Warning: deprecated
Marionette.Callbacks are deprecated, and are scheduled to be removed in the next major release of the library. Instead of Callbacks, you should use promises or events to manage asynchronous logic.
The Callbacks
object assists in managing a collection of callback
methods, and executing them, in an async-safe manner.
There are only two methods:
add
run
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({value: "options"}, someContext);
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 is an optional
parameter that can be any valid JavaScript object.
You can optionally specify the context that you want each callback to be executed with, when adding a callback:
var callbacks = new Backbone.Marionette.Callbacks();
callbacks.add(function(options){
alert("I'm a callback with " + options.value + "!");
// specify callback context as second parameter
}, myContext);
// the `someContext` context is ignored by the above callback
callbacks.run({value: "options"}, someContext);
This will run the specified callback with the myContext
object set as
this
in the callback, instead of someContext
.
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.