Question

我正试图做一个简单的事手。

(说明,我不想试图实施完全模糊的出版/登记模式;我只想为什么我的例子不像我认为应该那样工作)

var myObj = (function () {

  var private = "X";

  function triggerEvent(eventName) {
    if (this[eventName]) {
      this[eventName]();
    }
  }

  // Setter / Getter
  function getProp() {
    return private;
  }

  function setProp(value) {
    private = value;
    triggerEvent("onPropChange");
  }

  // Public API
  return {
    // Events
    "onPropChange": null,    // Fires when prop value is changed

    // Methods
    "getProp": getProp,
    "setProp": setProp
  };
})();

// Now set event handler
myObj.onPropChange = function () {
  alert("You changed the property!");
};

myObj.setProp("Z");  // --> Nothing happens. Wrong
                     // Why doesn t my alert show?

我把我的物体的<代码>onPropChange财产设定为更简单的手稿功能,但并未发射。我已对此做了改动,似乎在<条码>上。。我认为,它应当参考<代码>myObj(这是我所需要的)。

谁能解释我的想法中的错误,我如何纠正? 帮助非常受赞赏。

j 此处为

Answer 1

修改你的法典,使你产生肥胖症,然后返回:

var myObj = (function () {

  var private = "X";
  var obj = {
    "onPropChange": null,    // Fires when prop value is changed

    // Methods
    "getProp": getProp,
    "setProp": setProp
  };

  function triggerEvent(eventName) {
    if (obj[eventName]) {
      obj[eventName]();
    }
  }

  // Setter / Getter
  function getProp() {
    return private;
  }

  function setProp(value) {
    private = value;
    triggerEvent("onPropChange");
  }

  return obj;          
})();

This way you have a reference to the object for the private functions.

固定单项——

Another way to fix it that you might prefer is to use the .call function:

function setProp(value) {
    private = value;
    triggerEvent.call(this, "onPropChange");
}

This specifies what this will be in the method being called (triggerEvent).

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