Best way to get location from inside a extension

top.location.href, definitely (at least if you are trying to do it from the document loaded - this wasn't quite clear from you post). If you want documentation - find JavaScript 1.3 Reference (this version still has some info on window and document objects unlike JS 1.5).

window.location - the string representation of the Location object matches the href property but you shouldn't rely on this
document.location - this is only for compatibility, I think this was a IE-only feature originally
document.URL - JS 1.3 Reference explains how this differs from window.location.href. Usually you shouldn't need this.
window.top
getBrowser(), content etc - rrrright, why simple if you can do it complicated

Comment by Wladimir Palant at September 27, 2005 07:51 PM | Permalink

Yes, and if you are doing it from some script running outside the document loaded, then you probably need getBrowser().contentWindow.location.href.

Comment by Wladimir Palant at September 27, 2005 07:56 PM | Permalink

"... in both the current Mozilla SeaMonkey and Mozilla Firefox."

I thought that SeaMonkey is no longer a part of Mozilla, as in it is now being developed independently of Mozillian trendy ideas? (Apart from the Mozilla Foundation providing infrastructure resources "only.")

Signed,
'Confused'

Do you want the exact URL of the page, the URL as displayed in the adddress bar (without wyciwyg), or the URL that sorta corresponds to the document's principal (without jar, javascript, data, wyciwyg)? This depends on what you're going to do with the URL.

Also, are you sure you want a URL string instead of an nsIURI object?

Comment by Jesse Ruderman at September 27, 2005 09:41 PM | Permalink

gBrowser().mCurrentBrowser.currentURI.spec

should be

gBrowser.mCurrentBrowser.currentURI.spec

Comment by LouCypher at September 27, 2005 09:50 PM | Permalink

Laurance: You are correct. But how exactly is that relevant to Henrik's extensions?

Comment by Jon Henry at September 27, 2005 10:36 PM | Permalink

guys, what's wrong with:
getBrowser().currentURI.spec?

seems easier than either of:
>gBrowser.mCurrentBrowser.currentURI.spec
and
>getBrowser().contentWindow.location.href.

Also, you should generally prefer URI objects to URI strings...

(as for your blog posting, "window" and "document" refer to the chrome window, so they are usually a chrome:// url. if you want the url loaded in the browser, you'd need content.* / content.document.*)

Generally, properties that start with "m" followed by a camelcased word or phrase are intended to be private variables, so you're setting yourself up to be broken at some point if you use |getBrowser().mCurrentBrowser| and friends; there are public interfaces which do the trick just as well and are less likely to be broken.

Another point to mention is that (to the best of my knowledge) a tabbrowser is supposed to have attributes and properties which are a superset of those of a browser, meaning that if you use browser properties on a tabbrowser you'll get the same results for the currently viewed URL in a browser. This is so that you don't need to know anything about tabbrowsers if your code doesn't explicitly interact with them.

Comment by Jeff Walden at September 28, 2005 05:28 AM | Permalink

I think what you should *officially* use is

window.content.location.href

This is what Firefox uses it's it's browser code for sending a URL via e-mail. This also assumes you want what is found in the location bar.

(see: http://lxr.mozilla.org/mozilla1.8/source/browser/base/content/browser.js#5603 )

I used to use:
Components.lookupMethod(window._content, 'location').call(window._content).href

As it's was the 'safe way' to do it as I think it was an older form of XPWrappers.

Comment by jed at September 28, 2005 05:34 AM | Permalink

Well, hello everyone.
It looks like this page talks about what I'm looking for! Maybe you guys can give me a big help.
I've place an extension in my Internet Explorer tool bar, which has to replace the current URL, depending on the situation...
for example: if the user is in URL1, then by clicking the button, the browser should redirect to URL2. If the user is in URL2, then he should go to URL1. So, when the user click the button, it will call a .js file, which will find out where the user is, then change the URL. The problem is, when the .js file is called, it can't get the current URL. I've made a test, with alert(window.location.href), but it shows the physical path of the file in my PC (like file:///C:/...) So, all I want now is to be able to find out where the user is, from an Internet Explorer extension. I've tried everything, like window.referrer, window.location, this.window.location, but nothing. Any ideas?

Thanks everyone.

how to use this in firefox

Um, Bob, maybe this is noobish but how exactly do you make an Internet Explorer extension?

IE calls it a Browser Helper Object (all native), which is more complex (C++) than an extension written in a high level language.