This is the primary documentation for the Marionette API. Here, you'll find detailed discussion of the individual pieces of Marionette, the basics of how to use them, and how to customize them to work in manners that fit your applicaton's needs.
Please note that this is document is rather dry - it's meant to be a reference for those that just need a reference. If you're looking for an introduction and/or examples on how to get started, please see the Wiki.
These are the strings that you can pull to make your puppet dance:
- Backbone.Marionette.Application: An application object that starts your app via initializers, and more
- Backbone.Marionette.Application.module: Create modules and sub-modules within the application
- Backbone.Marionette.AppRouter: Reduce your routers to nothing more than configuration
- Backbone.Marionette.View: The base View type that other Marionette views extend from (not intended to be used directly)
- Backbone.Marionette.ItemView: A view that renders a single item
- Backbone.Marionette.CollectionView: A view that iterates over a collection, and renders individual
ItemView
instances for each model - Backbone.Marionette.CompositeView: A collection view and item view, for rendering leaf-branch/composite model hierarchies
- Backbone.Marionette.Layout: A view that renders a layout and creates region managers to manage areas within it
- Backbone.Marionette.Region: Manage visual regions of your application, including display and removal of content
- Backbone.Marionette.EventAggregator: An extension of Backbone.Events, to be used as an event-driven or pub-sub tool
- Backbone.Marionette.BindTo: An event binding manager, to facilitate binding and unbinding of events
- Backbone.Marionette.Renderer: Render templates with or without data, in a consistent and common manner
- Backbone.Marionette.TemplateCache: Cache templates that are stored in
<script>
blocks, for faster subsequent access - Backbone.Marionette.Callbacks: Manage a collection of callback methods, and execute them as needed
The Application
, Region
, ItemView
and CollectionView
use the
extend
syntax and functionality from Backbone, allowing you to define new
versions of these objects with custom behavior.
The Backbone.Marionette.Application
object is the hub of your composite
application. It organizes, initializes and coordinates the various pieces of your
app. It also provides a starting point for you to call into, from your HTML
script block or from your JavaScript files directly if you prefer to go that
route.
The Application
is meant to be instantiated directly, although you can extend
it to add your own functionality.
MyApp = new Backbone.Marionette.Application();
Your application needs to do useful things, like displaying content in your
regions, starting up your routers, and more. To accomplish these tasks and
ensure that your Application
is fully configured, you can add initializer
callbacks to the application.
MyApp.addInitializer(function(options){
// do useful stuff here
var myView = new MyView({
model: options.someModel
});
MyApp.mainRegion.show(myView);
});
MyApp.addInitializer(function(options){
new MyAppRouter();
Backbone.history.start();
});
These callbacks will be executed when you start your application,
and are bound to the application object as the context for
the callback. In other words, this
is the MyApp
object, inside
of the initializer function.
The options
parameters is passed from the start
method (see below).
Initializer callbacks are guaranteed to run, no matter when you
add them to the app object. If you add them before the app is
started, they will run when the start
method is called. If you
add them after the app is started, they will run immediately.
The Application
object raises a few events during its lifecycle. These events
can be used to do additional processing of your application. For example, you
may want to pre-process some data just before initialization happens. Or you may
want to wait until your entire application is initialized to start the
Backbone.history
.
The events that are currently triggered, are:
- "initialize:before": fired just before the initializers kick off
- "initialize:after": fires just after the initializers have finished
- "start": fires after all initializers and after the initializer events
MyApp.bind("initialize:before", function(options){
options.moreData = "Yo dawg, I heard you like options so I put some options in your options!"
});
MyApp.bind("initialize:after", function(options){
if (Backbone.history){
Backbone.history.start();
}
});
The options
parameter is passed through the start
method of the application
object (see below).
Once you have your application configured, you can kick everything off by
calling: MyApp.start(options)
.
This function takes a single optional parameter. This parameter will be passed to each of your initializer functions, as well as the initialize events. This allows you to provide extra configuration for various parts of your app, at initialization/start of the app, instead of just at definition.
var options = {
something: "some value",
another: "#some-selector"
};
MyApp.start(options);
Every application instance comes with an instance of Marionette.EventAggregator
called app.vent
.
MyApp = new Backbone.Marionette.Application();
MyApp.vent.on("foo", function(){
alert("bar");
});
MyApp.vent.trigger("foo"); // => alert box "bar"
See the Marionette.EventAggregator
documentation below, for more details.
Marionette allows you to define a module within your application, including sub-modules hanging from that module.
This is useful for creating modular, encapsulated applications that are be split apart in to multiple files.
By default, every module that you define and add to your
application, including sub-modules, is a new Application
object instance. This allows you to have unlimited
sub-modules and nesting. It also means you have all of the
features and functionality of an Application
object for
each module.
A module is defined directly from an Application object, and creates another Application object with the specified name:
var MyApp = new Backbone.Marionette.Application();
var myModule = MyApp.module("MyModule");
MyApp.MyModule; // => a new Marionette.Application object
myModule === MyApp.MyModule; // => true
If you specify the same module name more than once, the first instance of the module will be retained and a new instance will not be created.
