Wireless Markup
Language(WML)
Topics
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Introduction
Constraints
Supporting Documentation
Main Functions
Deck/Cards Design
WML Elements
Client - Server Access
Conclusions
Application
WML Web-site
Introduction
 WML was formed to create the global
wireless protocol specification that works
across differing wireless network
technology types, for adoption by
appropriate industry standards bodies.
Introduction
 Based on XML.
 Developed by the WAP forum.
 WML provides a schema for describing
data so that it can be viewed on (WAP
capable) Mobile phones and Personal
Digital Assistants.
WAP Forum
 The WAP Forum is the industry association
comprising of hundreds of members.
 De-facto world standard for wireless
information and telephony services.
 Digital mobile phones and other wireless
terminals.
WML Constraints
 Small display.
 Limited user input facilities.
 Narrowband network connection.
 Limited memory and computational
resources.
Documentation
 WML specification describes WML, including its
semantics, its [XML] document type definition
(DTD) and its encoding extensions.
 WML Script specification describes the scripting
language, WML Script, including its lexical and
syntactic grammar, its transfer format and a
reference byte code interpreter.
 WML Script Standard Libraries describes
standard library programs including a language
library, a string library, a dialog library, a
floating-point library, a browser library and a
URL library.
Main Functions
 Text presentation and layout.
 Deck/Card organizational metaphor - all
information in WML is organized into a
collection of cards and decks.
 Inter-card navigation and linking - WML
includes support for explicitly managing the
navigation between cards and decks.
 String parameterization and state management all WML decks can be parameterized, using a
state model.
Decks/Cards
 Deck: A single WML document (i.e. the
elements contained within the <wml>
document element) is known as a deck.
 Card: A single interaction between a user
agent and a user is known as a card.
Features
 Multiple screens can be downloaded to the
client in a single retrieval.
 User selections or entries can be handled
and routed to already loaded cards.
 Eliminates excessive transactions with
remote servers.
 Multiple cards can be split-up into multiple
decks. (flexibility for memory constraints)
WML Elements
 Document Element:
<code><wml></code>
 Deck/Card Elements: wml, card, template,
head, access, meta
 Event Elements: do, ontimer,
onenterforward, onenterbackward, onpick,
onevent, postfield,
WML Elements
 Tasks: go, prev, refresh, noop
 Variables: setvar
 User input: input, select, option, optgroup,
fieldset.
 Anchors, Images, and Timers: a, anchor,
img, timer.
 Text Formatting: b, p, table, tr, td.
Element Syntax
 <element> element value </element>
 Login Example WML
<?xml version='1.0'?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"
"http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id="Login" title="Login">
<do type="accept" label="Password">
<go href="#Password"/>
</do>
<p>
UserName:
<select name="name" title="Name:">
<option value="John Doe">John Doe</option>
<option value="Paul Smith">Paul Smith</option>
<option value="Joe Dean">Joe Dean</option>
<option value="Bill Todd">Bill Todd</option>
</select>
</p>
</card>
<card id="Password" title="Password:">
<do type="accept" label="Results">
<go href="#Results"/>
</do>
<p>
Password: <input type="text" name="password"/>
</p>
</card>
<card id="Results" title="Results:">
<p>
You entered:<br/>
Name: $(name)<br/>
Password: $(password)<br/>
</p>
</card>
</wml>
Calling Server Script
 Dynamically connect to remote servers opens up
every WAP device to the world of Internet
messaging, enterprise data, and e-commerce.
 WAP gateway.
 Popular server scripting tools: Java Servlets,
JavaScript, ASP, or Perl.
 <go href="http://127.0.0.1/WML/Inventory.asp"
method="post"><postfield name="Items"
value="$(Items)"/>
</go>
Conclusions
 Entirely new, exciting platform on which
to deploy applications.
 Tradeoffs and challenges: server roundtrips, bandwidth, and display sizes.
 WAP opens the door to a new era in
application development and deployment.
HTML to WML
Server Side
Client Side
Proxy Server
WML
Gateway
HTML
Conversion
V1
V2
Rearrange
V3
User profile
Device profile
End User
WML Web-Sites
 http://www.oasis-open.org/cover/wapwml.html
 http://www.wapforum.org/docs/copyright.h
tm
 http://www.wirelessdevnet.com/channels/w
ap/training/wml.html