Question

I’m playing with chrome extensions, trying to learn how to use them.

Is it possible for me to write an extension which injects a widget into my website whenever someone with the extension visits it? Can you recommend a sample application or tutorial that I can look at, which showcases something like this?

Answer 1

You can only inject JavaScript and CSS through Chrome extensions.
To inject the script or css your manifest.json should look something like this:

    {
        "name": "Website addon",
        "version": "1.0",
        "manifest_version": 1,
        "description": "Addon for your website",
        "content_scripts": [
          {
            "matches": ["*://yourWebsite.com/*", "*://*.yourWebsite.com/*"],
            "js": ["yourJS.js"]
            "css": ["yourCSS.css"]
          }
        ]
    }

This will add yourJS.js and yourCSS.css to all websites on yourWebsite.com

Here is a link to a tutorial from google: http://code.google.com/chrome/extensions/content_scripts.html