Update 2016: Google Chrome released the storage API: https://developer.chrome.com/docs/extensions/reference/storage/ It is pretty easy to use like the other Chrome APIs and you can use it from any page context within Chrome. // Save it using the Chrome extension storage API. chrome.storage.sync.set({‘foo’: ‘hello’, ‘bar’: ‘hi’}, function() { console.log(‘Settings saved’); }); // Read it using the storage … Read more
The following method registers an application to a URI Scheme. So, you can use mycustproto: in your HTML code to trigger a local application. It works on a Google Chrome Version 51.0.2704.79 m (64-bit). I mainly used this method for printing document silently without the print dialog popping up. The result is pretty good and … Read more
Since content scripts run in an “isolated world” the JS variables of the page cannot be directly accessed from an extension, you need to run code in page’s main world. WARNING! DOM element cannot be extracted as an element so just send its innerHTML or another attribute. Only JSON-compatible data types can be extracted (string, … Read more
YouTube has started a trial with pushState-based navigation. In general, such navigations can only be detected within content scripts by injecting code that intercept calls to history.replaceState / history.pushState (or by using the chrome.webNavigation.onHistoryStateUpdated event in the background page). The remainder of this answer is specific to YouTube. YouTube shows a (red) progress bar on … Read more
There’s a way to allow a content script heavy extension to continue functioning after an upgrade, and to make it work immediately upon installation. Install/upgrade The install method is to simply iterate through all tabs in all windows, and inject some scripts programmatically into tabs with matching URLs. Obviously, you have to do it in … Read more
The easy way The easiest way to get an extension ID is to generate the .pem file and extract the extension ID using the steps described in my other answer (read the part below the image). The command-line way The rest of this answer is for those who want to generate the extension ID with … Read more
By default you cannot run on a chrome:// url page. However, there is an option in chrome://flags/#extensions-on-chrome-urls: Extensions on chrome:// URLs (Mac, Windows, Linux, Chrome OS, Android) Enables running extensions on chrome:// URLs, where extensions explicitly request this permission. You still have to specify pages that your extension can run on and wildcards are not … Read more
Your code is correct as written, it works and outputs to console. If you are not seeing it, then you are, probably, looking at the wrong console. 1. Firefox Mozilla describes what extension output can be seen in which console in their Debugging article. Browser Console The Browser Console no longer shows output from WebExtensions … Read more