Backprop

A small Backbone plugin that lets you use ECMAScript 5 properties on your Backbone models. Instead of doing:

console.log(mymodel.get('name'));
mymodel.set('name', 'Bob');

with Backprop you can write this instead:

console.log(mymodel.name);
mymodel.name = 'Bob';

You can install it from npm with npm install backprop.

Usage

Initialize the plugin with:

Backprop.monkeypatch(Backbone);

This will replace Backbone.Model.extend with a version that creates the properties, and creates Backbone.property, a function that you can use to define properties on your models.

Then in your models write something like:

var User = Backbone.Model.extend({
    name: Backbone.property({ default: 'Jonas', coerce: String }),
    numFollowers: Backbone.property({ default: 0, coerce: Number });
});

Also, Backprop is CommonJS-friendly, so you can use it in Node or with client-side module systems like Browserify:

var Backprop = require('backprop');

Backbone.property() arguments

Backbone.property takes an optional hash as its only argument, and the following keys are supported to make dealing with properties a bit more pleasant:

default Lets you specify a default value for the property. This will override anything that was set in the defaults hash for this attribute name. Basically just a convenient shorthand so you can keep your default value close to the property definition.

coerce Specify a function that coerces the property's value any time it is set. For example:

var Cat = Backbone.Model.extend({
    name: Backbone.property({ coerce: String }),
    lives: Backbone.property({ coerce: Number })
});
var c = new Cat;

c.name = 42;
console.log(c.name === '42')    // prints true

c.lives = '9';
console.log(c.lives === 9)      // prints true

Running tests

git clone git://github.com/af/backprop.git
cd backprop
npm test

Credits

Partial inspiration came from this gist: https://gist.github.com/dandean/1292057