You can specify a callback function to provide a definition
for the module. Module definitions are invoked immediately
on calling module
method.
The module definition callback will receive 6 parameters:
- The module itself
- The Parent module or Application object that
.module
was called from - Backbone
- Backbone.Marionette
- jQuery
- Underscore
You can add functions and data directly to your module to make them publicly accessible. You can also add private functions and data by using locally scoped variables.
MyApp.module("MyModule", function(MyModule, MyApp, Backbone, Marionette, $, _){
// Private Data And Functions
// --------------------------
var myData = "this is private data";
var myFunction = function(){
console.log(myData);
}
// Public Data And Functions
// -------------------------
MyModule.someData = "public data";
MyModule.someFunction = function(){
console.log(MyModule.someData);
}
});
console.log(MyApp.MyModule.someData); //=> public data
MyApp.MyModule.someFunction(); //=> public data
Sub-modules can be defined in a number of ways.
You can define a module, and then later use that module to define sub-modules:
MyModule = MyApp.module("MyModule");
MyModule.module("SubModule");
MyApp.MyModule.SubModule; // => a valid module object
Or you can define an entire hierarchy of modules and sub-modules all at once:
MyApp.module("Parent.Child.GrandChild");
MyApp.Parent.Child.GrandChild; // => a valid module object
When defining sub-modules using the dot-notation, the parent modules do not need to exist. They will be created for you if they don't exist. If they do exist, though, the existing module will be used instead of creating a new one.
As each module is an Application
object instance,
initializer functions can be registerd on your modules. There
is no automatic starting of these modules, though. If you
wish to use the module's initializer functions, you must
manually call the module's start method.
MyApp.module("MyModule", function(MyModule){
MyModule.addInitializer(function(){
console.log("I'm a module initializer!");
});
});
MyApp.MyModule.start(); // => "I'm a module initializer!"
If you want to override the module object with your own object, you can do that by returning an object from the module definition:
MyApp.module("MyModule", function(){
var customModule = {};
return customModule;
});
MyApp.MyModule; // => the 'customModule' object
Note: When you override a module with a custom object,
you will not be able to add sub-modules to it using the
module
fuction, as this function will not exist on your
module (unless you add it yourself).
Sometimes a module gets to be too long for a single file. In this case, you can split a module definition across multiple files:
MyApp.module("MyModule", function(MyModule){
MyModule.definition1 = true;
});
MyApp.module("MyModule", function(MyModule){
MyModule.definition2 = true;
});
MyApp.MyModule.definition1; //=> true
MyApp.MyModule.definition2; //=> true
Note that if you return a custom module from your module definitions, the last module definition to return, wins.
MyApp.module("MyModule", function(MyModule){
a = {};
a.foo = "bar";
return a;
});
MyApp.module("MyModule", function(MyModule){
b = {};
b.foo = "I'm overriding you!";
return b;
});
MyApp.MyModule.foo; //=> "I'm overriding you!"
Reduce the boilerplate code of handling route events and then calling a single method on another object. Have your routers configured to call the method on your object, directly.
Configure an AppRouter with appRoutes
. The route definition is passed on to Backbone's standard routing
handlers. This means that you define routes like you normally would. Instead of providing a callback
method that exists on the router, though, you provide a callback method that exists on the controller
that you specify for the router instance (see below).
MyRouter = Backbone.Marionette.AppRouter.extend({
appRoutes: {
"some/route": "someMethod"
}
});
You can also add standard routes to an AppRouter, with methods on the router.
App routers can only use one controller
object. You can either specify this
directly in the router definition:
someController = {
someMethod: function(){ /*...*/ }
};
Backbone.Marionette.AppRouter.extend({
controller: someController
});
Or in a parameter to the contructor:
myObj = {
someMethod: function(){ /*...*/ }
};
new MyRouter({
controller: myObj
});
Or
The object that is used as the controller
has no requirements, other than it will
contain the methods that you specified in the appRoutes
.
It is recommended that you divide your controller objects into smaller pieces of related functionality and have multiple routers / controllers, instead of just one giant router and controller.
Region managers provide a consistent way to manage your views and show / close them in your application. They use a jQuery selector to show your views in the correct place. They also call extra methods on your views to facilitate additional functionality.
Regions can be added to the application by calling the addRegions
method on
your application instance. This method expects a single hash parameter, with
named regions and either jQuery selectors or Region
objects. You may
call this method as many times as you like, and it will continue adding regions
to the app.
MyApp.addRegions({
mainRegion: "#main-content",
navigationRegion: "#navigation"
});
As soon as you call addRegions
, your region managers are available on your
app object. In the above example MyApp.mainRegion
and MyApp.navigationRegion
would be available for use immediately.
If you specify the same region name twice, the last one in wins.
You can specify an el
for the region manager to manage at the time
that the region manager is instantiated:
var mgr = new Backbone.Marionette.Region({
el: "#someElement"
});
Once a region manager has been defined, you can call the show
and close
methods on it to render and display a view, and then
to close that view:
var myView = new MyView();
// render and display the view
MyApp.mainRegion.show(myView);
// closes the current view
MyApp.mainRegion.close();
If you replace the current view with a new view by calling show
,
it will automatically close the previous view.
