CS30121

2 Introduction to XML - What is XML? Extensible Markup Language, or XML for short, is a new technology for web applications. XML is a World Wide Web Consortium ( standard that lets you create your own tags. XML simplifies business-to-business transactions on the web

CS30123 Why Do We Need XML? Why do we need XML when everyone's browser supports HTML today? To answer this question, look at the sample HTML Code shown. HTML tags are for browsing; they're meant for interactions between humans and computers.

CS30124 Rendering HTML When rendered, the HTML in the previous example looks like this. As you can see, HTML tags describe how something should render. They don't contain any information about what the data is, they only describe how it should look.

CS30125 Sample XML Code Now let's look at some sample XML Code. With XML, you can understand the meaning of the tags. More importantly, a computer can understand them as well. It's easier for a computer to understand that the tag is a zip code.

CS30126 Rendering XML XML from the previous example might be rendered like this. Notice that even though the tags are different, they can still be rendered just like HTML.

CS30127 A Second Rendering of XML By applying a different stylesheet to the same document, an XML document can be rendered in different formats. The key is that with XML the information is in the document, while the rendering instructions are elsewhere. In other words, content and presentation are separate.

CS30128 How XML Will Change the Web ?

CS30129 Enable universal data If you look at the Web today, you'll find several universal technologies, including TCP/IP, HTML. TCP/IP is the universal connectivity protocol; everything from mainframes to laptops to cellular phones can connect to the Web using it. HTML is the universal rendering language. Although not all browsers support all functions, there is a core set of HTML tags that can be rendered on any browser.

CS Enable universal data Because of these ubiquitous technologies, it's relatively straightforward to create a Web application that runs on any platform. XML completes the picture by enabling universal data. You can build an XML document that describes a data structure, and that structured data can be sent anywhere across the Web. XML will change the Web because of its power and flexibility as a data interchange format.

CS Enable Business to Business Communication

CS Enable Business to Business Communication When using XML, I can receive XML-tagged data from your system, and you can receive XML-tagged data from mine. Neither of us has to know how the other's system is organized. If another partner or supplier teams up with my organization, I don't have to write code to exchange data with their system. I simply require them to follow the document rules defined in the Data Type Definition (DTD).

CS Enable Smart Agents An agent,is a piece of software that interprets data and performs a task using that data. A good agent interprets information intelligently, then responds to it accordingly. If the data sent to an agent is structured with XML, it's much easier for the agent to understand exactly what the data means and how it relates to other pieces of data it may already know.

CS Enable smart searches A major problem with today's Web is that search engines can't process HTML intelligently. For example, if you're searching for someone named Chip, you might get pages for chocolate chip cookies, RAM chips, poker chips, and guys named Chip. On the other hand, if you were searching for documents that contained a tag with a value of "Chip," you would get much better results. Being able to limit searches to those XML documents that use a certain set of tags would allow you to weed out a massive amount of unrelated content.

CS Enable smart searches As an aside, being able to limit search results to documents that use a particular tag set is one of the market forces that will drive the acceptance of XML. Say that a group of car dealers defines a tag set for used cars, and that several popular search engines promise great results because their search engines look only at XML documents using those tags. If you're an auto dealer, you can either join the market and support that tag set or be left out of the market completely. If your inventory is not described using the standard XML markup, would-be car buyers using an XML search engine will never find you.

CS The promise of XML XML is poised to change the Web, enabling a whole new generation of e-business applications. Just as HTML and graphical browsers sparked an exponential growth in Web use, XML's enhancements to e-business will start another period of exponential growth.