Inside WAP

The Wireless Application Protocol (WAP) is an open, global specification that gives mobile users with wireless devices the power to access and interact with information and services instantly. The rapid acceptance of this technology has opened up unprecedented opportunities for developers to use their existing internet-based skills to create and deploy a new generation of wireless applications.

Inside WAP is a clear and simple guide and reference to programming with WAP, using a wealth of illustrated examples to help readers visualize the development process and lay a solid foundation for their own applications.

Inside WAP explains:

The basics of WAP programming
The essential information about the architecture and protocols - no more than you need to know to start programming.

WML
How to write programs with the WML formatting language - this forms the basis for simple WAP services, as well as for more sophisticated applications. Learning WML is straightforward if you already have some knowledge of HTML.

WMLScript
A walk through all WMLScript commands and libraries, enabling you to create short WAP applications. WMLScript adds dynamic and interactive elements to your WAP documents.

CGI Programming
The basics of server side CGI programming, including some WAP-CGI solutions for a company intranet. CGI can be used to create versatile and impressive applications for mobile devices.

Java Servlets
Servlet programming, Java basics , and how to install servlets on WWW and WAP servers.

The Nokia WAP Server
A complete server for WAP content and applications, or a WAP-compliant gateway, allowing WAP devices to communicate with content servers. This section also describes how to transfer WAP documents to a server and how to publish them.

CD image
Every example in this book has been tested on a Nokia 7110 phone, an Ericsson MC218 palmtop, the Phone.com UP.SDK 3.2 emulator and the Nokia WAP Toolkit program. Version 2.0 of the Nokia WAP toolkit is included on the accompanying CD-ROM.
The CD also features: source code for all the examples in the book, the Nokia WAP Server, plus tools for creating and testing CGI programs for web servers.

Contents

Foreword vii

Contents ix

Introduction 1

2 WML 13
2.1 WML document structure 15
2.1.1 Decks and cards 16
2.1.2 The meta information of a document 22
2.2 Text formatting 24
2.2.1 Highlighting text 24
2.2.2 Line breaks and paragraphs 25
2.2.3 Tables 29
2.3 Links, images and timers 35
2.4 Events 47
2.4.1 do 47
2.4.2 ontimer 49
2.4.3 onenterforward 52
2.4.4 onenterbackward 55
2.4.5 onpick 57
2.4.6 onevent 57
2.4.7 postfield 58
2.4.8 Overriding events 59
2.5 Tasks 61
2.5.1 go 61
2.5.2 prev 65
2.5.3 refresh 66
2.5.4 noop 68
2.6 Variables 70
2.7 Forms 77
2.7.1 input 78
2.7.2 select 85
2.7.3 option 89
2.7.4 optgroup 93
2.7.5 fieldset 97
2.8 WML: a summary 98

3 WMLScript 105
3.1 Calling WMLScript functions 108
3.2 Variables and data types 111
3.3 Operators 122
3.4 Functions 132
3.5 Statements and expressions 141
3.6 Type conversions 156
3.7 Standard libraries 160
3.7.1 Lang 162
3.7.2 Float 181
3.7.3 String 189
3.7.4 URL 214
3.7.5 WMLBrowser 233
3.7.6 Dialogs 238
3.8 Summary of the WMLScript language 243

4 CGI programming 254
4.1 Theory of CGI programming 256
4.1.1 The GET method 258
4.1.2 The POST method 259
4.1.3 Header information 259
4.1.4 Environment variables 260
4.1.5 Processing form data 260
4.1.6 Printing the result 261
4.1.7 Forms 262
4.1.8 Security 262
4.2 Perl basics 264
4.2.1 Data types 270
4.2.2 Operators 271
4.2.3 Control structures 275
4.2.4 Processing strings 284
4.3 Dynamic documents 294
4.4 Processing forms 307
4.5 CGI scripts on an intranet 326

5 Java servlets 349
5.1 Basics of servlet programming 350
5.2 Java basics 358
5.2.1 Data types and operators 361
5.2.2 Control structures 363
5.2.3 Objects and classes 366
5.3 Handling forms with servlets 368
5.4 Servlets on the Nokia WAP Server 375

6 The Nokia WAP Server 383

7 Publishing WAP content 406
7.1 Creating documents and directories 406
7.2 Images in WML documents 409
7.3 Transferring files to a server 412
7.4 WAP device settings 416

8 The future of WAP solutions 418
8.1 WTA 418
8.2 Push technology 421
8.3 Possibilities of the WAP architecture 425

Appendix 1 WML commands and attributes 428
Appendix 2 WMLScript reserved words 431
Appendix 3 WAP device icons 432
Appendix 4 Files on CD-ROM 435
Index 437