javascript命名空间的首选技术 [英] Preferred technique for javascript namespacing

问题描述

如果我不开始使用某种命名空间技术，我的代码将变成一团糟。我对编写大型javascript项目相对较新，但在C ++ / java / python等系统编程方面具有丰富的经验。

My code is going to turn into a mess if I don't start using some sort of namespacing technique. I'm relatively new to programming large javascript projects but have significant experience with systems programming in C++/java/python etc.

基本上我正在尝试识别哪个是创建javascript命名空间的首选方法，以及每种方法的优缺点。

Basically I'm trying to identify which is the preferred method for creating javascript namespaces, and what the pros/cons are for each method.

例如，我可以使用以下三种方法之一：

For example I could use either of the following three methods:

var proj.lib.layout = {
  "centreElem":     
  function (elem, W, H){

  },

  "getAbsolutePosition":
  function (elem){

  }
};

OR

var proj.lib.layout = {};
(function(){
  var l = proj.lib.layout;

  l.centreElem = function (elem, winW, winH){
    ..
  }

  l.getAbsolutePosition = function (elem){
    ..
  }
})();

OR

var proj.lib.layout = new function(){
  function centreElem(elem, W, H){
    ..
  }

  function getAbsolutePosition(elem){
    ..
  }

  this.centreElem          = centreElem;
  this.getAbsolutePosition = getAbsolutePosition;
} ();

还有其他方法可以做得太明显，但这些是我见过的第一个想到。任何人都可以说有一种最好的技术，或者至少指向一些利弊，我可以从中评估哪种方式最适合我？

There are other ways to do it too obviously, but these were the first that I've seen and thought of. Can anyone say there is a "best" technique, or at least point me towards some pros/cons from which I can evaluate which is best for me?

推荐答案

请注意，您必须先创建所有中间对象，然后才能分配到这样的子对象：

Note that you have to create all the intermediary objects before you can assign to a sub-object like that:

window.one.two.three = {}; // fails
window.one = { two: { three: {} } };

考虑编写命名空间方法，以便统一命名空间代码。例如：

Consider writing a namespacing method, so you can unify your namespace code. For example:

window.proj = {};
// n - {String} - A string representing a namespace to create on proj
// returns an object you can assign values to
window.proj.namespace = function(n) { /* ... */ };

(function(NS) {
    NS.myMethod = function() {};
    NS.myOtherMethod = function() {};
    NS.myProperty = "FOO";
})(proj.namespace('lib.layout'));

assert(proj.lib.layout.myProperty === "FOO");

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