// show the first view
var myView = new MyView();
MyApp.mainRegion.show(myView);
// replace view with another. the
// `close` method is called for you
var anotherView = new AnotherView();
MyApp.mainRegion.show(anotherView);
You can specify a second parameter to the show
method,
which will be used to determine how the HTML from the view's
el
is attached to the DOM region that is being managed.
The options include any valid jQuery DOM object method, such
as html
, text
, append
, etc.
MyApp.mainRegion.show(myView, "append");
This example will use jQuery's $.append
function to append
the new view to the current HTML.
WARNING: Be careful when using this feature, as the view you are replacing may not be managed / closed correctly as a result. This can cause unexpected behavior, memory leaks or other problems. Use At Your Own Risk
There are some scenarios where it's desirable to attach an existing view to a region manager, without rendering or showing the view, and without replacing the HTML content of the region. For example, SEO and accessibiliy often need HTML to be generated by the server, and progressive enhancement of the HTML.
There are two ways to accomplish this:
- set the
currentView
in the region manager's constructor - call
attachView
on the region manager instance
var myView = new MyView({
el: $("#existing-view-stuff")
});
var manager = new Backbone.Marionette.Region({
el: "#content",
currentView: myView
});
MyApp.addRegions({
someRegion: "#content"
});
var myView = new MyView({
el: $("#existing-view-stuff")
});
MyApp.someRegion.attachView(myView);
A region manager will raise a few events during its showing and closing of views:
- "view:show" - when the view has been rendered and displayed
- "onShow" - called on the region when the view has been rendered
- "view:closed" - when the view has been closed
You can bind to these events and add code that needs to run with your region manager, opening and closing views.
MyApp.mainRegion.on("view:show", function(view){
// manipulate the `view` or do something extra
// with the region manager via `this`
});
MyApp.mainRegion.on("view:closed", function(view){
// manipulate the `view` or do something extra
// with the region manager via `this`
});
MyRegion = Backbone.Marionette.Region.extend({
// ...
onShow: function(view){
// the `view` has been shown
}
});
The region manager will call an onShow
method on the view
that was displayed. It will also trigger a "show" event
from the view:
MyView = Backbone.View.extend({
onShow: function(){
// the view has been shown
}
});
view = new MyView();
view.on("show", function(){
// the view has been shown.
});
MyApp.mainRegion.show(view);
You can define a custom region manager by extending from
Region
. This allows you to create new functionality,
or provide a base set of functionality for your app.
Once you define a region manager type, you can still call the
addRegions
method. Specify the region manager type as the
value - not an instance of it, but the actual constructor
function.
var FooterRegion = Backbone.Marionette.Region.extend({
el: "#footer"
});
MyApp.addRegions({footerRegion: FooterRegion});
Note that if you define your own Region
object, you must provide an
el
for it. If you don't, you will receive an runtime exception saying that
an el
is required.
There may be times when you want to add a region manager to your
application after your app is up and running. To do this, you'll
need to extend from Region
as shown above and then use
that constructor function on your own:
var SomeRegion = Backbone.Marionette.Region.extend({
el: "#some-div",
initialize: function(options){
// your init code, here
}
});
MyApp.someRegion = new SomeRegion();
MyApp.someRegion.show(someView);
You can optionally add an initialize
function to your Region
definition as shown in this example. It receives the options
that were passed to the constructor of the Region, similar to
a Backbone.View.
The region manager show
method takes advantage of jQuery's
deferred cababilities, allowing for some very advanced techniques
to be used for rendering views.
To use a deferred, a view that is shown via a region manager
must return a jQuery deferred object from the render
method:
DeferredView = Backbone.View.extend({
render: function(){
var that = this;
var data = this.serializeData();
var dfd = jQuery.Deferred();
this.getTemplate(function(template){
var html = that.renderTemplate(template, data);
that.$el.html(html);
if (that.onRender){
that.onRender();
}
dfd.resolve();
});
return dfd.promise();
}
});
var view = new DeferredView();
MyApp.mainRegion.show(view);
The region manager will wait until the deferred object is resolved
before it attached the view's el
to the DOM and displays it.
Marionette has a base Marionette.View
type that other views extend from.
This base view provides some common and core functionality for
other views to take advantage of.
Note: The Marionette.View
type is not intended to be
used directly. It exists as a base view for other view types
to be extended from, and to provide a common location for
behaviors that are shared across all views.
Views can define a set of triggers
as a hash, which will
convert a DOM event in to a view.trigger
event.
The left side of the hash is a standard Backbone.View DOM event configuration, while the right side of the hash is the view event that you want to trigger from the view.
MyView = Backbone.Marionette.ItemView.extend({
// ...
triggers: {
"click .do-something": "something:do:it"
}
});
view = new MyView();
view.render();
view.on("something:do:it", function(){
alert("I DID IT!");
});
// "click" the 'do-something' DOM element to
// demonstrate the DOM event conversion
view.$(".do-something").trigger("click");
The result of this is an alert box that says, "I DID IT!"
