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The Backbone.Marionette.Application object is the hub of your composite application. It organizes, initializes and coordinates the various pieces of your app. It also provides a starting point for you to call into from your HTML script block, or directly from your JavaScript files if you prefer to go that route.

The Application is meant to be instantiated directly, although you can extend it to add your own functionality.

var MyApp = new Backbone.Marionette.Application();

Documentation Index


Initialize is called immediately after the Application has been instantiated, and is invoked with the same arguments that the constructor received.

var MyApp = Marionette.Application.extend({
  initialize: function(options) {

var myApp = new MyApp({container: '#app'});

Application Events

The Application object raises a few events during its lifecycle, using the Marionette.triggerMethod function. These events can be used to do additional processing of your application. For example, you may want to pre-process some data just before initialization happens. Or you may want to wait until your entire application is initialized to start Backbone.history.

The events that are currently triggered, are:

MyApp.on("before:start", function(options){
  options.moreData = "Yo dawg, I heard you like options so I put some options in your options!"

MyApp.on("start", function(options){
  if (Backbone.history){

The options parameter is passed through the start method of the application object (see below).

Starting An Application

Once you have your application configured, you can kick everything off by calling: MyApp.start(options).

This function takes a single optional parameter. This parameter will be passed to each of your initializer functions, as well as the initialize events. This allows you to provide extra configuration for various parts of your app throughout the initialization sequence.

var options = {
  something: "some value",
  another: "#some-selector"


Application Regions

Warning: deprecated This feature is deprecated. Instead of using the Application as the root of your view tree, you should use a Layout View. To scope your Layout View to the entire document, you could set its el to 'body'. This might look something like the following:

var RootView = Marionette.LayoutView.extend({ el: 'body' });

Application instances have an API that allow you to manage Regions. These Regions are typically the means through which your views become attached to the document.

You can create Regions through the addRegions method by passing in an object literal or a function that returns an object literal.

There are three syntax forms for adding a region to an application object.

jQuery Selector

The first is to specify a jQuery selector as the value of the region definition. This will create an instance of a Marionette.Region directly, and assign it to the selector:

  someRegion: "#some-div",
  anotherRegion: "#another-div"

Custom Region Class

The second is to specify a custom region class, where the region class has already specified a selector:

var MyCustomRegion = Marionette.Region.extend({
  el: "#foo"

MyApp.addRegions(function() {
  return {
    someRegion: MyCustomRegion

Custom Region Class And Selector

The third method is to specify a custom region class, and a jQuery selector for this region instance, using an object literal:

var MyCustomRegion = Marionette.Region.extend({});


  someRegion: {
    selector: "#foo",
    regionClass: MyCustomRegion

  anotherRegion: {
    selector: "#bar",
    regionClass: MyCustomRegion


Region Options

You can also specify regions per Application instance.

new Marionette.Application({
  regions: {
    fooRegion: '#foo-region'

Overriding the default RegionManager

If you need the RegionManager's class chosen dynamically, specify getRegionManager:

  // ...

  getRegionManager: function() {
    // custom logic
    return new MyRegionManager();

This can be useful if you want to attach Application's regions to your own instance of RegionManager.

Get Region By Name

A region can be retrieved by name, using the getRegion method:

var app = new Marionette.Application();
app.addRegions({ r1: "#region1" });

var myRegion = app.getRegion('r1');

Regions are also attached directly to the Application instance, but this is not recommended usage.

Removing Regions

Regions can also be removed with the removeRegion method, passing in the name of the region to remove as a string value:


Removing a region will properly empty it before removing it from the application object.

For more information on regions, see the region documentation Also, the API that Applications use to manage regions comes from the RegionManager Class, which is documented over here.


Retrieve an object's attribute either directly from the object, or from the object's this.options, with this.options taking precedence.

More information getOption

Adding Initializers

Warning: deprecated

This feature is deprecated, and is scheduled to be removed in version 3 of Marionette. Instead of Initializers, you should use events to manage start-up logic. The start event is an ideal substitute for Initializers.

If you were relying on the deferred nature of Initializers in your app, you should instead use Promises. This might look something like the following:


Your application needs to do useful things, like displaying content in your regions, starting up your routers, and more. To accomplish these tasks and ensure that your Application is fully configured, you can add initializer callbacks to the application.

  // do useful stuff here
  var myView = new MyView({
    model: options.someModel

  new MyAppRouter();

These callbacks will be executed when you start your application, and are bound to the application object as the context for the callback. In other words, this is the MyApp object inside of the initializer function.

The options argument is passed from the start method (see below).

Initializer callbacks are guaranteed to run, no matter when you add them to the app object. If you add them before the app is started, they will run when the start method is called. If you add them after the app is started, they will run immediately.

The Application Channel

Warning: deprecated

This feature is deprecated, and is scheduled to be removed in the next major release of Marionette. Instead of accessing Channels through the Application, you should use the Wreqr (or Radio) API. By default the application's channel is named 'global'. To access this channel, you can use the following code, depending on whether you're using Wreqr or Radio:

// Wreqr
var globalCh = Backbone.Wreqr.radio.channel('global');

// Radio
var globalCh = Backbone.Radio.channel('global');

Marionette Applications come with a messaging system to facilitate communications within your app.

The messaging system on the Application is the radio channel from Backbone.Wreqr, which is actually comprised of three distinct systems.

Marionette Applications default to the 'global' channel, but the channel can be configured.

var MyApp = new Marionette.Application({ channelName: 'appChannel' });

This section will give a brief overview of the systems; for a more in-depth look you are encouraged to read the Backbone.Wreqr documentation.

Event Aggregator

The Event Aggregator is available through the vent property. vent is convenient for passively sharing information between pieces of your application as events occur.

var MyApp = new Backbone.Marionette.Application();

// Alert the user on the 'minutePassed' event
MyApp.vent.on("minutePassed", function(someData){
  alert("Received", someData);

// This will emit an event with the value of window.someData every minute
window.setInterval(function() {
  MyApp.vent.trigger("minutePassed", window.someData);
}, 1000 * 60);

Request Response

Request Response is a means for any component to request information from another component without being tightly coupled. An instance of Request Response is available on the Application as the reqres property.

var MyApp = new Backbone.Marionette.Application();

// Set up a handler to return a todoList based on type
MyApp.reqres.setHandler("todoList", function(type){
  return this.todoLists[type];

// Make the request to get the grocery list
var groceryList = MyApp.reqres.request("todoList", "groceries");

// The request method can also be accessed directly from the application object
var groceryList = MyApp.request("todoList", "groceries");


Commands are used to make any component tell another component to perform an action without a direct reference to it. A Commands instance is available under the commands property of the Application.

Note that the callback of a command is not meant to return a value.

var MyApp = new Backbone.Marionette.Application();

MyApp.model = new Backbone.Model();

// Set up the handler to call fetch on the model
MyApp.commands.setHandler("fetchData", function(reset){
  MyApp.model.fetch({reset: reset});

// Order that the data be fetched
MyApp.commands.execute("fetchData", true);

// The execute function is also available directly from the application
MyApp.execute("fetchData", true);

Accessing the Application Channel

To access this application channel from other objects within your app you are encouraged to get a handle of the systems through the Wreqr API instead of the Application instance itself.

// Assuming that we're in some class within your app,
// and that we are using the default 'global' channel
// it is preferable to access the channel like this:
var globalCh = Backbone.Wreqr.radio.channel('global');

// This is discouraged because it assumes the name of your application
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