and jQuery UI Core depend on jQuery;
* jQuery and Underscore don't depend on anyone.

Now, how would you sort this in a way that each asset will be correctly placed? You'll probably need the following sorting:

* jQuery, jQuery UI Core, jQuery UI Widget, jQuery UI Button, Underscore, Backbone, Plugin

You can achieve it with the following code, using toposort-class:
``javascript
var Toposort = require('toposort-class'),
t = new Toposort();

t.add("jquery-ui-core", "jquery")
.add("jquery-ui-widget", "jquery")
.add("jquery-ui-button", ["jquery-ui-core", "jquery-ui-widget"])
.add("plugin", ["backbone", "jquery-ui-button"])
.add("backbone", ["underscore", "jquery"]);

console.log(t.sort().reverse());

/* Will output:
* ['jquery', 'jquery-ui-core', 'jquery-ui-widget', 'jquery-ui-button', 'underscore', 'backbone', 'plugin']
*
* And you're done.
*/
`

Usage


CommonJS (Node.js and io.js):
`javascript
var Toposort = require('toposort-class'),
t = new Toposort();
`

Browser with AMD:
`javascript
define("myModule", ["Toposort"], function(Toposort) {
var t = new Toposort();
});
`

Browser without AMD:
`javascript
var t = new window.Toposort();
`

or whatever global object there is instead of window.

API

#### .add(item, deps)
* _{String}_ item - The name of the dependent item that is being added
* _{Array|String}_ deps - A dependency or list of dependencies of item

__Returns:__ _{Toposort}_ The Toposort instance, for chaining.

#### .sort()
__Returns:__ _{Array}_ The list of dependencies topologically sorted.

This method will check for cyclic dependencies, like "A is dependent of A".

#### .clear()
__Returns:__ _{Toposort}_ The Toposort instance, for chaining.

Clears all edges, effectively resetting the instance.

#### .Toposort`

Reference to the Toposort constructor.

Legal

MIT License