dotjs

dotjs is a Google Chrome extension that executes JavaScript files in ~/.js based on their filename.

If you navigate to http://github.com/, dotjs will execute all ~/.js/github.com/*.js files, in alphabetical order.

This makes it super easy to spruce up your favorite pages using JavaScript. The scripts in github.com/ won't be run on sub-domains, like gist.github.com, dotfiles.github.com et c, where they might wreak all sorts of havoc from not seeing the kind of pages they were written for. (*)

If you want to run something on all *.github.com sites; www.google.com, images.google.com, et c, you can put js files in .google.com instead. These will run before more specific files in google.com.

For code you want to run on all sites, ALL/*.js is loaded first of all, all over the web, meaning you can stick plugins or helper functions in there.

Bonus: files in ~/.js have jQuery 1.9 loaded, regardless of whether the site you're hacking uses jQuery.

(*) Double Bonus: A handy tool for writing scripts defensively, which automatically check if a page has all the script's DOM prerequisites before continuing -- and then helpfully hands you all those nodes in a well-named, structured manner is on, which you can find and fork here: https://gist.github.com/3944489

(a cool bonus of this practice, is that it separates page structure from script code, so you can see what assumptions about the page break, when sites evolve, and fix it -- often without needing to change logic)

GreaseMonkey user scripts are great, but you need to publish them somewhere and re-publish after making modifications. With dotjs, just add or edit files in ~/.js.

Example

$ cat ~/.js/github.com.js
// swap github logo with trollface
$('a[class^=header-logo-]').html(
    $('<img>')
        .attr('src', '//bit.ly/ghD24e')
        .css({'width': 'auto', 'height': '22px'})
    );

How It Works

Chrome extensions can't access the local filesystem, so dotjs runs a tiny web server on port 3131 that serves files out of ~/.js.

You don't have to worry about starting or stopping this web server because we put a pretty great plist into ~/Library/LaunchAgents that handles all that for us.

The dotjs Chrome extension then makes ajax requests to http://localhost:3131/convore.com.js any time you hit a page on convore.com, for example, and executes the returned JavaScript.

Requires

OS X
Ruby 1.8
rake (gem install rake)
Google Chrome
/usr/local/bin in your $PATH

Install it

git clone http://github.com/defunkt/dotjs
cd dotjs
rake install

Now open https://localhost:3131 in Chrome and follow these steps:

Click the "X" Padlock icon in the address bar
Click "Certificate Information"
Drag the large cert icon to your desktop
Open it with Keychain
Configure its Trust section as shown: http://cl.ly/Pdny

Finally install the Google Chrome extension:

http://bit.ly/dotjs

Uninstall it

rake uninstall

Credits

Icon: http://raphaeljs.com/icons/
jQuery: http://jquery.com/
Ryan Tomayko for:

"I almost wish you could just stick JavaScript in ~/.js. Do you know what I'm saying?"

junkblocker/dotjs