ko.ninja

Models

Defining a Model

The Model class is used to represent data objects. A model instance typically represents a row in a remote database or some other form of persistent storage.

var Person = ko.Model.extend({
	'model': 'persons',
	'idAttribute': 'id',
	'attributes': {
		'first_name': {
			'type': 'string',
			'maxLength': 20,
			'required': true
		},
		'last_name': {
			'type': 'string',
			'maxLength': 20,
			'required': true
		},
		'email': {
			'type': 'email'
		}
	},
	'observables': {
		'full_name': function() {
			return this.first_name() + ' ' + this.last_name();
		}
	},
	'run': function() {
		console.log(this.first_name() + ' is now walking.');
	}
});

Creating a New Record

var person = new Person();
person.set('first_name', 'Chuck');
person.set('last_name', 'Norris');
person.set('email', '[email protected]');
person.save().done(function() {
	// Success.
}).fail(function() {
	// Failure.
});

Retrieving an Existing Record

var person = new Person({
	'id': '0d25fcd5-a76b-47cd-92bc-94d6bc2b8432'
});
person.fetch().done(function() {
	// Success
}).fail(function() {
	// Failure
});

Deleting a Record

person.destroy().done(function() {
	// Success
}).fail(function() {
	// Failure
});

Collections

The Collection class is used to represent a collection of model instances (e.g. a group of people, etc...). Models can easily be added to and removed from the collection. Methods can also be defined on the collection level that allow you to operate on multiple models with a single call.

Defining a Collection

var People = ko.Collection.extend({
	'model': Person,
	'getNames': function() {
		var names = [];
		_.each(this.models(), function(person) {
			names.push(person.full_name());
		});
		return names;
	}
});

var people = new People();

Adding a Record to a Collection

people.push(person);

Removing a Record from a Collection

people.remove(person);

The Collection Observable

The underlying mechanism for tracking the models that belong to a particular collection is a Knockout.JS Observable Array. The observable array can be accessed directly as shown below:

var obs = people.models;

As with any other Knockout.JS observable, you can subscribe to this value to watch for future changes:

people.models.subscribe(function(data) {
});