Task 9: What is wrong with XML? Illustrate your responses with examples

 XML (Extensible Markup Language) is a general-purpose specification for creating custom markup languages. The term extensible is used to indicate that a markup-language designer has significant freedom in the choice of markup elements. XML's goals emphasize representing documents with simplicity, generality, and usability over the Internet. XML has been used as the basis for a large number (at least hundreds) of custom-designed languages. Some of these, for example RSS, Atom, and XHTML, have become widely used on the Internet. XML dialects (often packaged in archive files) are becoming the default file format for office-productivity software packages, including Microsoft Office, OpenOffice.org, AbiWord, and Apple's iWork. Lets discuss advantages and disadvantages of XML.

During my Research I stumbled on a article that (Scientific American) clearly states what XML developers mean when they talk about the ability to use different types of document types. A doctor can e-mail an HTML document featuring a patient's medical records, but that does not mean much to the nurse receiving them who has to enter them into a database. The database would read the document, as the article says, as "<H1>blah blah blah<H1>", for example. With XML, the information can be organized into recognizable and totally subjective fields that can be more easily read by a database.

Also, when you submit a query to an online bookstore, you are not waiting for the price information. You are simply waiting for the stylistic presentation of some text, which could happen to be price information. This is how HTML does it; the flexibility of XML is supposed to deliver and understand (by way of organization) the actual material (i.e., the price). Furthermore, a surfer would then be able to search for prices. Since HTML does not have any delimiter for prices (while XML does, or rather, can), searches just return the word "price", which could be used in many other connotations, or irrelevant numbers.

When the article refers to the "World Wide Wait", it speaks of the amount of time that it takes for your query to get to the server and then back to you. This time is spent mainly on displaying the information, and not the information itself, and the article calls it a waste of time, which I agree with. After all, the Internet's first priority when it was designed was to transmit information, not present it. (Of course, a visually pleasing format is nice and adds a lot of the fun to web design; XML does not eliminate this capability.) XML would be able to implement another program that could compute the information specific to that document and then return it to you on the spot. There would be no need to involve the server, hence removing the "wait". 

It is a lot more difficult to find documented disadvantages about XML; most information returned from searches are pages devoted to XML and are therefore singing its praises. John E. Simpson in fact states that software vendors are likely to explain that elements are not bugs, but rather a feature. One is more likely to hear about its disadvantages on the relatively personal pages, the people attempting to use XML, and those generally involve disadvantages that would bother an experienced XML user, and would mean nothing to someone attempting to understand the language. However, Simpson talks about some of these disadvantages pretty clearly in his xml.com question/answer session.

 
He discusses how XML can be seriously verbose, because of the specificity needed. While XML speeds up the transmitting of actual information, it also requires a lot of mark-up to be transmitted as well, and often the mark-up can outweigh the content. He also describes how XML is platform-neutral. This seems to be a "not a bug, but a feature" situation. This neutrality is what allows XML to be so flexible, to allow so many different types of information to be used by so many different types of media. But no one browser or application can understand 100% of its information. 

In my view, I feel that XML's main disadvantage is that, like almost any new, supposedly world-changing idea, there is a lot of hype involved. Most personal pages talk about this concept. It is not going to save the world, and in a narrower sense, nor will it solve all Internet data-related problems. It seems to me that the W3C's conversion from HTML to XHTML is a little quick; the average user is probably still adapting to HTML 4.0, and the game's rules are about to change completely. Of course, XHTML is designed to ease XML into widespread use of the Internet, but I don't know anyone who actually really knows how to use it yet. Also, it seems to me that the browsers have more say about what will be widespread and mainstream the W3C does; if the monolithic browsers (by which I mean, surprisingly, Netscape and IE) can't display it, what is the sense in using it? 

Everybody should take this new XML thing one step at a time. It seems to actually be quite simple to use, but that realization was only come to after a whole lot of digging. The W3C must remember that a large percentage of "web designers" (using the broadest sense of that description - those who design web pages) are not computer experts who have been waiting for XML's breakthrough for a long time. They are people who understand HTML and are now faced with a new language. 

However, XML has a lot of potential, and while I don't agree with a lot of the XML experts who say it is nearly as easy to use as HTML, it is by no means impossible for a casual web designer to learn. And the added difficulty is in fact more than compensated by the added power. I think the experts talk more about its ease of use in relation to the extremely complicated SGML, rather than in relation to HTML. And I totally agree that XML will allow Internet-transmitted documents to serve more functional purposes; having a web page that does not necessarily have to interact with a server but can interact with a database system is no mean feat. So once people get over the difficulty of learning XML, it appears that the ease pops up later, as they apply the language they have come to understand. 

Below are the XML Disadvantages in Views 

·         Enforcement of typing is not strong enough

·         Too flexible

·         Disagreement in the meaning of tags 

·         Comlicated XMl files with many constraints are hard to construct manually

·         Verbose

      XML syntax is redundant or large relative to binary representations of similar data.

The redundancy may affect application efficiency through higher storage, transmission and processing costs. 

      

      XML syntax is verbose relative to other alternative 'text-based' data transmission formats.

No intrinsic data type support: XML provides no specific notion of "integer", "string", "boolean", "date", and so on.

       

       Reference: http://www.theukwebdesigncompany.com/articles/xml-advantages-disadvantages.php[Accessed 20/01/2011]