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cell phone wireless
What Is Wap?
By Jim Pretin
I have been designing websites since 1996. In the beginning, it was easy. Someone called me with a project, they sent me the content for their website, which I would then upload to Microsoft Frontpage or a text editor, insert some HTML tags for formatting and some graphics to make the site colorful, and the job was finished.
The revolution changed everything. Almost every electronic device now comes equipped with access to the web and email. Palm tops, laptops, cell phones, even computer screens installed in automobiles are now connected to the internet. The web browsers and operating systems installed on these devices are often very different from what is installed on an ordinary desktop PC. Many elements of the HTML programming language are not compatible with some of these platforms. As a result, web design has completely changed. Cross-platform programming languages and specifications have been created so that websites can be viewed on any PC or gadget.
Now that you have a basic understanding of how and why programming has changed, you are now ready for a brief introduction to the main topic of this article, WAP (Wireless Application Protocol). WAP is an open international standard for applications that use communication. Its principal application is to enable access to the internet from a mobile phone or PDA.
Before we begin to discuss Application Protocol, you should first know a little bit about a language called XML. It is a language that enables programmers to define data without telling the web browser how to display it, because XML files are simple text files. As a result, XML data can be displayed on any web browser. This is significant, because as we have already established, web browsers have a hard time with HTML. XML solves this dilemma by putting data in a format that be displayed across all platforms.
WAP browsers are browsers that run on devices such as cell phones. The WAP protocol understands WML (Wireless Markup Language), which is written in XML. In addition to XML, WML uses some Javascript, which is referred to as WMLScript. However, the Javascript is not actually coded directly into the WML page; it is referenced by using a script URL, which must be compiled into byte code on a server before the Javascript can run on the browser.
Wireless Markup Language uses tags, just like HTML. However, the tags are case sensitive. The most important tag that is used is the card tag. WAP pages are known as decks, and they consist of a set of cards, which contain code sandwiched between the opening and closing tags of each card. The cards within the document are then linked to each other.
When a web browser prepares to present the contents of a web page to the user, it downloads all of the cards in the deck at the beginning when the page first loads, and then is able to display the web page and everything in it without making any additional visits to the server.
Within the code, there are usually two main types of tasks called go and previous. The go task tag causes a switch to a new card within the deck. The previous task tag causes the action to switch to the card that was accessed previously. The other two types of tasks worth noting are the refresh task, which will refresh any variables that are being used and refresh the screen if the variables appear on the screen, and the noop task, which stops any further operations from being performed. There are many other nifty tasks and elements that are used in WML such as the timer element. An example of the timer element in action would be to cause a message that is generated by a task in one of the cards to appear on the screen for 3 seconds before disappearing and moving on to the next card in the deck.
If you make a living as a web designer, you need to learn to create pages that are WML enabled for WAP browsers. If you are unable to program a web site so that it can be displayed on a computer, then your clients will be very unhappy. internet usage is proliferating. Not creating web sites that can be displayed effectively across all platforms is tantamount to career suicide. If you are not familiar with Markup Language, I recommend that you enroll in some courses at a local computer programming institute, or purchase some tutorials online. The syntax for the WML language is not too complicated, so if you already have extensive web design experience, learning the language should be relatively easy.
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