JavaScript之工厂模式

JavaScript之工厂模式

/***************外js*********************/
//接口类，用来创建接口 
    var Interface = function (name) {
        if (arguments.length != 2) {
            throw new Error("创建的接口不符合标准，必须有两个参数，第二个参数是接口的方法");
        }
        this.name = name;
        this.methods = [];
        var methods = arguments[1];
        for (var i = 0; i < methods.length; i++) {
            this.methods.push(methods[i]);
        }
    }
    Interface.ensureImplements = function (obj) {
        if (arguments.length < 2) {
            throw new Error("要检查的接口必须传入接口对象的参数，所以参数的个数必须大于等于2")
        }
        for (var i = 1; i < arguments.length; i++) {
            var intObj = arguments[i];
            if (intObj.constructor != Interface) throw new Error(intObj + "接口的对象不正确");
            //检查方法是否符合要求
            var cmethods = intObj.methods;
            for (var j = 0; j < cmethods.length; j++) {
                if (!obj[cmethods[j]] || typeof obj[cmethods[j]] != "function") throw new Error("必须实现：" + cmethods[j] + "这个方法");
            }
        }

    };


var ICar=new Interface("ICar",["assemble","wash","run"]);

var Car = function(){};
Car.prototype ={
    assemble:function(){
        alert("小车组装中");
    },
    wash:function(){
        alert("小车清洗中");
    },
    run:function(){
        alert("嘟嘟中");
    }
}

var Truck = function(){};
Truck.prototype ={
    assemble:function(){
        alert("大卡车组装中");
    },
    wash:function(){
        alert("大卡清洗中");
    },
    run:function(){
        alert("轰隆隆");
    }
}

var HongYong = {};
HongYong.CarFactory = {
    createCar:function(model){
        var car;
        switch(model){
            case "car":
                car =new Car();
            break;
            case "truck":
                car =new Truck();
            break;
        }
        Interface.ensureImplements(car,ICar);
        return car;
    }
};


var CarShop = function(){};
CarShop.prototype = {
    sellCar:function(model){
        var car =HongYong.CarFactory.createCar(model);
        car.assemble();
        car.wash();
        return car;
    }
};
var c=new CarShop().sellCar("truck");
c.run();