Comments on: An Easy Way to Implement Namespaces in JavaScript

By: Timothy Stone

Timothy Stone — Fri, 31 Jul 2009 16:41:26 +0000

Hmmm… concerned about that use of `eval’ … you might want to consider refactoring it. Take a look at the YAHOO object itself for an example with leveraging `eval’.

By: Alex Melman

Alex Melman — Thu, 07 Aug 2008 17:11:00 +0000

Thanks for the comments. To Mazharkhan, I actually do have an example of how to use the function, but I realize that I sort of buried it in the middle. Basically, you use the function as such:
createNamespace(“arc90.components”);
This creates the namespace, so now you can define functions and classes such as:
arc90.components.CheckBox = {};
The advantage of using the function is that if you don’t, you will have to define each level of the namespace separately, like this:
var arc90 = {};
var arc90.components = {};
In addition, you would have to check to see if those objects already exist. Otherwise you will overwrite them with blank objects, which is not what you want to do when defining a namespace.
As for the first comment, I promise to address it soon.

By: Mazharkhan

Mazharkhan — Thu, 07 Aug 2008 16:56:43 +0000

I got something and something not.
you give only 50% guidance. if you put one example with every blog.

By: Josh W

Josh W — Thu, 03 Jul 2008 02:43:41 +0000

// Let’s try that “for” again.
function createNamespace(ns)
{
// First split the namespace string separating each level of the namespace object.
var splitNs = ns.split(“.”);
// Define a string, which will hold the name of the object we are currently working with. Initialize to the first part.
var builtNs = splitNs[0];
var i, base = window;
for (i = 0; i < splitNs.length; i++)
{
if (typeof(base[ splitNs[i] ]) == “undefined”) base[ splitNs[i] ] = {};
base = base[ splitNs[i] ];
}
return base; // Return the namespace as an object.
}

By: Josh W

Josh W — Thu, 03 Jul 2008 02:36:23 +0000

You have a typo:
for (i = 0, i 0) ? (“.” + splitNs[i]) : “”;
// Check if the object we want to add exists, and add a new empty object if it doesnt.
eval(builtNs + ” = typeof(” + builtNs + “) ==’undefined’ ? {} : ” + builtNs + “; “);
}
return eval(ns); // Return the namespace as an object.
}
You also might be able to use “window” instead of “eval”, as eval can but unsafe.
function createNamespace(ns)
{
// First split the namespace string separating each level of the namespace object.
var splitNs = ns.split(“.”);
// Define a string, which will hold the name of the object we are currently working with. Initialize to the first part to the current window.
var i, base = window;
for (i = 0; i