This is a quick list of useful code snippets (small code samples) available for developers of extensions for the various Mozilla applications. Many of these samples can also be used in XULRunner applications, as well as in actual Mozilla code itself.

These examples demonstrate how to accomplish basic tasks that might not be immediately obvious.

General

Examples and demos from MDN articles

A collection of examples and demos from articles.

Window code

Opening and manipulating windows

Toolbar

Toolbar related code

Sidebar

Sidebar related code

Forms

Forms related code

XML

Code used to parse, write, manipulate, etc. XML

File I/O

Code used to read, write and process files

Drag & Drop

Code used to setup and handle drag and drop events

Dialogs

Code used to display and process dialog boxes

Alerts and Notifications

Modal and non-modal ways to notify users

Preferences

Code used to read, write, and modify preferences

JS XPCOM

Code used to define and call XPCOM components in JavaScript

Running applications

Code used to run other applications

<canvas> related

WHAT WG Canvas-related code

Signing a XPI

How to sign an XPI with PKI

Delayed Execution

Performing background operations.

Miscellaneous

Miscellaneous useful code fragments

HTML to DOM

Using a hidden browser element to parse HTML to a window's DOM

JavaScript libraries

Here are some JavaScript libraries that may come in handy.

StringView

A library that implements a StringView view for JavaScript typed arrays. This lets you access data in typed arrays using C-like string functions.

Rosetta

By default, the only possible standardized scripting language for HTML is ECMAScript. Hence, if you are going to use another scripting language you might expect that most of the browsers will not recognize it. Nevertheless, the increasing computational power of modern browsers together with the introduction of typed arrays in ECMAScript allow us, in theory, to build full virtual machines in pure ECMAScript. Therefore, it is also possible, in theory, to use ECMAScript for a smaller task: parsing exotic programming languages (i.e., creating compilers). This snippets shows a possible way to start from.

Browser-oriented code

Tabbed browser code (Firefox/SeaMonkey)

Basic operations, such as page loading, with the tabbed browser, which is the heart of Mozilla's browser applications

Cookies

Reading, writing, modifying, and removing cookies

Page Loading

Code used to load pages, reload pages, and listen for page loads

Interaction between privileged and non-privileged code

How to communicate from extensions to websites and vice-versa.

Downloading Files

Code to download files, images, and to monitor download progress

Password Manager

Code used to read and write passwords to/from the integrated password manager

Bookmarks

Code used to read and write bookmarks

JavaScript Debugger Service

Code used to interact with the JavaScript Debugger Service

SVG

General

General information and utilities

SVG Animation

Animate SVG using JavaScript and SMIL

SVG Interacting with Script

Using JavaScript and DOM events to create interactive SVG

Embedding SVG in HTML and XUL

Using SVG to enhance HTML or XUL based markup

XUL Widgets

HTML in XUL for Rich Tooltips

Dynamically embed HTML into a XUL element to attain markup in a tooltip

Label and description

Special uses and line breaking examples

Tree

Setup and manipulation of trees using XUL and JS

Scrollbar

Changing style of scrollbars. Applies to scrollbars in browser and iframe as well.

Autocomplete

Code used to enable form autocomplete in a browser

Boxes

Tips and tricks when using boxes as containers

Tabbox

Removing and manipulating tabs in a tabbox

Windows-specific

Finding Window Handles (HWND) (Firefox)

How to use Windows API calls to find various kinds of Mozilla window handles. Window handles can be used for IPC and Accessibility purposes.

Using the Windows Registry with XPCOM

How to read, write, modify, delete, enumerate, and watch registry keys and values.

External links

The content at MozillaZine Example Code is slowly being moved here, but you can still find useful examples there for now.