Backbone.ReadOnly

A Backbone plugin for creating read-only models and collections.

When a model or collection is read-only:

• Any number of components can share an instance of it, but will be unable to make changes to it. For models, this means not being able to change its attributes. For collections, it means not be able to add or remove models.
• The fetch() method is still available on both models and collections.
• Attempting to call Model.set(), Collection.add, etc. will result in an exception being thrown (i.e. fail loudly).

Lastly, this plugin takes a simplicity over thorough approach. I didn't try to plug every hole. For example, this plugin does nothing to stop access to Backbone.Model.attributes.

Installation

NPM

npm install backbone.readonly --save

Bower

bower install backbone.readonly --save

Example

// If using as a global module (i.e. <script src="backbone.readonly.js"></script>),
// replace "ReadOnly" below with "Backbone.ReadOnly".

// If using as a node module, browserify or AMD,
var ReadOnly = require('backbone.readonly');

//
// Sample Model usage
//

var person = new ReadOnly.Model({id: 1, name: 'Jane Doe'});
person.set('name', 'Janice Doe'); //throws exception

person.on('change', function() {
    //update UI, etc.
});

person.fetch(); //still works

//
// Sample Collection usage
//

var people = new ReadOnly.Collection([person]);
people.add([{id: 2, name: 'John Doe'}]); //throws exception

people.on('update', function() {
    //update UI, etc.
});

people.fetch(); //still works

// When creating a read-only collection, unless otherwise specified, models will
// be an instance of ReadOnly.Model, which helps with:

var active = people.get(1);
active.set('isLoggedIn', true); // fail, clone the model first