You can also specify the triggers
as a function that
returns a hash of trigger configurations
Backbone.Marionette.CompositeView.extend({
triggers: function(){
return {
"click .that-thing": "that:i:sent:you"
};
}
});
Triggers work with all View types that extend from the base Marionette.View.
The serializeData
method will serialize a view's model or
collection - with precedence given to collections. That is,
if you have both a collection and a model in a view, calling
the serializeData
method will return the serialized
collection.
There are times when a view's template needs to have some logic in it, and the view engine itself will not provide an easy way to accomplish this. For example, Underscore templates do not provide a helper method mechanism while Handlebars templates do.
A templateHelpers
attribute can be applied to any View object
that uses the serializeData
method - including ItemViews,
Layouts and CompositeViews. When this attribute is present,
it's contents will be mixed in to the data object that comes
back from the serializeData
method for you. This will
allow you to create helper methods that can be called from
within your templates.
<script id="my-template" type="text/html">
I think that <%= showMessage() %>
</script>
MyView = Backbone.Marionette.ItemView.extend({
template: "#my-template",
templateHelpers: {
showMessage: function(){
return this.name + " is the coolest!"
}
}
});
model = new Backbone.Model({name: "Backbone.Marionette"});
view = new MyView();
view.render(); //=> "I think that Backbone.Marionette is the coolest!";
In order to access data from within the helper methods, you
need to prefix the data you need with this
. Doing that will
give you all of the methods and attributes of the serialized
data object, including the other helper methods.
templateHelpers: {
something: function(){
return "Do stuff with " + this.name + " because it's awesome.";
}
}
You can specify an object literal (as shown above), a reference
to an object literal, or a function as the templateHelpers
.
If you specify a function, the function will be invoked with the current view instance as the context of the function. The function must return an object that can be mixed in to the data for the view.
Backbone.Marionette.ItemView.extend({
templateHelpers: function(){
return {
foo: function(){ /* ... */ }
}
}
});
Formerly known as CompositeRegion
.
A Layout
is a specialized hybrid between an ItemView
and
a collection of Region
objects, used for rendering an application
layout with multiple sub-regions to be managed by specified region managers.
A layout manager can also be used as a composite-view to aggregate multiple views and sub-application areas of the screen where multiple region managers need to be attached to dynamically rendered HTML.
The Layout
extends directly from ItemView
and adds the ability
to specify regions
which become Region
instances that are attached
to the layout.
<script id="layout-template" type="text/template">
<section>
<navigation id="menu">...</navigation>
<article id="content">...</navigation>
</section>
</script>
AppLayout = Backbone.Marionette.Layout.extend({
template: "#layout-template",
regions: {
menu: "#menu",
content: "#content"
}
});
var layout = new AppLayout();
layout.render();
Once you've rendered the layout, you now have direct access to all of the specified regions as region managers.
layout.menu.show(new MenuView());
layout.content.show(new MainContentView());
Since the Layout
extends directly from ItemView
, it
has all of the core functionality of an item view. This includes
the methods necessary to be shown within an existing region manager.
MyApp = new Backbone.Marionette.Application();
MyApp.addRegions({
mainRegion: "#main"
});
var layout = new AppLayout();
MyApp.mainRegion.show(layout);
layout.show(new MenuView());
You can nest layouts into region managers as deeply as you want. This provides for a well organized, nested view structure.
When you are finished with a layout, you can call the
close
method on it. This will ensure that all of the region managers
within the layout are closed correctly, which in turn
ensures all of the views shown within the regions are closed correctly.
If you are showing a layout within a parent region manager, replacing the layout with another view or another layout will close the current one, the same it will close a view.
All of this ensures that layouts and the views that they contain are cleaned up correctly.
It's common to use a Layout
to represent a sub-application in a
larger overall application. Often the components of the sub-application need
to communicate with each other without allowing the other parts of the larger
application in on the communication. To facilitate this, the layout manager
includes an event aggregator, vent
.
var layout = new MyAppLayout();
layout.vent.trigger("stuff:was:done");
An ItemView
is a view that represents a single item. That item may be a
Backbone.Model
or may be a Backbone.Collection
. Whichever it is, though, it
will be treated as a single item.
An item view has a render
method built in to it, and uses the
Renderer
object to do the actual rendering.
The render
function of the item view will return a jQuery
promise
object.
You should provide a template
attribute on the item view, which
will be either a jQuery selector:
MyView = Backbone.Marionette.ItemView.extend({
template: "#some-template"
});
new MyView().render().done(function(){
// the view is done rendering. do stuff here
});
or a function that returns a jQuery selector:
MyView = Backbone.Marionette.ItemView.extend({
template: function(){
if (this.model.get("foo")){
return "#some-template";
} else {
return "#a-different-template";
}
}
});
new MyView().render().done(function(){
// the view is done rendering. do stuff here
});
There are several callback methods that are called for an ItemView. These methods are intended to be handled within the view definition, directly.
Before an ItemView is rendered a beforeRender
method will be called
on the view.
Backbone.Marionette.ItemView.extend({
beforeRender: function(){
// set up final bits just before rendering the view's `el`
}
});
After the view has been rendered, a onRender
method will be called.
