/* interface FlyBehavior - abstract Strategy of FlyBehavior */
var FlyBehavior = function () {
this.fly = function () {};
};
/* FlyWithWings - concrete Strategy of FlyBehavior */
var FlyWithWings = function () {
this.fly = function () {
console.log("I`m flying");
};
};
FlyWithWings.prototype = new FlyBehavior();
FlyWithWings.prototype.constructor = FlyWithWings;
/* FlyNoWay - concrete Strategy of FlyBehavior */
var FlyNoWay = function () {
this.fly = function () {
console.log("I can`t fly");
}
};
FlyNoWay.prototype = new FlyBehavior();
FlyNoWay.prototype.constructor = FlyNoWay;
/* FlyRocketPowered - concrete Strategy of FlyBehavior */
var FlyRocketPowered = function () {
this.fly = function () {
console.log("I`m flying with a rocket");
};
};
FlyRocketPowered.prototype = new FlyBehavior();
FlyRocketPowered.prototype.constructor = FlyRocketPowered;
/* interface QuackBehavior - abstract Strategy of QuackBehavior */
var QuackBehavior = function () {
this.quack = function () {};
};
/* Quack - concrete Strategy of QuackBehavior */
var Quack = function () {
this.quack = function () {
console.log("Quack");
}
};
Quack.prototype = new QuackBehavior();
Quack.prototype.constructor = Quack;
/* Squeak - concrete Strategy of QuackBehavior */
var Squeak = function () {
this.quack = function () {
console.log("Squeak");
}
};
Squeak.prototype = new QuackBehavior();
Squeak.prototype.constructor = Squeak;
/* MuteQuack - concrete Strategy of QuackBehavior */
var MuteQuack = function () {
this.quack = function () {
console.log("<< Silence >>");
}
};
MuteQuack.prototype = new QuackBehavior();
MuteQuack.prototype.constructor = MuteQuack;
/* Abstract Client of abstract FlyBehavior Strategy and abstract QuackBehavior Strategy */
var Duck = function () {
var flyBehavior;
var quackBehavior;
// abstract method
this.display = function () {};
this.setFlyBehavior = function (fb) {
flyBehavior = fb;
};
this.setQuackBehavior = function (qb) {
quackBehavior = qb;
};
this.performFly = function () {
flyBehavior.fly();
};
this.performQuack = function () {
quackBehavior.quack();
};
this.swim = function () {
console.log("All ducks float, even decoys!");
};
};
/* Concrete Client of FlyWithWings Strategy and Quack Strategy */
var MallardDuck = function () {
this.setFlyBehavior(new FlyWithWings());
this.setQuackBehavior(new Quack());
this.display = function () {
console.log("I`m a real Mallard duck");
};
};
MallardDuck.prototype = new Duck();
MallardDuck.prototype.constructor = MallardDuck;
/* Concrete Client of FlyNoWay Strategy and Quack Strategy */
var ModelDuck = function () {
this.setFlyBehavior(new FlyNoWay());
this.setQuackBehavior(new Quack());
this.display = function () {
console.log("I`m a model duck");
};
};
ModelDuck.prototype = new Duck();
ModelDuck.prototype.constructor = ModelDuck;
/* test application */
var Application = function () {
this.run = function () {
var mallard = new MallardDuck();
mallard.performQuack();
mallard.performFly();
var model = new ModelDuck();
model.performQuack();
model.performFly();
// dynamic set new Concrete Strategy FlyRocketPowered
model.setFlyBehavior(new FlyRocketPowered());
model.performFly();
};
};
var application = new Application();
application.run();
На выходе получаем следующие сообщения клиентов
Quack
I`m flying
Quack
I can`t fly
I`m flying with a rocket
Ниже представлена схема реализации паттерна Стратегия (Strategy)
