Survey of WML

Mobile Website DevelopmentSurvey of WML

Facilitated by:Michael WakaheTawi Commercial Services LtdJul 2011

Table of Contents

Introduction

Hello World

Introducing JSP

Exercises

Copyright © Tawi Commercial Services Ltd. 2015. All Rights Reserved.

Introduction


Introduction


The WAP Stack

Introduction

WTP (Wireless Transaction Protocol) & WDP

(Wireless Datagram Protocol) provide low-level glue

between the upper levels and the really low-level

communications.

WTLS (Wireless Transaction Layer Security) provides

security services (encryption and authentication).


Introduction

These protocols aren't relevant to normal

application programmers

The second highest level in the stack is the high-

level communications protocol, called WSP

(Wireless Session Protocol).

Provides a complete replacement for HTTP


Introduction

The highest stack level is WAE (Wireless

Application Environment)

This is the part that the user actually sees &

interacts

The WAE aims to provide a World Wide Web-like

model for writing applications


Introduction

The WAE incorporates several key features of the

Web that we are familiar with, e.g. URLs & MIME

content types (such as text/html and image/gif)

Additionally it provides similar replacements for

other features: HTML is replaced with WML (Wireless

Markup Language) & JavaScript is replaced with

WMLScriptCopyright © Tawi Commercial Services Ltd. 2015. All Rights

Reserved.

Introduction

Almost all WAP applications can be written

without using anything outside of these two

languages and WBMP (Wireless Bitmap: the WAP

image format)


Introduction


The WAP Chain of Processing

Hello World


Hello World

We will use Eclipse to compose our WML and deploy

in the Tomcat ROOT folder


Hello World

<?xml version="1.0"?><!DOCTYPE wml PUBLIC"-//WAPFORUM//DTD WML 1.1//EN""http://www.wapforum.org/DTD/wml_1.1.xml"><wml>

<card title="First WML Example">Hello, World!

</card></wml>

Hello World

Note that all tag names are in lowercase

In WML, tag names are case-sensitive

A file of WML represents a deck of cards

This is the reason for the <card> tag

Hello World

Each individual card does behaves very much like an

HTML page

So you can think of a WML deck as being similar to a

number of HTML pages all grouped together


Hello World

Cards in a deck are all downloaded at the same time

So the user has to wait only once & the others can be

accessed almost instantly

Cramming too many cards into a single deck is bad

practice

Ideally maximum of 5 to 6 cards per deck


WML Structure Explained


Valid child tags of <wml> are:

<head>: Defines document metadata and access

control using the <meta> and <access> tags. Zero or

one <head> tags are allowed in a document.

<card>: Defines a card to display in the browser. One

or more <head> tags are allowed in a document.

<template>: Defines global event handlers and

commands for the deck. Zero or one <template> tags

are allowed in a document.

Valid child tags of <card> are:

: Contains text, images, and links. Most user-

accessible and visible content in a WML card is child

content of this tag. Zero or more tags are

allowed in a card.

<pre>: Contains preformatted text. Zero or more

<pre> tags are allowed in a card.Copyright © Tawi Commercial Services Ltd. 2015. All Rights

Reserved.

<do>: Contains commands and actions. Zero or more

<do> tags are allowed in a card.

<timer>: Activates time-based events. Zero or one

<timer> tags are allowed in a card.

<onevent>: Specifies tasks based on different card-

level events. Zero or more <onevent> tags are

allowed in a card.Copyright © Tawi Commercial Services Ltd. 2015. All Rights

Reserved.

Comments:


Other topics in WML include: Special Characters,

Header & Metadata, Text Formatting, Links, Images,

Tables, Timers, Variables, User Input, WMLScript

Browse to http://learnthemobileweb.com/books

for links to WML references and helpful

documentation


http://learnthemobileweb.com/books

http://learnthemobileweb.com/books

Introducing JSP


Introducing JSP

WML can be mixed with JSP and Servlets

Save the following example as a .jsp not as a .wml

Deploy to servlet container (Tomcat)


Introducing JSP<?xml version="1.0"?><!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN""http://www.wapforum.org/DTD/wml_1.1.xml"><%

response.setContentType("text/vnd.wap.wml;charset=UTF-8");int num1 = 9;int num2 = 12;

%><wml>

<card title="First WML Example">My name is <% out.println("Michael"); %>The sum of num1 and num2 is <%= (num1+num2) %>

</card></wml>

Exercises


Exercises

Spot the errors in the following sample:

<wml><card ID=start title='Example of Invalid WML'>

This markup is invalid.</card>

</wml>

Exercises

The WML code sample above has the following syntax

errors:

XML declaration is missing.

DOCTYPE declaration is missing.

ID attribute of <card> tag is uppercase. (Well-formed

WML requires lowercase tags.)

Exercises

Value of the id attribute of the <card> is not

delimited.

Value of the title attribute of the <card> tag is

delimited with single quotes.

 tag is uppercase. (Well-formed WML requires

lowercase tags.)

 tag has an open tag but not matching close tag.Copyright © Tawi Commercial Services Ltd. 2015. All Rights

Reserved.

Exercises

Correct version is as follows:<?xml version="1.0" encoding="utf-8"?><!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.3//EN""http://www.wapforum.org/DTD/wml13.dtd"><wml><card id="start" title="Example of Valid WML">This markup is valid.</card></wml>

Exercises

Write a WML file that shows the first 7 digits of the

Fibonacci Series. Can use JSP and/or servlets.


The End

Michael [email protected]

+254 (0) 20 239 3052 www.tawi.mobi


mailto:[email protected]

http://www.tawi.mobi/

Survey of WML

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