You can implement this in your view to provide custom code for dealing
with the view's el
after it has been rendered:
Backbone.Marionette.ItemView.extend({
onRender: function(){
// manipulate the `el` here. it's already
// been rendered, and is full of the view's
// HTML, ready to go.
}
});
A beforeClose
method will be called on the view, just prior
to closing it:
Backbone.Marionette.ItemView.extend({
beforeClose: function(){
// manipulate the `el` here. it's already
// been rendered, and is full of the view's
// HTML, ready to go.
}
});
An onClose
method will be called on the view, after closing it.
Backbone.Marionette.ItemView.extend({
onClose: function(){
// custom closing and cleanup goes here
}
});
There are several events that are triggers by an ItemView
, which
allow code outside of a view to respond to what's happening with
the view.
An "item:before:render" event will be triggered just before the view is rendered
MyView = Backbone.Marionette.ItemView.extend({...});
var myView = new MyView();
myView.on("item:before:render", function(){
alert("the view is about to be rendered");
});
An "item:rendered" event will be triggered just after the view has been rendered.
MyView = Backbone.Marionette.ItemView.extend({...});
var myView = new MyView();
myView.on("item:rendered", function(){
alert("the view was rendered!");
});
myView.on("render", function(){
alert("the view was rendered!");
});
An "item:before:close" event will be triggered just prior to the
view closing itself. This event fires when the close
method of
the view is called.
MyView = Backbone.Marionette.ItemView.extend({...});
var myView = new MyView();
myView.on("item:before:close", function(){
alert("the view is about to be closed");
});
myView.close();
An "item:closed" event will be triggered just after the
view closes. This event fires when the close
method of
the view is called.
MyView = Backbone.Marionette.ItemView.extend({...});
var myView = new MyView();
myView.on("item:closed", function(){
alert("the view is closed");
});
myView.close();
Item views will serialize a model or collection, by default, by
calling .toJSON
on either the model or collection. If both a model
and collection are attached to an item view, the model will be used
as the data source. The results of the data serialization will be passed to the template
that is rendered.
If the serialization is a model, the results are passed in directly:
var myModel = new MyModel({foo: "bar"});
new MyItemView({
template: "#myItemTemplate",
model: myModel
});
MyItemView.render();
<script id="myItemTemplate" type="template">
Foo is: <%= foo %>
</script>
If the serialization is a collection, the results are passed in as an
items
array:
var myCollection = new MyCollection([{foo: "bar"}, {foo: "baz"}]);
new MyItemView({
template: "#myCollectionTemplate",
collection: myCollection
});
MyItemView.render();
<script id="myCollectionTemplate" type="template">
<% _.each(items, function(item){ %>
Foo is: <%= foo %>
<% }); %>
</script>
If you need custom serialization for your data, you can provide a
serializeData
method on your view. It must return a valid JSON
object, as if you had called .toJSON
on a model or collection.
Backbone.Marionette.ItemView.extend({
serializeData: function(){
return {
"some attribute": "some value"
}
}
});
ItemView extends Marionette.BindTo
. It is recommended that you use
the bindTo
method to bind model and collection events.
MyView = Backbone.Marionette.ItemView.extend({
initialize: function(){
this.bindTo(this.model, "change:foo", this.modelChanged);
this.bindTo(this.collection, "add", this.modelAdded);
},
modelChanged: function(model, value){
},
modelAdded: function(model){
}
});
The context (this
) will automatically be set to the view. You can
optionally set the context by passing in the context object as the
4th parameter of bindTo
.
ItemView implements a close
method, which is called by the region
managers automatically. As part of the implementation, the following
are performed:
- unbind all
bindTo
events - unbind all custom view events
- unbind all DOM events
- remove
this.el
from the DOM - call an
onClose
event on the view, if one is provided
By providing an onClose
event in your view definition, you can
run custom code for your view that is fired after your view has been
closed and cleaned up. This lets you handle any additional clean up
code without having to override the close
method.
Backbone.Marionette.ItemView.extend({
onClose: function(){
// custom cleanup or closing code, here
}
});
The CollectionView
will loop through all of the models in the
specified collection, render each of them using a specified itemView
,
then append the results of the item view's el
to the collection view's
el
.
There are several callback methods that can be provided on a
CollectionView
. If they are found, they will be called by the
view's base methods. These callback methods are intended to be
handled within the view definition directly.
A beforeRender
callback will be called just prior to rendering
the collection view.
Backbone.Marionette.CollectionView.extend({
beforeRender: function(){
// do stuff here
}
});
After the view has been rendered, a onRender
method will be called.
You can implement this in your view to provide custom code for dealing
with the view's el
after it has been rendered:
Backbone.Marionette.CollectionView.extend({
onRender: function(){
// do stuff here
}
});
This method is called just before closing the view.
Backbone.Marionette.CollectionView.extend({
beforeClose: function(){
// do stuff here
}
});
This method is called just after closing the view.
Backbone.Marionette.CollectionView.extend({
onClose: function(){
// do stuff here
}
});
There are several events that will be triggered during the life of a collection view. These are intended to be handled from code external to the view.
