Marionette functions

Marionette provides a set of utility / helper functions that are used to facilitate common behaviors throughout the framework. These functions may be useful to those that are building on top of Marionette, as they provide a way to get the same behaviors and conventions from your own code.

Marionette.extend

Backbone's extend function is a useful utility to have, and is used in various places in Marionette. To make the use of this method more consistent, Backbone's extend has been aliased to Marionette.extend. This allows you to get the extend functionality for your object without having to decide if you want to use Backbone.View or Backbone.Model or another Backbone object to grab the method from.

var Mn = require('backbone.marionette');

var Foo = function(){};

// use Marionette.extend to make Foo extendable, just like other
// Backbone and Marionette objects
Foo.extend = Mn.extend;

// Now Foo can be extended to create a new class, with methods
var Bar = Foo.extend({

  someMethod: function(){ ... }

  // ...
});

// Create an instance of Bar
var b = new Bar();

Live example

Marionette.isNodeAttached

Determines whether the passed-in node is a child of the document or not.

var Mn = require('backbone.marionette');

var div = document.createElement('div');
Mn.isNodeAttached(div);
// => false

$('body').append(div);
Mn.isNodeAttached(div);
// => true

Live example

Marionette.mergeOptions

A handy function to pluck certain options and attach them directly to an instance. Most Marionette Classes, such as the Views, come with this method.

var Mn = require('backbone.marionette');

var MyView = Mn.View.extend({
  myViewOptions: ['color', 'size', 'country'],

  initialize: function(options) {
    this.mergeOptions(options, this.myViewOptions);
  },

  onRender: function() {
    // The merged options will be attached directly to the prototype
    this.$el.addClass(this.color);
  }
});

Live example

Marionette.getOption

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

var Bb = require('backbone');
var Mn = require('backbone.marionette');

var Model = Bb.Model.extend({
  foo: 'bar',

  initialize: function(attributes, options){
    this.options = options;
    var foo = Mn.getOption(this, 'foo');
    console.log(foo);
  }
});

var model1 = new Model(); // => "bar"

var model2 = new Model({}, { foo: 'quux' }); // => "quux"

Live example

This is useful when building an object that can have configuration set in either the object definition or the object's constructor options.

Falsey values

The getOption function will return any falsey value from the options, other than undefined. If an object's options has an undefined value, it will attempt to read the value from the object directly.

For example:

var Bb = require('backbone');
var Mn = require('backbone.marionette');

var Model = Bb.Model.extend({
  foo: 'bar',

  initialize: function(){
    var foo = Mn.getOption(this, 'foo');
    console.log(foo);
  }
});

var model1 = new Model(); // => "bar"

var foo;
var model2 = new Model({}, { foo: foo }); // => "bar"

Live example

In this example, "bar" is returned both times because the second example has an undefined value for f.

Marionette.triggerMethod

Trigger an event and a corresponding method on the target object.

When an event is triggered, the first letter of each section of the event name is capitalized, and the word "on" is tagged on to the front of it. Examples:

triggerMethod("render") fires the "onRender" function
triggerMethod("before:destroy") fires the "onBeforeDestroy" function

All arguments that are passed to the triggerMethod call are passed along to both the event and the method, with the exception of the event name not being passed to the corresponding method.

triggerMethod("foo", bar) will call onFoo: function(bar){...})

Note that triggerMethod can be called on objects that do not have Backbone.Events mixed in to them. These objects will not have a trigger method, and no attempt to call .trigger() will be made. The on{Name} callback methods will still be called, though.

Marionette.triggerMethodOn

Invoke triggerMethod on a specific context.

This is useful when it's not clear that the object has triggerMethod defined. In the case of views, Marionette.AbstractView defines triggerMethod, but Backbone.View does not.

var Mn = require('backbone.marionette');

Mn.triggerMethodOn(ctx, "foo", bar);
// will invoke `onFoo: function(bar){...})`
// will trigger "foo" on ctx

Marionette.bindEvents

This method is used to bind a backbone "entity" (e.g. collection/model) to methods on a target object.

var Bb = require('backbone');
var Mn = require('backbone.marionette');

Bb.View.extend({

  modelEvents: {
    'change:foo': 'doSomething'
  },

  initialize: function(){
    Mn.bindEvents(this, this.model, this.modelEvents);
  },

  doSomething: function(){
    // the "change:foo" event was fired from the model
    // respond to it appropriately, here.
  }

});

Live example

The first parameter, target, must have the Backbone.Events module mixed in.

