This is a Firefox Add-on port of defunkt's Chrome extension https://github.com/defunkt/dotjs.

dotjs is a Firefox Add-on that executes JavaScript and CoffeeScript files in ~/.js based on their filename and the domain of the site you are visiting.

If you navigate to http://www.google.com/, dotjs will execute ~/.js/google.com.js and/or ~/.js/google.com.coffee. If you have a ~/.js/default.js, it will execute on every page you visit. Also, you can put site specific .css files in ~/.css (C:\Users\<username>\css\. in Windows 7). default.css loads in all sites.

This makes it super easy to spruce up your favorite pages using JavaScript and CSS.

Bonus: files in ~/.js have jQuery 1.12.4 loaded, regardless of whether the site you're hacking uses jQuery.

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.

$ cat ~/.js/github.com.js
// swap github logo with trollface
$('#header .site-logo img')
.css('width', '100px')
.css('margin-top', '-15px')
.attr('src', 'https://img.skitch.com/20110207-x4s8eys3uy641yk72jigt38bby.png');

Sometimes, you don’t want to target a whole domain, but only a path.

You can use the @-moz-document Mozilla Extension:

/* Full path */
@-moz-document url-prefix(http://www.w3.org/Style/) {
    /* CSS here */
}

/* Regex */
@-moz-document regexp("^https?:\/\/www\.w3\.org\/Style\/.*") {
    /* CSS here */
}

Documentation: https://developer.mozilla.org/en/CSS/@-moz-document

You can test the window.location object:

// Search for a string
if (window.location.pathname.indexOf('/Style/') === 0) {
    // JS here
}

// Regex
if (/^\/Style\/.*/.test(window.location.pathname)) === 0) {
    // JS here
}

Documentation: https://developer.mozilla.org/en/DOM/window.location

• You can install from Mozilla Add-ons site: https://addons.mozilla.org/en-US/firefox/addon/dotjs/
• Or from source. Refer to the Add-on SDK Docs: https://developer.mozilla.org/en-US/Add-ons/SDK

• jpm: https://developer.mozilla.org/en-US/Add-ons/SDK/Tools/jpm

• djl: https://github.com/djl
• tdolsen: https://github.com/tdolsen
• canuckistani: https://github.com/canuckistani
• bpierre: https://github.com/bpierre

v1.13 Fix for subdomains (Issue #43).

v1.12 Now scripts run in private browser windows (Issue #35). Fix issue where scripts were loaded multiple times. Now using jpm.

v1.11 This version now looks up the files recursively for the domains. So for example, for "www.example.com" it will attempt to load: www.example.com.js example.com.js com.js

v1.10 Fixed bug with default.js (Issue #28)

v1.9 Performance optimization. Load content scripts on DOM ready.

v1.8 Updated jquery to v1.9 and coffeescript to v1.4.

v1.7 Updated to version 1.7 of addon sdk along with some optimizations.

v1.6: Leaner, meaner dotjs. A bunch of optimizations by canuckistani (Thanks! \o/).

v1.3: Only load into into the main tab document (vs iframes, etc.).Improves memory usage and performance.

v1.2: Updated to jQuery 1.7.1 and some cleanup (Thanks djl!).

v0.9: CSS support!

v0.8: Windows support! Put your scripts in a js folder under your home directory (C:\Users\<username>\js\. in Windows 7).

v0.7: CoffeeScript support! ~/.js/example.com.coffee gets transpiled to JavaScript and executed.

• defunkt: https://github.com/defunkt/dotjs
• jQuery: http://jquery.com/
• Ryan Tomayko for:

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