XBL (''XML Binding Language'') is an

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

-based

markup language A markup language is a Encoding, text-encoding system which specifies the structure and formatting of a document and potentially the relationships among its parts. Markup can control the display of a document or enrich its content to facilitate au ...

for altering the behavior of XUL widgets. It was devised at Netscape in the late 1990s as an extension of XUL. The primary use of XBL was in the

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements curr ...

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

, but Mozilla deprecated it in 2017 and completely removed it from Firefox in 2019. However, the UXP fork of Firefox intends to continue supporting XBL indefinitely. Mozilla attempted to standardize XBL 2.0 via

W3C The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working together in ...

in 2007, but due to lack of interest from other web browser vendors, abandoned it in 2012. The Shadow DOM specification acknowledges XBL as a strong influence.

Overview

XUL defines the

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine fro ...

layout of an application. CSS rules can be used to change the appearance of various XUL elements. But XBL is needed to alter the behavior of a XUL widget, such as a scroll bar. An XBL file contains bindings, each of which describes the behavior of a XUL widget. The root element of an XBL file is the element, which contains one or more elements. Each element declares one binding, which can be attached to any XUL element. It may also possess an id attribute. A binding is assigned to an element by setting the CSS property -moz-binding to the URL of the binding's file. For example: scrollbar

References

{{DEFAULTSORT:Xbl Declarative markup languages Markup languages Mozilla World Wide Web Consortium standards XML-based standards

Overview

See also

References