Greasemonkey Hacks

Hack #2. Provide a Default Configuration

User scripts can be self-describing; they can contain information about what they do and where they should run by default.

Every user script has a section of metadata, which tells Greasemonkey about the script itself, where it came from, and when to run it. You can use this to provide users with information about your script, such as its name and a brief description of what the script does. You can also provide a default configuration for where the script should run: one page, one site, or a selection of multiple sites.

The Code

Save the following user script as helloworld.user.js:

	Example: Hello World metadata

	// ==UserScript==
	// @name		Hello World
	// @namespace	http://www.oreilly.com/catalog/greasemonkeyhcks/
	// @description	example script to alert "Hello world!" on every page
	// @include		*
	// @exclude		http://oreilly.com/*
	// @exclude		http://www.oreilly.com/*
	// ==/UserScript==

	alert('Hello world!');

There are five separate pieces of metadata here, wrapped in a set of Greasemonkey-specific comments.

Wrapper

Let's take them in order, starting with the wrapper:

	// ==UserScript==
	//
	// ==/UserScript==

These comments are significant and must match this pattern exactly. Greasemonkey uses them to signal the start and end of a user script's metadata section. This section can be defined anywhere in your script, but it's usually near the top.

Name

Within the metadata section, the first item is the name:

	// @name	Hello World

This is the name of your user ...