Topological sort of directed acyclic graphs (like dependecy lists)


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?

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://
  • Direct download (Minified) for use in the browser

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

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.

  • {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.

Returns: {Array} The list of dependencies topologically sorted.

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

Returns: {Toposort} The Toposort instance, for chaining.

Clears all edges, effectively resetting the instance.

Reference to the Toposort constructor.

MIT License