Page 189 - DCAP512_WAP_AND_WML

Unit 13: Writing for HTML and WML

 WML is part of the WAP standard and its use is required. Notes
 Transmission of WML (WMLC) documents requires less bandwidth compared to HTML
documents because WML documents are simpler and WML is compressed before it is sent
to the WAP device.
 Compared to HTML documents, displaying WML documents requires less processing
power and memory. Consequently, a WAP device can work with a less powerful (cheaper)
CPU and the use of less power means that the battery can operate longer without recharging.
 WML provides support for limited graphics with a limited gray scale.

Is WML A Programming Language?

Most software developers agree that HTML (by itself, without JavaScript) is only a markup
language and not a true programming language. HTML lacks variable assignments, control
flow statements, and conditionals. WML, however, is much closer to a programming language
if not squarely in that camp.
WML supports variables. The <setvar> tag assigns a value to an alphanumeric name as follows:
<setvar name=”index” value=”1">

Accessing a variable in WML is similar to Perl:
<a href=”page_$(index).wml”>Next page</a>
WML supports control flow through tasks. It also supports events including timer events with
the <timer> tag. These features make things like form validation in the browser easier for
developers to implement in WML than HTML. Validating form data in the browser saves
bandwidth over the alternative of sending data to the server for validation.

13.2 Difference between HTML and WML

WML (Wireless Markup Language) and HTML (Hypertext Markup Language) are markup languages,
the main function of which is to serve content from web sites. The main difference between WML
and HTML is the target devices that they aim to serve. HTML was created to serve content to desktop
computers, which have a lot of processing power to spare in parsing and rendering the content.
When the internet began to expand to mobile phones, it became very apparent that mobile phones
do not have the processing power, screen size, and color range to actually work with HTML. Thus,
WML was created as an alternative to HTML in serving web content to mobile phones.

Task Like HTML, WML does specify how the content is to be displayed. Analyze
WML is very limited with the things that it can do. This is necessary in order to simplify the flow
of the page and to minimize the amount of processing needed in rendering the page. It is also
not beneficial to include many or large images into a WML page as it would probably not be
discernable on the very small screens of mobile phones. On the other hand, HTML is quite full
featured, even in its earlier versions. Coders can place multiple images, animations, frames,
tables, and a whole lot more to their pages. Compared to other tasks done with computers,
rendering web pages is relatively very simple and would not load the processor too much.
As technology evolves, computers and mobile phones are also getting better and better. Color
and high resolution screens become more and more common in mobile phones; especially with
smartphones. This improvement means that more phones are able to process HTML pages. The

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