Access dom after "chrome-document-global-created"

Question

I need to get the DOM when the Mozilla observer event "chrome-document-global-created" is fired. Therefore, I have the following code. But how can I get the DOM from there? Data is null (according to documentation), can someone please tell me which object i have to use?

Many thanks!

observe: function(subject, topic, data) {
  which object is it? document? window? cant find anything there about dom...
}

Answer 1

If you look at the documentation, subject is a window. You still need to use QueryInterface() to actually get the nsIDOMWindow interface but after that things get pretty obvious:

var doc = subject.QueryInterface(Components.interfaces.nsIDOMWindow).document;
dump(doc.documentElement.innerHTML);

Note that there won't be much in the document at this point - it has just been created. As Boris Zbarsky notes in the comments, you probably want to add a DOMContentLoaded event listener to wait for the document contents to become available:

var wnd = subject.QueryInterface(Components.interfaces.nsIDOMWindow);
wnd.addEventListener("DOMContentLoaded", function(event)
{
  dump(wnd.document.documentElement.innerHTML);
}, false);