AddRegions is not a function

Question

Simple code for start App

   define(['marionette'],function (Marionette) {


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

        MyApp.addInitializer(function(options) {

        })
        MyApp.addRegions({
            mainRegion: "#content"
        });
    })

// MarionetteJS (Backbone.Marionette)
// ----------------------------------
// v3.1.0
//     Backbone.js 1.3.3

How to fix ?

Answer 1

As of Marionette version 3 addRegions is no longer supported. Instead, you can specify your root region as below:

var App = Backbone.Marionette.Application.extend({
  region: '#content',
  initialize: function() {
    // init
  },
  onStart: function() {
    // start application
  }
});

var myApp = new App();
myApp.start();

You can check out the Marionette v3 documentation for more.