demostrate mixins and open class

inheritance.js

// mixin 1
var SuperAbility = {
  dance: function () {
    console.log (this.name + " is dancing...");
  },
  talk: function () {
    console.log ("talking from mixin...");
  }
}
// mixin 2
var SuperIntelligence = {
  think: function () {
    console.log (this.name + " is thinking...");
  }
}

var Animal = function (name) {
  this.name = name;
};

Animal.prototype.walk = function () {
  console.log(this.name + " is walking...");
}

var duck = new Animal("duck");
var dog = new Animal("dog");
dog.walk(); // dog is walking...

// open class
Animal.prototype.talk = function () {
  console.log(this.name + " is barking...");
};

// mixins
// also can extend Animal.prototype so mixins will apply to all animals 
_.extend(dog, SuperAbility, SuperIntelligence);
_.extend(duck, SuperAbility, SuperIntelligence);

// shadowed method
dog.talk(); // talking from mixin

dog.think();

// calling parents method (only when mixin is applied to instance object)
dog.constructor.prototype.talk.apply(dog); // dog is barking..

dog.dance(); // dog is dancing...

duck.dance();
duck.think();