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
- Marionette.getOption
- Marionette.triggerMethod
- Marionette.bindEntityEvent
- Marionette.normalizeMethods
- Marionette.normalizeUIKeys
- Marionette.actAsCollection
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 Foo = function(){};
// use Marionette.extend to make Foo extendable, just like other
// Backbone and Marionette objects
Foo.extend = Marionette.extend;
// Now Foo can be extended to create a new type, with methods
var Bar = Foo.extend({
someMethod: function(){ ... }
// ...
});
// Create an instance of Bar
var b = new Bar();Retrieve an object's attribute either directly from the object, or from
the object's this.options, with this.options taking precedence.
var M = Backbone.Model.extend({
foo: "bar",
initialize: function(){
var f = Marionette.getOption(this, "foo");
console.log(f);
}
});
new M(); // => "bar"
new M({}, { foo: "quux" }); // => "quux"This is useful when building an object that can have configuration set in either the object definition or the object's constructor options.
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 M = Backbone.Model.extend({
foo: "bar",
initialize: function(){
var f = Marionette.getOption(this, "foo");
console.log(f);
}
});
new M(); // => "bar"
var f;
new M({}, { foo: f }); // => "bar"In this example, "bar" is returned both times because the second
example has an undefined value for f.
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" functiontriggerMethod("before:close")fires the "onBeforeClose" 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.
This method is used to bind a backbone "entity" (collection/model) to methods on a target object.
Backbone.View.extend({
modelEvents: {
"change:foo": "doSomething"
},
initialize: function(){
Marionette.bindEntityEvents(this, this.model, this.modelEvents);
},
doSomething: function(){
// the "change:foo" event was fired from the model
// respond to it appropriately, here.
}
});The first parameter, target, must have a listenTo method from the
EventBinder object.
The second parameter is the entity (Backbone.Model or Backbone.Collection) 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.
This method can be used to unbind callbacks from entities' (collection/model) events. It's the opposite of bindEntityEvents, 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.
Backbone.View.extend({
modelEvents: {
"change:foo": "doSomething"
},
initialize: function(){
Marionette.bindEntityEvents(this, this.model, this.modelEvents);
},
doSomething: function(){
// the "change:foo" event was fired from the model
// respond to it appropriately, here.
},
onClose: function() {
Marionette.unbindEntityEvents(this, this.model, this.modelEvents);
}
});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.
This function is attached to the Marionette.View prototype by default. To use it from non-View classes you'll need to attach it yourself.
var View = Marionette.ItemView.extend({
initialize: function() {
this.someFn = function() {};
this.someOtherFn = function() {};
var hash = {
eventOne: "someFn", // This will become a reference to `this.someFn`
eventTwo: this.someOtherFn
};
this.normalizedHash = this.normalizeMethods(hash);
}
});This method allows you to use the @ui. syntax within a given key for triggers and events hashes. It
swaps the @ui. reference with the associated selector.
var hash = {
'click @ui.list': 'myCb'
};
var ui = {
'list': 'ul'
};
// This sets 'click @ui.list' to be 'click ul' in the newHash object
var newHash = Marionette.normalizeUIKeys(hash, ui);Utility function for mixing in underscore collection behavior to an object.
It works by taking an object and a property field, in this example 'list', and appending collection functions to the object so that it can delegate collection calls to its list.
obj = {
list: [1, 2, 3]
}
Marionette.actAsCollection(obj, 'list');
var double = function(v){ return v*2};
console.log(obj.map(double)); // [2, 4, 6]var Func = function(list) {
this.list = list;
};
Marionette.actAsCollection(Func.prototype, 'list');
var func = new Func([1,2,3]);
var double = function(v){ return v*2};
console.log(func.map(double)); // [2, 4, 6]The first parameter is the object that will delegate underscore collection methods.
The second parameter is the object field that will hold the list.