如何在不访问包含作用域的内容的情况下安全地访问Javascript模块模式中的其他同级函数和变量?

问题描述

我在模块模式之后构造了一个Javascript对象.我有几个私有函数，它们是从其他同级私有"函数中调用的.我该如何访问另一个变量/函数而又不会意外访问全局/外部变量/对象/函数?

I have a Javascript Object structured after the Module Pattern. I have several private function in it which are called from other sibling "private" functions. How can I access another variable/function without the potential to accidentally access a global/external variable/object/function?

function doSomething() {
  alert("Something I don't want to do");
}

var My.Namespaced.SingletonClass = (function() {
  var init = function() {
    doSomething();
  }

  var doSomething = function() {
    alert("Something I want to do");
  }

  return {
    "init": init;
  }
})();

My.Namespaced.SingletonClass.init();

我的猜测是，上面的代码实际上将访问正确的内部doSomething函数，但是我想要的是更多的安全性.我该如何显式地解决内部/嵌套函数，而不必担心意外调用函数或解决我的单例范围内的对象?

My guess is that the above code would in fact access the correct, inner doSomething function, but I'd like some more security than that. How can I explicitly address the inner/nested function without fear of accidentally calling functions or addressing objects in the scope around my singleton?

推荐答案

简短版本:您不能.如果未将doSomething定义为init的同级，则JavaScript会依次搜索范围更广的范围，直到找到doSomething函数，否则它将用尽搜索范围.

Short version: you can't. If doSomething isn't defined as a sibling of init, then JavaScript will search successively broader scopes until it finds a doSomething function, or it runs out of scopes to search.

长版本:您可以通过使用私有对象来保存您的私有助手功能来防止这种行为，如下所示:

Longer version: you can prevent this sort of behavior by using a private object to hold your private helper functions, like this:

function doSomething() {
  alert("Something I don't want to do");
}

// Assuming My.Namespaced is already defined:
My.Namespaced.SingletonClass = (function() {
  var helpers = {};

  helpers.doSomething = function() {
    alert("Something I want to do");
  }

  var init = function() {
    helpers.doSomething();
  }

  return {
    init: init
  }
})();

My.Namespaced.SingletonClass.init();

我不确定助手功能是真正的兄弟姐妹是否重要(但是我不明白为什么这特别重要).

I'm not sure if it's important that the helper functions are truly siblings (but I don't see why that would particularly matter).

还请记住，在使用SingletonClass之前，必须先定义My和My.Namespaced-并且无需为返回的对象中的键使用JSON样式的引号.

Also keep in mind that My and My.Namespaced need to be defined before you tack on SingletonClass - and there's no need to use JSON-style quoting for keys in the object you're returning.

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