Comments on Mark A. Ziesemer: Respecting the JavaScript global namespace

Hi Mark, I do have a concern with global namespac...

2010-09-07T08:37:57.754-05:00

Hi Mark,

I do have a concern with global namespace and javascript modules.
I'm using your rules for my add-on, but now I want to isolate part of my code in a javascript module.

So I have all my javascript code wrapped into the following object for extension QuickFileMail :
if(!net) var net={};
if(!net.phpconcept) net.phpconcept={};
if(!

Nick: You're completely correct - using the &...

2010-09-02T21:51:22.823-05:00

Nick: You're completely correct - using the "let" statement introduced with JavaScript 1.7 is a great alternative. This should work great for use within Firefox extensions, but for use within web pages, the only web browser currently supporting JavaScript 1.7 is also Mozilla Firefox.

However, the object namespacing approach still serves a purpose, even when "let&

Ste / gigamorph: Regarding the "JavaPackage&...

2010-09-02T21:42:09.211-05:00

Ste / gigamorph:

Regarding the "JavaPackage" issues under Mozilla Rhino, please refer to https://bugzilla.mozilla.org/show_bug.cgi?id=468385.

As a quick work-around, one can just evaluate "delete" statements during the Rhino initialization to remove these object references,

Doesn't using 'let' rather than 'v...

2010-07-20T05:24:29.059-05:00

Doesn't using 'let' rather than 'var' in Javascript 1.7 within extensions avoid polluting the global namespace in an easier manner? see: https://developer.mozilla.org/en/new_in_javascript_1.7

Ste: I have the same problem. The problem seems t...

2010-04-21T13:45:29.243-05:00

Ste: I have the same problem.

The problem seems to be Rhino pre-defines java, com, org, net, and edu as Java packages and assumes any reference relative to them to be also a Java Package.

Thus com, com.ziesemer, com.ziesemer.myPackage all evaluate as JavaPackage instead of undefined so none of the first three lines get effectively executed.

It should work if you

Hi Mark, great article! I wonder if it is still va...

2010-03-20T09:58:10.411-05:00

Hi Mark, great article! I wonder if it is still valid with ECMAScript 1.6 implemention "Mozilla Rhino" 1.6 release 2.
I cut and pasted the updated sample and I get the following error running it inside jrunscript:

[ste ~] o(= jrunscript /tmp/test.js
script error in file /tmp/test.js : sun.org.mozilla.javascript.EcmaError: TypeError: Cannot call property alertHello

Vikram - the code you posted by itself is valid, t...

2010-02-20T09:16:16.443-06:00

Vikram - the code you posted by itself is valid, though I assume that you would replace "namespace" with something more unique.

See my response to Rez, just above your comment, as it looks like you two are having the exact same issue.

Ravi: com.ziesemer.myfun(); Will work from anywher...

2010-02-20T09:13:13.003-06:00

Ravi: com.ziesemer.myfun(); Will work from anywhere, including from within any other function.

if(!com) var com={}; if(!com.ziesemer) com.zieseme...

2010-02-20T02:20:55.798-06:00

if(!com) var com={};
if(!com.ziesemer) com.ziesemer={};

com.ziesemer.myPackage = function(){
var pub = {};

pub.name = "visitor";
pub.greeting = "hello " + pub.name;
pub.alertHello = function(){
alert(pub.greeting);
};
return pub;
}();

com.ziesemer.myfun = function()
{
var tst

hello everyone !! I'm like a beginner in jav...

2009-12-30T06:42:49.193-06:00

hello everyone !!

I'm like a beginner in java Script and restructuring one of my Firefox addon for global Namespacing.

------------------
var namespace = new function() {
return {
i: 0,
var: 'bar',

function1: function(){
alert("inside function 1");
namespace.function2();

Rez - it's difficult to provide a complete ans...

2009-07-28T12:34:51.954-05:00

Rez - it's difficult to provide a complete answer without being able to view the complete extension, but it sounds like you're working with 2 separate scopes (possibly different windows or frames), or that your .js file is not being loaded. If you use the steps and debugging tools listed at https://

Hey Mark, Thanks for the article! I am currentl...

2009-07-15T23:22:58.782-05:00

Hey Mark,

Thanks for the article!

I am currently re-writing an extension of mine to have it moved from the sandbox. I had a couple of functions in my JS file doing certain tasks and now I tried doing the following:

if(!com) var com={};
if(!com.hottypo) com.hottypo={};
if(!com.hottypo.myPackage) com.hottypo.myPackage={};

com.hottypo.myPackage

Jaap - have you tried removing "this.", ...