Triggers just prior to the view being rendered
MyView = Backbone.Marionette.CollectionView.extend({...});
var myView = new MyView();
myView.on("collection:before:render", function(){
alert("the collection view is about to be rendered");
});
myView.render();
A "collection:rendered" event will also be fired. This allows you to add more than one callback to execute after the view is rendered, and allows parent views and other parts of the application to know that the view was rendered.
MyView = Backbone.Marionette.CollectionView.extend({...});
var myView = new MyView();
myView.on("render", function(){
alert("the collection view was rendered!");
});
myView.on("collection:rendered", function(){
alert("the collection view was rendered!");
});
myView.render();
Triggered just before closing the view.
MyView = Backbone.Marionette.CollectionView.extend({...});
var myView = new MyView();
myView.on("collection:before:close", function(){
alert("the collection view is about to be closed");
});
myView.close();
Triggered just after closing the view.
MyView = Backbone.Marionette.CollectionView.extend({...});
var myView = new MyView();
myView.on("collection:closed", function(){
alert("the collection view is now closed");
});
myView.close();
When an item view within a collection view triggers an event, that event will bubble up through the parent collection view, with "itemview:" prepended to the event name.
That is, if a child view triggers "do:something", the parent collection view will then trigger "itemview:do:something".
// set up basic collection
var myModel = new MyModel();
var myColelction = new MyCollection();
myCollection.add(myModel);
// get the collection view in place
colView = new CollectionView({
collection: myCollection
});
colView.render();
// bind to the collection view's events that were bubbled
// from the child view
colView.on("itemview:do:something", function(childView, msg){
alert("I said, '" + msg + "'");
});
// hack, to get the child view and trigger from it
var childView = colView.children[myModel.cid];
childView.trigger("do:something", "do something!");
The result of this will be an alert box that says "I said, 'do something!'".
Also note that you would not normally grab a reference to the child view the way this is showing. I'm merely using that hack as a way to demonstrate the event bubbling. Normally, you would have your item view listening to DOM events or model change events, and then triggering an event of it's own based on that.
The render
method of the collection view is responsible for
rendering the entire collection. It loops through each of the
items in the collection and renders them individually as an
itemView
.
The render
method returns a jQuery deferred object, allowing
you to know when the rendering completes. This deferred object
is resolved after all of the child views have been rendered.
MyCollectionView = Backbone.Marionette.CollectionView.extend({...});
new MyCollectionView().render().done(function(){
// all of the children are now rendered. do stuff here.
});
Specify an itemView
in your collection view definition. This must be
a Backbone view object definition (not instance). It can be any
Backbone.View
or be derived from Marionette.ItemView
.
MyItemView = Backbone.Marionette.ItemView.extend({});
Backbone.Marionette.CollectionView.extend({
itemView: MyItemView
});
Alternatively, you can specify an itemView
in the options for
the constructor:
MyCollectionView = Backbone.Marionette.CollectionView.extend({...});
new MyCollectionView({
itemView: MyItemView
});
If you do not specify an itemView
, an exception will be thrown
stating that you must specify an itemView
.
The collection view binds to the "add", "remove" and "reset" events of the collection that is specified.
When the collection for the view is "reset", the view will call render
on
itself and re-render the entire collection.
When a model is added to the collection, the collection view will render that one model in to the collection of item views.
When a model is removed from a collection (or destroyed / deleted), the collection view will close and remove that model's item view.
If you need to re-render the entire collection, you can call the
view.render
method. This method takes care of closing all of
the child views that may have previously been opened.
By default the collection view will call jQuery's .append
to
move the HTML contents from the item view instance in to the collection
view's el
.
You can override this by specifying an appendHtml
method in your
view definition. This method takes two parameters and has no return
value.
Backbone.Marionette.CollectionView.extend({
appendHtml: function(collectionView, itemView){
collectionView.$el.prepend(itemView.el);
}
});
The first parameter is the instance of the collection view that will receive the HTML from the second parameter, the current item view instance.
CollectionView implements a close
method, which is called by the
region managers automatically. As part of the implementation, the
following are performed:
- unbind all
bindTo
events - unbind all custom view events
- unbind all DOM events
- unbind all item views that were rendered
- remove
this.el
from the DOM - call an
onClose
event on the view, if one is provided
By providing an onClose
event in your view definition, you can
run custom code for your view that is fired after your view has been
closed and cleaned up. This lets you handle any additional clean up
code without having to override the close
method.
Backbone.Marionette.CollectionView.extend({
onClose: function(){
// custom cleanup or closing code, here
}
});
A CompositeView
extends from CollectionView to be used as a
composite view for scenarios where it should represent both a
branch and leaf in a tree structure, or for scenarios where a
collection needs to be rendered within a wrapper template.
For example, if you're rendering a treeview control, you may want to render a collection view with a model and template so that it will show a parent item with children in the tree.
You can specify a modelView
to use for the model. If you don't
specify one, it will default to the Marionette.ItemView
.
CompositeView = Backbone.Marionette.CompositeView.extend({
template: "#leaf-branch-template"
});
new CompositeView({
model: someModel,
collection: someCollection
});
For more examples, see my blog post on using the composite view
A composite view returns a jQuery deferred object from the
render
method. This allows you to know when the rendering for
the entire composite structure has been completed.
