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 string containing the result of applying the
template using the data
object as the context.
var template = "#some-template";
var data = {foo: "bar"};
var html = Backbone.Marionette.Renderer.render(template, data);
// do something with the HTML here
If you pass a template
that coerces to a falsey value, the
render
method will throw an exception stating that there was no
template provided.
If the template
parameter of the render
function is itself a function,
the renderer treats this as a pre-compiled template and does not try to
compile it again. This allows any view that supports a template
parameter
to specify a pre-compiled template function as the template
setting.
var myTemplate = _.template("<div>foo</div>");
Backbone.Marionette.ItemView.extend({
template: myTemplate
});
The template function does not have to be any specific template engine. It
only needs to be a function that returns valid HTML as a string from the
data
parameter passed to the function.
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
render
method to work however you want:
Backbone.Marionette.Renderer.render = function(template, data){
return $(template).tmpl(data);
};
This implementation will replace the default Underscore.js rendering with jQuery templates rendering.
If you override the render
method and wish to use the
TemplateCache
mechanism, remember to include the code necessary to
fetch the template from the cache in your render
method:
Backbone.Marionette.Renderer.render = function(template, data){
var template = Marionette.TemplateCache.get(template);
// Do something with the template here
};
You can easily replace the standard template rendering functionality with a pre-compiled template, such as those provided by the JST or TPL plugins for AMD/RequireJS.
To do this, just override the render
method to return your executed
template with the data.
Backbone.Marionette.Renderer.render = function(template, data){
return template(data);
};
Then you can specify the pre-compiled template function as your view's
template
attribute:
var myPrecompiledTemplate = _.template("<div>some template</div>");
Backbone.Marionette.ItemView.extend({
template: myPrecompiledTemplate
});