How can I access a newly-opened tab's window object? [in a firefox extension]

Question

I'm attempting to convert a Greasemonky script to an extension for Firefox and I'm trying to make my extension automatically attach a simple script to any webpage when a new tab is opened. I'm converting the script from Greasemonkey because I'd like to take advantage of advanced preferences and menu options.

I access the tab using this:

var container = gBrowser.tabContainer;
container.addEventListener("TabOpen", tabAdded, false);

function tabAdded(event) {
var newtabwindow = event.target.____ //I don't know what goes here
//attach script to newtabwindow
}

and my goal is to append the script to the document in the new tab once it loads using this function:

function scriptrunner(targetwindow) {
var myScript = targetwindow.content.document.createElement('script');
    myScript.type = 'text/javascript';
    myScript.setAttribute('src','chrome://addonname/content/addonscript.js');
    targetwindow.content.document.getElementsByTagName('head')[0].appendChild(myScript);
}

This function works fine to attach the script to the current page when attached to a toolbar button with oncommand="scriptrunner(window)", but I don't know how I could access the window in the newly opened tab, or if I should cut out the window from the equation and access the document another way.

Answer 1

You are looking for contentWindow, which is a property of the browser element.

Given a tab, call gBrowser.getBrowserForTab to acquire the browser element associated with the tab. Then access either contentDocument or contentWindow property of the browser element (these are equivalent to the document and window objects you should already be familiar with).

Also -- if I'm not mistaken -- you'll need to listen for the "load" event of the contentWindow in addition to listening to events for the tab.