MyComp = Backbone.Marionette.CompositeView.extend({...});
myComp = new MyComp().render().done(function(){
// the entire composite is now rendered. do stuff here
});
When a CompositeView
is rendered, the model
will be rendered
with the template
that the view is configured with. You can
override the template by passing it in as a constructor option:
new MyComp({
template: "#some-template"
});
The default rendering mode for a CompositeView
assumes a
hierarchical, recursive structure. If you configure a composite
view without specifying an itemView
, you'll get the same
composite view type rendered for each item in the collection. If
you need to override this, you can specify a itemView
in the
composite view's definition:
var ItemView = Backbone.Marionette.ItemView.extend({});
var CompView = Backbone.Marionette.CompositeView.extend({
itemView: ItemView
});
The model and collection for the composite view will re-render themselves under the following conditions:
- When the collection's "reset" event is fired, it will re-render the entire list
- When the collection has a model added to it (the "add" event is fired), it will render that one item to the rendered list
- When the collection has a model removed (the "remove" event is fired), it will remove that one item from the rendered list
You can also manually re-render either or both of them:
- If you want to re-render everything, call the
.render()
method - If you want to re-render the model's view, you can call
.renderModel()
- If you want to re-render the collection's views, you can call
.renderCollection()
During the course of rendering a composite, several events will be triggered:
- "composite:item:rendered" - after the
modelView
has been rendered - "composite:collection:rendered" - after the collection of models has been rendered
- "render" / "composite:rendered" - after everything has been rendered
Additionally, after the composite view has been rendered, an
onRender
method will be called. You can implement this in
your view to provide custom code for dealing with the view's
el
after it has been rendered:
Backbone.Marionette.CompositeView.extend({
onRender: function(){
// do stuff here
}
});
An event aggregator is an application level pub/sub mechanism that allows various pieces of an otherwise segmented and disconnected system to communicate with each other.
Backbone.Marionette provides an event aggregator with each application instance:
MyApp.vent
. You can also instantiate your own event aggregator:
myVent = new Backbone.Marionette.EventAggregator();
Passing an object literal of options to the constructor function will extend the event aggregator with those options:
myVent = new Backbone.Marionette.EventAggregator({foo: "bar"});
myVent.foo // => "bar"
The EventAggregator
extends from the BindTo
object (see below) to easily track
and unbind all event callbacks, including inline callback functions.
The bindTo
method, though, has been proxied to only take 3 arguments. It assumes
that the object being bound to is the event aggregator directly, and does not allow
the bound object to be specified:
vent = new Backbone.Marionette.EventAggregator();
vent.bindTo("foo", function(){
alert("bar");
});
vent.unbindAll();
vent.trigger("foo"); // => nothing. all events have been unbound.
You can use an event aggregator to communicate between various modules of your application, ensuring correct decoupling while also facilitating functionality that needs more than one of your application's modules.
var vent = new Backbone.Marionette.EventAggregator();
vent.bind("some:event", function(){
alert("Some event was fired!!!!");
});
vent.trigger("some:event");
For a more detailed discussion and example of using an event aggregator with Backbone applications, see the blog post: References, Routing, and The Event Aggregator: Coordinating Views In Backbone.js
The BindTo
object provides event binding management and facilitates simple
event binding and unbinding for any object that extends from Backbone.Events
.
var binder = _.extend({}, Backbone.Marionette.BindTo);
var model = new MyModel();
var handler = {
doIt: function(){}
}
binder.bindTo(model, "change:foo", handler.doIt);
You can optionally specify a 4th parameter as the context in which the callback method for the event will be executed:
binder.bindTo(model, "change:foo", someCallback, someContext);
When you call bindTo
, it returns a "binding" object that can be
used to unbind from a single event with the unbindFrom
method:
var binding = binder.bindTo(model, "change:foo", someCallback, someContext);
// later in the code
binder.unbindFrom(binding);
This will unbind the event that was configured with the binding object, and remove it from the BindTo bindings.
You can call unbindAll
to unbind all events that were bound with the
bindTo
method:
binder.unbindAll();
This even works with in-line callback functions.
The Renderer
object was extracted from the ItemView
rendering
process, in order to create a consistent and re-usable method of
rendering a template with or without data.
The basic usage of the Renderer
is to call the render
method.
This method returns a jQuery promise
object, which will provide
the HTML that was rendered when it resolves.
var template = "#some-template";
var data = {foo: "bar"};
var render = Backbone.Marionette.Renderer.render(template, data);
render.done(function(html){
// do something with the HTML here
});
By default, the renderer will take a jQuery selector object as
the first parameter, and a JSON data object as the optional
second parameter. It then uses the TemplateCache
to load the
template by the specified selector, and renders the template with
the data provided (if any) using Underscore.js templates.
If you wish to override the way the template is loaded, see
the TemplateCache
object.
If you wish to override the template engine used, change the
renderTemplate
method to work however you want:
Backbone.Marionette.Renderer.renderTemplate = function(template, data){
return $(template).tmpl(data);
});
This implementation will replace the default Underscore.js rendering with jQuery templates rendering.
