Detect tab URL change inside a Firefox add-on

Question

I have an extension, functional on Chrome, that monitors the active Tab for URL changes.

Specifically, I need to detect when the URL changes, but there is no new pag

Answer 1

If you're using the add-on SDK, you're looking at the wrong docs. Here are the tab docs.

As stated there, you create a listener like so:

var tabs = require("sdk/tabs");

// Listen for tab openings.
tabs.on('open', function onOpen(tab) {
  myOpenTabs.push(tab);
});

// Listen for tab content loads.
tabs.on('ready', function(tab) {
  console.log('tab is loaded', tab.title, tab.url);
});

All the docs you look at should be a subset of developer.mozilla.org/en-US/Add-ons/SDK.

Answer 2

I find that the activate and pageshow events, between the two of them, cover all changes in URL that I can conjure up between switching tabs, opening pages in a new tab, closing tabs, refreshing pages, and typing in new URL's.

var updateURL = function (tab) {
 var oldURL = url;
 var url = tab.url;
 console.log(url);
};

tabs.on("activate", updateURL);
tabs.on("pageshow", updateURL);

Answer 3

Use ProgressListener to be notified about location changes.

To install a listener, convert SDK tab to its raw (old) representation using viewFor. Backward conversion is possible with modelFor and getTabForContentWindow.

const tabs = require("sdk/tabs");
const {viewFor} = require('sdk/view/core');
const {modelFor} = require('sdk/model/core');
const {getBrowserForTab, getTabForContentWindow} = require("sdk/tabs/utils");
const {Ci, Cu} = require("chrome");
Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);

var progressListener = {
QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener, Ci.nsISupportsWeakReference]),
    onLocationChange: function(aProgress, aRequest, aURI) {
        var highLevel= modelFor(getTabForContentWindow(aProgress.DOMWindow));
        console.log("onLocationChange ", highLevel.url);
    }
};

tabs.on('open', function(newTab) {
    var lowLevel = viewFor(newTab);
    var browser = getBrowserForTab(lowLevel);
    browser.addProgressListener(progressListener);
});

Don't forget to remove listeners on extension unload. Tab listeners are removed automagically, but ProgressListeners won't be.

Inspired by Converting to chrome windows