如何将方法设为私有并在 Coffeescript 中继承?

问题描述

如何将btnClick"方法设为私有?

How to make method "btnClick" private?

class FirstClass
  constructor: ->
    $('.btn').click @btnClick

  btnClick: =>
    alert('Hi from the first class!')

class SecondClass extends FirstClass
  btnClick: =>
    super()
    alert('Hi from the second class!')

@obj = new SecondClass

http://jsfiddle.net/R646x/17/

推荐答案

JavaScript 中没有私有，所以 CoffeeScript 中也没有私有.您可以像这样在班级级别将内容设为私有:

There's no private in JavaScript so there's no private in CoffeeScript, sort of. You can make things private at the class level like this:

class C
    private_function = -> console.log('pancakes')

private_function 将只在 C 中可见.问题是 private_function 只是一个函数，它不是 C 实例的方法.您可以使用 Function.apply 解决这个问题 或 Function.call:

That private_function will only be visible within C. The problem is that private_function is just a function, it isn't a method on instances of C. You can work around that by using Function.apply or Function.call:

class C
    private_function = -> console.log('pancakes')
    m: ->
        private_function.call(@)

所以在你的情况下，你可以这样做:

So in your case, you could do something like this:

class FirstClass
    btnClick = -> console.log('FirstClass: ', @)
    constructor: ->
        $('.btn').click => btnClick.call(@)

class SecondClass extends FirstClass
    btnClick = -> console.log('SecondClass: ', @)

演示:http://jsfiddle.net/ambiguous/5v3sH/

或者，如果您不需要 btnClick 中的 @ 是任何特别的东西，您可以按原样使用该函数:

Or, if you don't need @ in btnClick to be anything in particular, you can just use the function as-is:

class FirstClass
    btnClick = -> console.log('FirstClass')
    constructor: ->
        $('.btn').click btnClick

演示:http://jsfiddle.net/ambiguous/zGU7H/

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