Creating an Application

The most important object in T3 is Box.Application. This object is responsible for managing all components on the page: modules, services, and behaviors. It keeps track of the components as well as managing their lifecycle.


Any page you want to use T3 on needs to initialize the application using the init() method. For example:


Exactly where and when you call init() depends on when you want to start the application lifecycle. Some of the places where it’s appropriate to call init() include:

The only prerequisite to calling init() is that you have already loaded the T3 components that are required for the page.

Global Configuration

It’s possible your application may need to share some configuration with its components. To do so, you can pass an object to init() specifying the additional information that should be available. For example:

    apiKey: 'abcxyz123'

In this case, the property apiKey will be available to all T3 components.

Debug Mode

Although configuration information is mostly inert, there is one special configuration option that causes a change in how T3 behaves. The debug property is used to indicate that the application is in debug mode.

    debug: true

Debug mode means that all errors are thrown and, as such, will show up in the browser console. When debug mode is off (by default), errors instead cause the error event to be emitted. You can then listen for errors with an event handler, such as:

Box.Application.on('error', function(event) {

    var exception = event.exception;

    // do something with the exception

This capability is provided so that it’s possible to detect errors in T3 components and take appropriate action. In production, for example, you may want to log these errors to the server. T3 is capable of catching most thrown errors in T3 components automatically, so you don’t need to use try-catch statements to keep the application from crashing due to a thrown error.

We recommended that you set debug to true when in development to make it easier to debug errors as they occur and set debug to false for production environments.