My existence on this planet as a web designer was so easy when I first started developing websites back in 1996. Ah, those were the days. When someone wanted me to create their website, they would provide all the content and some simple design instructions, then I would transfer that content into a simple text file, use basic HTML to give it some formatting, throw in some graphics and a logo, upload the files and collect my money.
Since the turn of the century, the task of designing a website has become intensely complicated, and it continues to become more difficult everyday. When wireless internet access was introduced, every electronic device imaginable came equipped with access to the internet and email. People were surfing the web on their laptops, palm tops, cell phones, even on computer screens installed in automobiles which had previously only been used for navigation.
The birth of the wireless revolution changed the future of programming. These wireless devices often have web browsers that work very differently from the ones installed on an ordinary desktop PC. Many of these browsers are not fully compatible with many elements of the HTML programming language. As a result, people surfing the net on their wireless gadgets can not view many websites that are created using only basic HTML.
To fix the situation, languages and specifications that could be adapted across any platform were created. These new innovations included XML, XHTML, XSL, and several others. XML was a language that defined data without telling the web browser how to display it, as opposed to HTML, which displayed data a certain way. This enabled data to be viewed on virtually any system because an XML file was a simple text file that could be understood and displayed on any browser. XHTML and XSL are complex programming specifications that transformed XML into actual web pages that could be displayed effectively on all browsers.
Now that you have a basic understanding of how and why programming has changed, you are now ready for the main topic of this article, XLink. If you work as a web designer, you probably know how to create a hyperlink. Hyperlinks are created by putting some text in between link tags that delineate the URL that the text placed between the tags is to be linked to.
With XML, creating a hyperlink is more complicated because with XML, there are no predefined tags. With XML, you can create any tags you please and a web browser does not know what any of them mean, because XML merely defines data, it contains no instructions as to how to display the data.
So, to create a hyperlink in XML, you must declare what an XLink is at the top of the XML document using what is called an XML namespace, so that wherever an XLink appears within the document, the web browser will know that the XLink is a hyperlink and display it. The reason why we have to use a namespace is because XML tags are not predefined. By using the XLink namespace, the browser will know that when you apply the XLink marker within your XML document, you are intending to create a hyperlink. Go to the Word Wide Web Consortium (W3) web site to find out how the XLink namespace is created.
It is also possible to create a hyperlink in an XML document that links to another portion of that same XML document, much the same way anchor tags are used in HTML to create a link to another portion of the same web page. Links to different sections of the same web page are often seen on pages that contain Frequently Asked Questions (FAQ), so that the user can click on the question and immediately skip down to the answer which usually appears somewhere else on that same page. With XML, anchor tags are not used. Instead, XPointer Syntax is utilized. XPointer Syntax is very simple to create; like HTML, XPointer makes use of the number sign to indicate the text that is to be anchored to, but the syntax that is used to define the link is not indicated the same way as it is with HTML. To find out how to use XPointer, visit the World Wide Web Consortium (W3) website or perform a search on any search engine for XPointer tutorials.
Every web designer should learn how to use XML, XHTML, and XSL if they want to survive in the constantly changing world of web design. Internet access is now available on almost every electronic device imaginable, so it absolutely necessary to create versatile web sites that can be viewed by everyone regardless of how they connect to the world wide web.
As time progressed, programmers started to realize that they were being stymied by HTML. Web designers wanted to be able to describe data more effectively. This need for a better way to deal with data resulted in the development of a new specification called XML.
What is XML? XML stands for Extensible Markup Language. So, just like HTML, XML is a markup language. A markup language is any language that is used to describe or define information and text. XML is not a substitute for HTML. It is to be used in conjunction with HTML.
HTML focuses on describing how data or text is supposed to be displayed. The XML language does something totally different. XML describes what the data is. So, XML is not something that is apparent on a web page, because it does not actually do anything. As information and data presented on the world wide web became more complex, XML was invented to effectively structure, store, and send this information.
What makes XML truly unique is that there are no predefined tags like we have with HTML. All of the tags used in HTML have already been defined, such as the paragraph tag, the header tag, and all the various style tags. XML is not defined. You can make your own tags!
So, the question is, why do we need XML? Why do we need a more versatile specification like XML to describe data? After all, HTML works fine if used properly, so why do we need XML? Well, the answer is simple. XML is a device independent, cross-platform language.
This is extremely important, because people are now using a wide variety of gadgets to connect to the internet, as almost every electronic device on the market now comes equipped with email and internet access. Cell phones, palm tops, computers installed in automobiles, they all have built-in web access. Each of these devices display text and graphics differently, and utilize different platforms and a variety of web browsers. As a result, someone using a cell phone to access a certain web site may not be able to view the data on that website properly because the browser running on that cell phone might not be able to properly display the HTML. The platforms that run on some of these newfangled products and devices are simply not 100% compatible with HTML.
XML solves this problem by making sure that the most important data on your website can be displayed across all of these different platforms. This is what makes XML so valuable. The other important features of XML is that it enables data to be exchanged between incompatible systems, and because XML files are plain text files, basically anyone using any system can view the contents of the text file.
So, all web designers and programmers should become familiar with and learn to use XML for describing, storing, and sending data. With so many different ways now available to connect to the internet, not using a totally flexible language like XML could be extremely costly for any ecommerce business.
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Jim Pretin has sinced written about articles on various topics from Insurance, Medicine and Homeopathic Remedies. Jim Pretin is the owner of , a service that helps programmers make email forms.. Jim Pretin's top article generates over 33100 views. to your Favourites.