Backbone.Transceiver

This is a Backbone plugin that simplifies the use of Backbone.Radio in Marionette applications. It allows to declaratively configure events, requests, and commands using a simple syntax:

var MyApplication = Marionette.Application.extend({

    channels: {
        // configure app channel
        app: {
            reply: {
                'users': 'users'
                'users:current': 'getCurrentUser'
            },
            comply: {
                'show:modal': 'showModal'
            },
            events: {
                'change:lang': 'onLanguageChanged'
            },
            request: {
                'language': 'lang'
            }
        }
    },
    
    initialize: function() {
        // initialize
        this.users = new Users();
    },
    
    getCurrentUser: function() {
        return this.users.getCurrent();
    },
    
    showModal: function() {
        // show modal view using language requested from app channel
        var view = new ModalView(this.lang);
    },
    
    onLanguageChanged: function(language) {
        // handle changed language
    }

});

Convenience access to channels

For each channel name that is used in the channels configuration object, a convenience property is added:

var MyApplication = Marionette.Application.extend({

    channels: {
        app: {
            // ...
        },
        other: {}
    },
    
    notifyOthers: function() {
        this.channels.appChannel.trigger('change:something');
    }

});

If you only want access to a channel without configuring anything else, simply use an empty object as value.

Replying to requests

With reply, you can easily reply to requests from other objects in your application. The key corresponds to the request's name and the value is always a string corresponding to a property or function of the context object.

var MyApplication = Marionette.Application.extend({

    channels: {
        // configure app channel
        app: {
            reply: {
                'users': 'users'
                'users:current': 'getCurrentUser'
            },
            // ...
        }
    },
    
    initialize: function() {
        // initialize
        this.users = new Users();
    },
    
    getCurrentUser: function() {
        return this.users.getCurrent();
    },
    
    // ...

});

Complying to commands

With comply, you can easily implement commands, which works basically the same as with replies, though only method names are allowed as values.

Listening to events

events allows you to handle any event that is triggered on a channel. Simply use the event handlers name as value.

var MyApplication = Marionette.Application.extend({

    channels: {
        // configure app channel
        app: {
            // ...
            events: {
                'change:lang': 'onLanguageChanged'
            },
            // ...
        }
    },
    
    // ...
    
    onLanguageChanged: function(language) {
        // handle changed language
    }

});

Requesting data

In addition to replying to requests from other entities, you can, of course, also easily request data. When requesting data for a certain key, a EcmaScript 5.1 getter is added to the context object, which will dynamically request the data when the corresponding property is accessed:

var MyApplication = Marionette.Application.extend({

    channels: {
        // configure app channel
        app: {
            //...
            request: {
                'language': 'lang'
            }
        }
    },
    
    // ...
    
    showModal: function() {
        // accessing this.lang will dynamically request 'language' from the channel
        var view = new ModalView(this.lang);
    }
    
    // ...
    
});

Limitations

Currently, it is not possible to use any of the dynamically configured features in initialize functions, as there is no easy way to hook into construction of a Backbone/Marionette object before initialize is called (see http://ianstormtaylor.com/backbonejs-configuration-logic-should-be-extendable/ for a description of the problem).