backbone-command

Execution of commands upon event triggers. This is build for usage with Backbone and relies on injector.js

Install

You could just download backbone-command.js or backbone-command.min.js from the project root.

We advise you to download it using Bower instead:

bower install backbone-command

This command will automatically download all dependencies. So in this case it takes care of downloading injector.js, jQuery, Backbone and Underscore for you.

Theory

Essentially a command is just a class with one method function. This method gets executed and then the command instance stops to exist. As the command is a single class and can live in a separate file, it can be nicely separated from the rest of your application. It helps keeping your classes decoupled by separating the action from the rest of the system. Say you have a search view. Once the user enters a new search query we should execute a search. The view should not know about how such logic is handled, all it knows is that it has to set the search query on a model. A command can then take care of executing the desired logic. This might mean a backend call and changing the loading property to true on a model for example. Commands are essentially the glue of your application. Your models and views should be completely agnostic, but the command can bring all of these together. A command has access to the injector and therefor usually has access to everything it needs.

Usage

A typical command looks as follows:

var YourCommand = Backbone.Command.extend({
	someModel: 'inject',

	execute: function() {
		//Your logic...
	}
});

In the current setup the router is (ab)used as the central place that connects events to the execution of commands, but also takes care registering injector rules. An injector is automatically instantiated for you when you extend the Backbone.CommandRouter

A very basic extended CommandRouter would look like this:

var ApplicationRouter = Backbone.CommandRouter.extend({
	initialize: function() {
		var someModel = new Backbone.Model();
		this.injector.map('someModel').toValue(someModel);

		this.bindCommand(someModel, "change:someProperty", YourCommand);
	}
});

In this example we register someModel to the injector and map a change of someProperty to the execution of YourCommand

Example implementation

Please refer to Navigator-Injector-Backbone-Command-TodoMVC example for details of how this library can be used.

Support

Feel free to create a new issue for all your questions, issues or feature requests.