工厂模式

1.简单工厂

/* BicycleShop class. */



var BicycleShop = function() {};

BicycleShop.prototype = {

  sellBicycle: function(model) {

    var bicycle;

    

    switch(model) {

      case 'The Speedster':

        bicycle = new Speedster();

        break;

      case 'The Lowrider':

        bicycle = new Lowrider();

        break;

      case 'The Comfort Cruiser':

      default:

        bicycle = new ComfortCruiser();

    }

    Interface.ensureImplements(bicycle, Bicycle);

    

    bicycle.assemble();

    bicycle.wash();

    

    return bicycle;

  }

};





/* The Bicycle interface. */



var Bicycle = new Interface('Bicycle', ['assemble', 'wash', 'ride', 'repair']);



/* Speedster class. */



var Speedster = function() { // implements Bicycle

  ...

};

Speedster.prototype = {

  assemble: function() {

    ...

  },

  wash: function() {

    ...

  },

  ride: function() {

    ...

  },

  repair: function() {

    ...

  }

};





/* Usage. */



var californiaCruisers = new BicycleShop();

var yourNewBike = californiaCruisers.sellBicycle('The Speedster');







/* BicycleFactory namespace. */



var BicycleFactory = {

  createBicycle: function(model) {

    var bicycle;

    

    switch(model) {

      case 'The Speedster':

        bicycle = new Speedster();

        break;

      case 'The Lowrider':

        bicycle = new Lowrider();

        break;

      case 'The Comfort Cruiser':

      default:

        bicycle = new ComfortCruiser();

    }

    

    Interface.ensureImplements(bicycle, Bicycle);

    return bicycle;

  }

};



/* BicycleShop class, improved. */



var BicycleShop = function() {};

BicycleShop.prototype = {

  sellBicycle: function(model) {

    var bicycle = BicycleFactory.createBicycle(model);

    

    bicycle.assemble();

    bicycle.wash();

    

    return bicycle;

  }

};



/* BicycleFactory namespace, with more models. */



var BicycleFactory = {

  createBicycle: function(model) {

    var bicycle;

    

    switch(model) {

      case 'The Speedster':

        bicycle = new Speedster();

        break;

      case 'The Lowrider':

        bicycle = new Lowrider();

        break;

      case 'The Flatlander':

        bicycle = new Flatlander();

        break;

      case 'The Comfort Cruiser':

      default:

        bicycle = new ComfortCruiser();

    }

    

    Interface.ensureImplements(bicycle, Bicycle);

    return bicycle;

  }

};

2.工厂模式

/* BicycleShop class (abstract). */



var BicycleShop = function() {};

BicycleShop.prototype = {

  sellBicycle: function(model) {

    var bicycle = this.createBicycle(model);

    

    bicycle.assemble();

    bicycle.wash();

    

    return bicycle;

  },

  createBicycle: function(model) {

    throw new Error('Unsupported operation on an abstract class.');

  }

};



/* AcmeBicycleShop class. */



var AcmeBicycleShop = function() {};

extend(AcmeBicycleShop, BicycleShop);

AcmeBicycleShop.prototype.createBicycle = function(model) {

  var bicycle;



  switch(model) {

    case 'The Speedster':

      bicycle = new AcmeSpeedster();

      break;

    case 'The Lowrider':

      bicycle = new AcmeLowrider();

      break;

    case 'The Flatlander':

      bicycle = new AcmeFlatlander();

      break;

    case 'The Comfort Cruiser':

    default:

      bicycle = new AcmeComfortCruiser();

  }



  Interface.ensureImplements(bicycle, Bicycle);

  return bicycle;  

};



/* GeneralProductsBicycleShop class. */



var GeneralProductsBicycleShop = function() {};

extend(GeneralProductsBicycleShop, BicycleShop);

GeneralProductsBicycleShop.prototype.createBicycle = function(model) {

  var bicycle;



  switch(model) {

    case 'The Speedster':

      bicycle = new GeneralProductsSpeedster();

      break;

    case 'The Lowrider':

      bicycle = new GeneralProductsLowrider();

      break;

    case 'The Flatlander':

      bicycle = new GeneralProductsFlatlander();

      break;

    case 'The Comfort Cruiser':

    default:

      bicycle = new GeneralProductsComfortCruiser();

  }



  Interface.ensureImplements(bicycle, Bicycle);

  return bicycle;

};





/* Usage. */



var alecsCruisers = new AcmeBicycleShop();

var yourNewBike = alecsCruisers.sellBicycle('The Lowrider');



var bobsCruisers = new GeneralProductsBicycleShop();

var yourSecondNewBike = bobsCruisers.sellBicycle('The Lowrider');