Try this:
// Create car model
var Car = Backbone.RelationalModel.extend({
});
// Create engine model
var Engine = Backbone.RelationalModel.extend({
relations: [{
type: 'HasMany',
key: 'cars',
relatedModel: Car,
reverseRelation: {
key: 'engine'
}
}]
});
// Create engine instance
var engine = new Engine({
id : 1,
type : 'electric'
});
// Create car instance
var car = new Car({
id : 1,
brand : 'Toyota',
engine : 1
});
// get 'electric'
console.log(car.get('engine').get('type'));