Wireless Markup Language - AbsoluteAstronomy.com

Wireless Markup Language (WML), based on XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

, is a markup language

Markup language

A markup language is a modern system for annotating a text in a way that is syntactically distinguishable from that text. The idea and terminology evolved from the "marking up" of manuscripts, i.e. the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts...

intended for devices that implement the Wireless Application Protocol

Wireless Application Protocol

Wireless Application Protocol is a technical standard for accessing information over a mobile wireless network.A WAP browser is a web browser for mobile devices such as mobile phones that uses the protocol.Before the introduction of WAP, mobile service providers had limited opportunities to offer...

(WAP) specification, such as mobile phones. It provides navigational support, data input, hyperlinks, text and image presentation, and forms, much like HTML

HTML

HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

(HyperText Markup Language). It preceded the use of other markup languages now used with WAP, such as HTML itself, and XHTML

XHTML

XHTML is a family of XML markup languages that mirror or extend versions of the widely-used Hypertext Markup Language , the language in which web pages are written....

(which are gaining in popularity as processing power in mobile devices increases).

WML history

Building on Openwave's HDML

Handheld Device Markup Language

The Handheld Device Markup Language is a markup language intended for display on handheld computers, information appliances, smartphones, etc.. It is similar to HTML, but for wireless and handheld devices with small displays, like PDA, mobile phones and so on.It was originally developed in about...

, Nokia's "Tagged Text Markup Language" (TTML) and Ericsson's proprietary markup language for mobile content, the WAP Forum created the WML 1.1 standard in 1998. WML 2.0 was specified in 2001, but has not been widely adopted. It was an attempt at bridging WML and XHTML Basic

XHTML Basic

XHTML Basic is an XML-based structured markup language primarily used for simple user agents, typically mobile devices.XHTML Basic is a subset of XHTML 1.1, defined using XHTML Modularization including a reduced set of modules for document structure, images, forms, basic tables, and object support...

before the WAP 2.0 spec was finalized. In the end, XHTML Mobile Profile

XHTML Mobile Profile

XHTML Mobile Profile is a hypertextual computer language standard designed specifically for mobile phones and other resource-constrained devices....

became the markup language used in WAP 2.0. The newest WML version in active use is 1.3.

WML markup

WML documents are XML documents that validate against the WML DTD (Document Type Definition

Document Type Definition

Document Type Definition is a set of markup declarations that define a document type for SGML-family markup languages...

)
. The W3C Markup Validation service (http://validator.w3.org/) can be used to validate WML documents (they are validated against their declared document type).

For example, the following WML page could be saved as "example.wml":

"http://www.wapforum.org/DTD/wml_1.1.xml" >

This is a sample WML page.

A WML document is known as a “deck”. Data in the deck is structured into one or more “cards” (pages) – each of which represents a single interaction with the user. The introduction of the terms "deck" and "card" into the internet and mobile phone communities was a result of the user interface software and its interaction with wireless communications services having to comply with the requirements of the laws of two or more nations.

WML decks are stored on an ordinary web server

Web server

Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....

configured to serve the text/vnd.wap.wml MIME type in addition to plain HTML and variants. The WML cards when requested by a device are accessed by a bridge WAP gateway

WAP gateway

A WAP gateway sits between mobile devices using the WAP protocol and the World Wide Web, passing pages from one to the other much like a proxy. This translates pages into a form suitable for the mobiles, for instance using the Wireless Markup Language...

, which sits between mobile devices and the World Wide Web, passing pages from one to the other much like a proxy

Proxy server

In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...

. The gateways send the WML pages on in a form suitable for mobile device reception (WAP Binary XML

WBXML

WAP Binary XML is a binary representation of XML. It was developed by the WAP Forum and is now maintained by the Open Mobile Alliance as a standard to allow XML documents to be transmitted in a compact manner over mobile networks and proposed as an addition to the World Wide Web Consortium's...

). This process is hidden from the phone, so it may access the page in the same way as a browser accesses HTML

HTML

HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

, using a URL (for example, http://example.com/foo.wml). (Provided the mobile phone operator has not specifically locked the phone to prevent access of user-specified URLs.)

WML has a scaled down set of procedural elements which can be used by the author to control navigation to other cards.

Consider a service that lets you enter a zip code, and obtain a list of clickable phone numbers of pizza parlors and taxicabs in your immediate location:

Call A Taxi:

903-555-1212

Mobile devices are moving towards support for greater amounts of XHTML

XHTML

XHTML is a family of XML markup languages that mirror or extend versions of the widely-used Hypertext Markup Language , the language in which web pages are written....

and even standard HTML as processing power in handsets increases. These standards are concerned with formatting and presentation. They do not however address cell-phone or mobile device hardware interfacing in the same way as WML.

WML support in desktop browsers

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

based browsers (Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...

, SeaMonkey

SeaMonkey

SeaMonkey is a free and open source cross-platform Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code...

, MicroB

MicroB

MicroB is a mobile web browser developed by Nokia for use in smartphones and mobile devices that run the Maemo operating system. The browser is Mozilla-based and uses the Gecko layout engine....

) can interpret WML by WMLBrowser addon.

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

WML history

WML markup

WML support in desktop browsers

See also

External links