The second parameter is the entity (Backbone.Model, Backbone.Collection or any object that has Backbone.Events mixed in) to bind the events from.

The third parameter is a hash of { "event:name": "eventHandler" } configuration. Multiple handlers can be separated by a space. A function can be supplied instead of a string handler name.

Marionette.unbindEvents

This method can be used to unbind callbacks from entities' (e.g. collection/model) events. It's the opposite of bindEvents, described above. Consequently, the APIs are identical for each method.

// Just like the above example we bind our model events.
// This time, however, we unbind them on close.
var Bb = require('backbone');
var Mn = require('backbone.marionette');

Bb.View.extend({

  modelEvents: {
    'change:foo': 'doSomething'
  },

  initialize: function(){
    Mn.bindEvents(this, this.model, this.modelEvents);
  },

  doSomething: function(){
    // the "change:foo" event was fired from the model
    // respond to it appropriately, here.
  },

  onClose: function() {
    Mn.unbindEvents(this, this.model, this.modelEvents);
  }

});

Live example

Marionette.bindRequests

This method is used to bind a radio requests to methods on a target object.

var Mn = require('backbone.marionette');
var Radio = require('backbone.radio');

var MyView = Mn.View.extend({
  channelName: 'myChannelName',

  radioRequests: {
    'foo:bar': 'fooBar'
  },

  initialize: function() {
    var channel = Radio.channel(this.channelName);
    Mn.bindRequests(this, channel, this.radioRequests);
  },

  fooBar: function() {
      console.log('foo:bar event was called')
  }
 });

var myView = new MyView();
var channel = Radio.channel('myChannelName');
channel.request('foo:bar'); // Logs 'foo:bar event was called'

Live example

The first parameter, this, is a context of current entity.

The second parameter, channel, reference to a channel by name.

The third parameter is a hash either { "event:name": "eventHandler" } or { "event:name": "eventHandler", "event:otherName": "otherEventHandler", ...} of configuration.

Marionette.unbindRequests

This method is used to unbind a radio requests to methods on a target object.

var Mn = require('backbone.marionette');
var Radio = require('backbone.radio');

var MyView = Mn.View.extend({
  channelName: 'myChannelName',

  radioRequests: {
    'foo:bar': 'fooBar'
  },

  initialize: function() {
    var channel = Radio.channel(this.channelName);
    Mn.bindRadioRequests(this, channel, this.radioRequests);
  },

  onDestroy: function() {
    var channel = Radio.channel(this.channelName);
    Mn.unbindRequests(this, channel, this.radioRequests);
  }
 });

var myView = new MyView();
myView.destroy();

Live examples

The first parameter, this, is a context of current entity.

The second parameter, channel, reference to a channel by name.

The third parameter is a hash either { "event:name": "eventHandler" } or { "event:name": "eventHandler", "event:otherName": "otherEventHandler", ...} of configuration.

Marionette.normalizeMethods

Receives a hash of event names and functions and/or function names, and returns the same hash with the function names replaced with the function references themselves.

var Mn = require('backbone.marionette');

var View = Mn.View.extend({

  initialize: function() {
    var hash = {
      'event:one': 'handleEventOne', // This will become a reference to `this.someFn`
      'event:two': this.someOtherFn
    };

    this.normalizedHash = this.normalizeMethods(hash);

    Mn.bindEvents(this, this, this.normalizedHash);
  },

  destroy: function() {
      Mn.unbindEvents(this, this, this.normalizedHash);
  },

  handleEventOne: function() {
    console.log('event:one was fired');
  },

  handleEventTwo: function() {
    console.log('event:two was fired');
  }

});

Live example