Computed fields for Backbone.Models
Grab the source from the src folder above. Grab the most recent builds
from the links below.
-
Development: backbone.compute.js
-
Production: backbone.compute.min.js
-
Development: backbone.compute.js
-
Production: backbone.compute.min.js
var Model = Backbone.Model.extend({
initialize: function(){
// initialize all of the computed fields for this model
Backbone.Compute(this);
},
// define a computed field.
// tell it what field to `set` on the model
// tell it what fields this one depends on
// give it a callback function to compute the value when any dependent field changes
someField: {
fields: ["f1", "f2"],
compute: function(fields){
return fields.f1 + "-" + fields.f2
}
}
});
var model = new Model({
f1: "foo",
f2: "bar"
});
// get the current value
model.get("someField"); // => "foo-bar"
// re-run the computation, `set` the current value and return it
model.someField(); // => "foo-bar"
// Handle "change" events for the computed field
model.on("change:someField", function(){
// do stuff when the computed field changes
});
// `set` the fields that the computed field depends on
model.set({
f1: "boo",
f2: "far"
});
// get the updated value
model.get("someField"); // => "boo-far"
model.someField(); // => "boo-far"MIT license - see LICENSE.md