Get current URL from within a Firefox Addon panel

Question

So I've collected 5 different methods to do this, none of which work from within a panel. Firefox is stunningly effective at blocking access to a basic task.

Here's what I've tried:

• Attempt 1:

  var url = window.top.getBrowser().selectedBrowser.contentWindow.location.href;
  

  Error: window.top.getBrowser is not a function

• Attempt 2:

  var url = window.content.document.location; 
  

  Error: Permission denied to access property 'document'

• Attempt 3:

  var mainWindow = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                 .getInterface(Components.interfaces.nsIWebNavigation)
                 .QueryInterface(Components.interfaces.nsIDocShellTreeItem)
                 .rootTreeItem
                 .QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                 .getInterface(Components.interfaces.nsIDOMWindow);
  var url = mainWindow.getBrowser().selectedBrowser.contentWindow.location.href;
  

  Error: Permission denied to create wrapper for object of class UnnamedClass

• Attempt 4:

  var url = window.content.location.href;
  

  Error: Permission denied to access property 'href'

• Attempt 5:

  var currentWindow = Components.classes["@mozilla.org/appshell/window-mediator;1"].getService(Components.interfaces.nsIWindowMediator).getMostRecentWindow("navigator:browser");
  var currBrowser = currentWindow.getBrowser();
  var url = currBrowser.currentURI.spec;
  

  Error: Permission denied to get property XPCComponents.classes

Coding this for Chrome was a breeze. Not sure why this is so tough for FF.

Anyone got a solution?

Answer 1

I think you can use firefox local object:

var url = gBrowser.contentDocument.location;

Answer 2

I guess "Firefox Addon panel" refers to the Addon SDK's panel module?

If so you're probably trying to use those snippets in a content script. Instead you have to send an event to the main addon's code (example), and in the main addon's code use the tabs module:

require("tabs").activeTab.url

[update] complete testcase, which works for me:

// http://stackoverflow.com/questions/7856282/get-current-url-from-within-a-firefox-addon-panel
exports.main = function() {
  var panel = require("panel").Panel({
    contentURL: "data:text/html,<input type=button value='click me' id='b'>",
    contentScript: "document.getElementById('b').onclick = " +
                   "function() {" +
                   "  self.port.emit('myEvent');" +
                   "}"
  });
  panel.port.on("myEvent", function() {
    console.log(require("tabs").activeTab.url)
  })
  require("widget").Widget({
    id: "my-panel",
    contentURL: "http://www.google.com/favicon.ico",
    label: "Test Widget",
    panel: panel
  });  
};