2009-06-28T12:44:04.370-05:00

Jaap - have you tried removing "this.", and just referencing "_member_variable"?

If there is a naming-conflict with another variable in a function closer in the scope chain, you could access the inner variable as fully-qualified, e.g. org.mozdev.dictionarysearch._member_variable.

I'd also recommend writing the object as a function with a closure,

Hi, I got an email from mozilla addons that I nee...

2009-06-28T12:09:37.829-05:00

Hi,

I got an email from mozilla addons that I need to wrap my variables and functions in the way you suggest. However it does not seem to work because the "this" variable is not pointing to the object I defined but to a chrome window. See the example below

What should I do to correct this?

function debug (str) {
consoleService =

I wrote an article regarding the importance of namespacing in JavaScript.

Thanks, Mark. I believe I understand now. We can ...

2009-04-16T11:53:00.000-05:00

Thanks, Mark. I believe I understand now. We can set up the base of the namespace in file1 and then extend the namespace in file2 or even add more functions to the original namespace. I like this method. Great job. Thanks for your assistance.

Vinny2020 - First, we should use something like my...

2009-04-16T10:43:00.000-05:00

Vinny2020 - First, we should use something like my JavaScript namespace function to declare the namespaces so that each level is only added when necessary, without overwriting anything.

Using this, assume in the first file:

"com.example".namespace().a = function(){...};
"com.example&

Mark, yes that will work, but in the additional ja...

2009-04-16T09:56:00.000-05:00

Mark, yes that will work, but in the additional javascript files how would I define the function? Would I have to use the whole package name? If I redefine the initial "package" function in file 2, that will blow away anything created in file 1. So after the initial definition in file 1, do I then use the full "namespace" to define functions in file 2"?

Using your example, in file 2

Vinny2020 - it really doesn't matter. Whether...

2009-04-15T18:49:00.000-05:00

Vinny2020 - it really doesn't matter. Whether it is a "sub-domain" or a function within a "domain", they are both accessed through the same dot-notation. So you could start out by declaring one "package" with various sub-packages and functions in your first source file. In each additional source file, you could add additional sub-packages and/or functions.

I like this technique. However I am wondering, ho...

2009-04-15T13:48:00.000-05:00

I like this technique. However I am wondering, how would you use your method to encapsulate 3 javascript source files, but still have them as the same "package"?

I'm sure I could do it by adding another "sub domain" to the dot-notation, but what if I want them all to have the same "domain"?

Anonymous - I guess that is why I didn't recommend...

2009-03-27T08:24:00.000-05:00

Anonymous - I guess that is why I didn't recommend it. I'm removing it from the post as it is incorrect.

The code you provided:

if(!com) var com={};...

2009-03-26T22:26:00.000-05:00

The code you provided:

if(!com) var com={};
if(!com.ziesemer) com.ziesemer={};
if(!com.ziesemer.myPackage) com.ziesemer.myPackage={};

with(com.ziesemer.myPackage){
name = "visitor";
greeting = "hello " + name;
alertHello = function(){
alert(greeting);
}
}

com.ziesemer.myPackage.alertHello();

throws an error when

Ryan - I don't know, especially without seeing...

2009-01-24T15:04:00.000-06:00

Ryan - I don't know, especially without seeing more details. Just check for typos, etc. The code is definitely correct.

Claudijo - I'd have to say that this and the extensions windows are two different issues. The main goal behind this post is simply managing the namespace of a given scope. Your issue with the different extension windows is working across different scopes.

Thanks for a good reference.

As a novice j...

2009-01-24T12:24:00.000-06:00

Thanks for a good reference.

As a novice javascript programmer and extension developer I have a question. How is the problem with loose variables exploited (or even used as a positive side effect)?

As far as I know, It is not sufficient to make a variabel global in the overlay file in order to access it from a javascript loaded in the firefox sidebar (instead I have to do

Hi Mark,

I am using the code you recommende...

2009-01-23T20:34:00.000-06:00

Hi Mark,

I am using the code you recommended for Firefox extension, as below:

if(!com) var com={};
if(!com.ziesemer) com.ziesemer={};
com.ziesemer.myPackage = function(){};

and I include this .js file in the main XUL file, and then it generates an error in the error console:
invalid assignment left-hand side:
com.ziesemer.myPackage = function(){};
<