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:

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):

var Toposort = require('toposort-class'),
	t = new Toposort();

Browser with AMD:

define("myModule", ["Toposort"], function(Toposort) {
    var t = new Toposort();
});

Browser without AMD:

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