Greasemonkey

Hacks –2: Introduction The first thing you need to do to get started with Greasemonkey is install it. Open Firefox and go to http://greasemonkey.mozdev.org. Click the Install Greasemonkey link. Firefox will warn you that it prevented this site from...

A Greasemonkey user script is a single file, written in JavaScript, that customizes one or more web pages. So, before Greasemonkey can start working for you, you need to install a user script. Many user scripts are available at the Greasemonkey ...

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 w...

As described in "Provide a Default Configuration" [Hack #2], Greasemonkey executes a user script based on @include and @exclude parameters: URLs with * wildcards that match any number of characters. This might seem like a simple syntax, but combining...

Once you have a few user scripts running, you might want to temporarily disable some or all of them. There are several different ways to prevent a user script from running. 1.5.1. Disabling a User Script Without Uninstalling It The easiest ...

One of the most important pieces of information about a user script is where it should run. One page? Every page on one site? Multiple sites? All sites? This hack explains several different ways to configure where a user script executes. 1.6.1. ...

Since most user scripts center around adding or removing content from a web page, let's quickly review the standard DOM methods for manipulating content. 1.7.1. Adding an Element The following code adds a new element to the end of the page....

In many of the user scripts I've written, I want to make things look a certain way. Either I'm modifying the page's original style in some way, or I'm adding content to the page and I want to make it look different from the rest of the page. There ar...

Firefox contains a little-known but powerful feature called XPath. XPath is a query language for searching the Document Object Model (DOM) that Firefox constructs from the source of a web page. As mentioned in "Add or Remove Content on a Page" [Hac...

While you're writing a user script, you will undoubtedly need to make changes incrementally and test the results. As shown in "Install a User Script" [Hack #1], Greasemonkey stores your installed user scripts deep within your Firefox profile director...

The actual process of writing user scripts can be frustrating if you don't know how to debug them properly. Since JavaScript is an interpreted language, errors that would otherwise cause a compilation error (such as misspelled variables or function n...

A user script is a single file. Greasemonkey does not provide any mechanism for bundling other resource files, such as image files, along with the JavaScript code. While this might offend the sensibilities of some purists who would prefer to maintain...

Once upon a time, there was a security hole. (This is not your standard fairy tale. Stay with me.) Greasemonkey's architecture has changed substantially since it was first written. Version 0.3, the first version to gain wide popularity, had a fundame...