It's common for developers to use RequireJS to pre-load the entire template that is needed. When the template is pre-loaded like this, the use of a jQuery selector is not needed.
If you wish to replace the entire rendering process, based on the
assumption that you will always pre-load the entire template for
your view, it can be done by replacing the render
method on the
Renderer
object:
Backbone.Marionette.Renderer.render = function(template, data){
return _.template(template, data);
};
This will skip the TemplateCache
usage entirely, and all of the
other code that is usually run, and return the compiled template
immediately.
There's a performance hit in replacing the entire render
function of the Renderer
object as shown in the example
above. You should only have to compile a template once, and you should
be caching the pre-compiled template after that.
To accomplish this, avoid replacing the render
function. Instead
use a combination of the renderTemplate
function and the
TemplateCache.loadTemplate
function.
Backbone.Marionette.TemplateCache.loadTemplate = function(template, callback){
// pre-compile the template and store that in the cache.
var compiledTemplate = _.template(template);
callback.call(this, compiledTemplate);
};
Backbone.Marionette.Renderer.renderTemplate = function(template, data){
// because `template` is the pre-compiled template object,
// we only need to execute the template with the data
return template(data);
}
For more information about the TemplateCache.loadTemplate
function,
see the next section of the documentation.
The TemplateCache
provides a cache for retrieving templates
from script blocks in your HTML. This will improve
the speed of subsequent calls to get a template.
To use the TemplateCache
, call it directly. It is not
instantiated like other Marionette objects.
Templates are retrieved using a jQuery selector by default, and are handed back to you via a callback method. The template is returned as a plain string.
Backbone.Marionette.TemplateCache.get("#my-template", function(template){
// use the template here
});
Making multiple calls to get the same template will retrieve the template from the cache on subsequence calls:
var a, b, c;
Backbone.Marionette.TemplateCache.get("#my-template", function(tmpl){a = tmpl});
Backbone.Marionette.TemplateCache.get("#my-template", function(tmpl){b = tmpl});
Backbone.Marionette.TemplateCache.get("#my-template", function(tmpl){c = tmpl});
a === b === c; // => true
The default template retrieval is to select the template contents
from the DOM using jQuery. If you wish to change the way this
works, you can override the loadTemplate
method on the
TemplateCache
object.
Backbone.Marionette.TemplateCache.loadTemplate = function(templateId, callback){
// load your template here, returning it or a deferred
// object that resolves with the template as the only param
}
For example, if you want to load templates asychronously from the
server, instead of from the DOM, you could replace the
loadTemplate
function.
If a "template.html" file exists on the server, with this in it:
<script id="my-template" type="text/template">
<div>some template stuff</div>
</script>
Then the loadTemplate
implementation may look like this:
Backbone.Marionette.TemplateCache.loadTemplate = function(templateId, callback){
var that = this;
var url = templateId + ".html";
$.get(url, function(templateHtml){
var template = $(tmplateHtml).find(templateId);
callback(template);
});
}
This will use jQuery to asynchronously retrieve the template from
the server. When the get
completes, the callback function will
select the template from the resulting HTML and then call the
callback
function to send it in to the template cache and allow
it to be used for rendering.
You can clear one or more, or all items from the cache using the
clear
method. Clearing a template from the cache will force it
to re-load from the DOM (or from the overriden loadTemplate
function) the next time it is retrieved.
If you do not specify any parameters, all items will be cleared from the cache:
Backbone.Marionette.TemplateCache.get("#my-template");
Backbone.Marionette.TemplateCache.get("#this-template");
Backbone.Marionette.TemplateCache.get("#that-template");
// clear all templates from the cache
Backbone.Marionette.TemplateCache.clear()
If you specify one or more parameters, these parameters are assumed
to be the templateId
used for loading / caching:
Backbone.Marionette.TemplateCache.get("#my-template");
Backbone.Marionette.TemplateCache.get("#this-template");
Backbone.Marionette.TemplateCache.get("#that-template");
// clear 2 of 3 templates from the cache
Backbone.Marionette.TemplateCache.clear("#my-template", "#this-template")
If you're using Marionette.ItemView
, you don't need to manually
call the TemplateCache
. Just specify the template
attribute
of your view as a jQuery selector, and the ItemView
will use
the template manager by default.
The Callbacks
object assists in managing a collection of callback
methods, and executing them, in an async-safe manner.
There are only three methods:
add
run
setOptions
The add
method adds a new callback to be executed later.
The run
method executes all current callbacks in, using the
specified context for each of the callbacks, and supplying the
provided options to the callbacks.
var callbacks = new Backbone.Marionette.Callbacks();
callbacks.add(function(options){
alert("I'm a callback with " + options.value + "!");
});
callbacks.run(someContext, {value: "options"});
This example will display an alert box that says "I'm a callback
with options!". The executing context for each of the callback
methods has been set to the someContext
object, which can be
any valid JavaScript object.
The Callbacks
executes each callback in an async-friendly
manner, and can be used to facilitate async callbacks.
The Marionette.Application
object uses Callbacks
to manage initializers (see above).
It can also be used to guarantee callback execution in an event driven scenario, much like the application initializers.