#Constructor.js

Constructor.js provides a constructor for constructors.

Why:

because I'd rather do this:

var Car = new Constructor({
  initialize: function(name){
    this.name = name;
  },
  drive: function(){
    this.driving = true;
  }
});

then this:

var Car = function(name){
  this.name = name;
}
Car.prototype = {
  drive: function(){
    this.driving = true;
  }
};

or even better:

var Car = new Constructor(function(){

  this.initialize = function(name){
    this.name = name;
  };

  this.drive = function(){
    this.driving = true;
  };

});

Another class system for JavaScript? Really!?

Constructor.js doesn't attempt to mimic other languages like Ruby. Instead it simply wraps up a common pattern in some tasty syntactic sugar.

A common pattern for inheritance

// before

function Car(name){
  this.name = name;
}

function Truck(name, size){
  Car.apply(this, [name]);
  this.size = size;
}

Truck.prototype = new Car;

// after

var Car = new Constructor({
  initialize: function(name){
    this.name = name;
  }
});

var Truck = new Constructor(Car, {
  initialize: function(name, size){
    this.$super('initialize', [name]);
    this.size = size;
  }
});

Examples

Create a constructor

var Car = new Constructor({
  initialize: function(name){
    this.name = name;
  }
});

new Car instanceof Car;
//-> true

Car() instanceof Car;
//-> true

new Car('hotrod').name === 'hotrod';
//-> true

Inherit from a constructor

var Truck = new Constructor(Car, {
  initialize: function(name, size){
    this.$super('initialize', [name]);
    this.size = size;
  }
});

Truck.superconstructor === Car
//-> true

Truck.prototype.superobject === Car.prototype
//-> true

new Truck instanceof Truck;
//-> true

new Truck() instanceof Car;
//-> true

var lorry = new Truck('lorry', 18);

lorry.name === 'lorry';
//-> true

lorry.size === 18;
//-> true

Inherit from a native object

var Array2 = new Constructor(Array, {
  push: function(){
    this.$super('push', arguments);
    return this;
  }
});
var a2 = new Array2();
a2.push(1,2,3);
//-> a2