JS設計模式--Factory(工廠)模式
摘要：
工廠模式
提供一個通用的介面來建立物件
示例
//Car建構函式
function Car(option) {
this.doors = option.doors || 4
this.color = option.color || 'red'
...
工廠模式
提供一個通用的介面來建立物件
示例
//Car建構函式
function Car(option) {
this.doors = option.doors || 4
this.color = option.color || 'red'
this.state = option.state || 'brand new'
}
//Truck建構函式
function Truck(option) {
this.color = option.color || 'blue'
this.wheelSize = option.wheelSize || 'large'
this.state = option.state || 'used'
}
//Vehicle工廠
function VehicleFactory() {}
VehicleFactory.prototype.vehicleClass = Car
VehicleFactory.prototype.createVehicle = function(option) {
if(option.vehicleType == 'car') {
this.vehicleClass = Car
}else {
this.vehicleClass = Truck
}
return new this.vehicleClass(option)
}
//建立生成汽車的工廠例項
var carFactory = new VehicleFactory()
var car = carFactory.createVehicle({
vehicleType: 'car',
color: 'yellow',
doors: 6
})
console.log(car instanceof Car)
console.log(car)
//true
//Car {doors: 6, color: "yellow", state: "brand new"}
var movingTruck = carFactory.createVehicle({
vehicleType: 'truck',
color: 'red',
state: 'like new',
wheelSize: 'small'
})
console.log(movingTruck instanceof Truck)
console.log(movingTruck)
//true
//Truck {color: "red", state: "like new", wheelSize: "small"}
適用場景
- 當物件或組建設定涉及高複雜性時
- 當需要根據所在當不同環境輕鬆生成物件當不同例項時
- 當處理很多共享相同屬性當小型物件或元件時
- 在編寫只需要滿足一個API契約（亦稱鴨子型別）的其他物件的例項物件時。對解耦是很有用對。