How to disable facebook hotkeys with Chrome extension?

Question

I have created a Chrome extension that uses the hotkeys [Alt]+[0...9] only to discover facebook uses the same hotkeys. Is there any way possible my extension could disable f

Answer 1

Your intuition is correct, the JavaScript that runs from a content script as part of a Chrome Extension is run in a sandbox that does not have access to the JavaScript that is executed in the containing page.

Per the Chrome doc on Content Scripts:

However, content scripts have some limitations. They cannot:
*  Use chrome.* APIs (except for parts of chrome.extension)
*  Use variables or functions defined by their extension's pages
*  Use variables or functions defined by web pages or by other content scripts

First off, I would recommend that you consider different shortcut keys. Overriding the functionality of existing shortcut keys for your own extension could provide a jarring user experience for someone that is expecting the Facebook shortcut key. Imagine if an extension overrode the ctrl-c and ctrl-p shortcuts that are a part of the desktop OS for copy and paste - I think you would have some upset users that would probably remove the thing that changed the behavior they learned prior.

However, if you are insistent, then here is a workaround to loading JavaScript that will execute in the context of the containing page:

Edit: Updated per comment to reference JS file in a plugin instead of one hosted on the web

First, you will need to create a JavaScript file in your chrome plugin: override-fb-hotkeys.js.

First, you will need to host a JavaScript file somewhere on the web that contains the script that you want to execute in the page, let us say you host it at: http://example.com/override-fb-hotkeys.js.

Then, from your content script, you can insert a script tag into the DOM that references your JavaScript file, something like this:

    var script = document.createElement('script');
    script.setAttribute("type", "text/javascript");
    script.setAttribute("async", true);
    script.setAttribute("src", chrome.extension.getURL("override-fb-hotkeys.js")); //Assuming your host supports both http and https
    var head = document.head || document.getElementsByTagName( "head" )[0] || document.documentElement;
    head.insertBefore(script, head.firstChild)

The JavaScript will then be fetched and executed in the context of the containing page, not the sandboxed code from the Chrome plugin.