Javascript 将JS设计模式转换为CoffeScript时发生类错误

在俄罗斯维基百科上，我找到了

Builder

设计模式的代码，并尝试将其转换为咖啡脚本

这就是本文的要点

我将构造函数（new FuncName）调用的每个函数都更改为

class FuncName

，但是

PizzaBuilder.call（this）出现错误在构造函数中

PizzaBuilder = ->
    pizza = new Pizza()
    @getPizza = -> pizza
    @createNewPizzaProduct = -> pizza.clear()
    @buildDough = (val) ->
    @buildSauce = (val) ->
    @buildTopping = (val) ->

class HawaiianPizzaBuilder
    PizzaBuilder.call this
    pizza = @getPizza() # imitation protected
    buildDough: -> pizza.setDough "cross"
    buildSauce: -> pizza.setSauce "mild"
    buildTopping: -> pizza.setTopping "ham+pineapple"

在javascript函数中，HawaiianPizzaBuilder

是类的构造函数。在Coffeescript中，您需要将其显式定义为

构造函数

方法，如下所示：

class HawaiianPizzaBuilder
    constructor: ->
       PizzaBuilder.call this
       pizza = @getPizza() # imitation protected
       @buildDough: -> pizza.setDough "cross"
       @buildSauce: -> pizza.setSauce "mild"
       @buildTopping: -> pizza.setTopping "ham+pineapple"

您还忘记了

这个。

在

构建…

函数定义之前

不过，我想推荐另一个版本的相同模式示例，因为coffeescript提供了更简单的类继承语法，如下所示：

class PizzaBuilder
    constructor: ->
        @pizza = new Pizza()
    buildDough: -> @
    buildSauce: -> @
    buildTopping: -> @

class HawaiianPizzaBuilder
    buildDough: -> 
        @pizze.setDough "cross"
        @
    #...override other methods


 builder = new HawaiianPizzaBuilder
 myPizza = builder.buildDough().buildSauce().pizza

class PizzaBuilder
    constructor: ->
        @pizza = new Pizza()
    buildDough: -> @
    buildSauce: -> @
    buildTopping: -> @

class HawaiianPizzaBuilder
    buildDough: -> 
        @pizze.setDough "cross"
        @
    #...override other methods


 builder = new HawaiianPizzaBuilder
 myPizza = builder.buildDough().buildSauce().pizza