The Renderer
object was extracted from the View
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 Underscore template
using the data
object as the context.
var Mn = require('backbone.marionette');
var template = '#some-template';
var data = {foo: 'bar'};
var html = Mn.Renderer.render(template, data);
// do something with the HTML here
If you pass a template
that coerces to a falsy value -
but not false - 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 Mn = require('backbone.marionette');
var myTemplate = _.template('<div>foo</div>');
Mn.View.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, and View
object or CompositeView object as the optional third 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 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:
var Mn = require('backbone.marionette');
Mn.Renderer.render = function(template, data, view){
template += view.getState();
return $(template).tmpl(data);
};
This implementation will replace the default underscore 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:
var Mn = require('backbone.marionette');
Mn.Renderer.render = function(template, data){
var template = Mn.TemplateCache.get(template);
// Do something with the template here
};
See the Documentation for TemplateCache
for
more detailed information.
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.
var Mn = require('backbone.marionette');
Mn.Renderer.render = function(template, data) {
return template(data);
};
Then you can specify the pre-compiled template function as your view's
template
attribute:
var Mn = require('backbone.marionette');
var myPrecompiledTemplate = _.template('<div>some template</div>');
Mn.View.extend({
template: myPrecompiledTemplate
});
For more information on templates in general, see the Documentation for templates.