实例化对象中不存在作为属性的子类方法

Question

I'm writing a State Pattern, and the methods that are properties of the different states that I have written as subclasses don't seem to exist in the instantiated State object.

Help?

The part of the code that doesn't work is something like this:

var Main,
    Active,
    Inactive;

Main = (function() {
  function Main() {
    // Construct Main object
    this.currentStatus = new Inactive();
  }
  return Main;

})();

Active = (function() {
  function Active() {
    // Construct Active object
  }
  Active.prototype.deactivate = function() {
    // Deactivate
  }
  Active.prototype.activate = function() {
    // Do nothing
  }
  return Active;
})();
Active.prototype = Object.create(Main.prototype);
Active.prototype.constructor = Active;

Inactive = (function() {
  function Inactive() {
    // Construct Inactive object
  }
  Inactive.prototype.deactivate = function() {
    // Do nothing
  }
  Inactive.prototype.activate = function() {
    // Activate
  }
  return Inactive;
})();
Inactive.prototype = Object.create(Main.prototype);
Inactive.prototype.constructor = Inactive;

var object = new Main();

// This doesn't work
object.currentStatus.activate;

Answer 1

There is no activate method in object.currentStatus because you are reassigning Inactive.prototype on line 41. You need to do this before extending the prototype with more methods:

Inactive = (function() {
  function Inactive() {
    // Construct Inactive object
  }

  Inactive.prototype = Object.create(Main.prototype);
  Inactive.prototype.constructor = Inactive;

  Inactive.prototype.deactivate = function() {
    // Do nothing
  }
  Inactive.prototype.activate = function() {
    // Activate
  }
  return Inactive;
})();

Demo: http://jsbin.com/beqofigihu/edit?js,console

Same is true for Active class.