XML

[shivani anand]

Why XML is so important? Do I need to know HTML before learning XML?
shivani

[Marius Holm]

XML is only important if you are that much into standardisation and unifying technologies that you think that one platform-independent, universally accessible, programmable format for representation of structured data is of any use.
You don't need to know HTML before you learn XML, but it would have facilitated the learning process. From you asking that way, I assume you don't know any HTML. In that case you should start learning the other way round, XML first and then HTML. HTML is easier and quicker to learn if you don't need to learn XML, but if you will learn XML first, you should start there, and once you got a basic grasp on it...you already know HTML...well almost, you still got to learn the HTML tags, but you already know the syntax better than most web designers...
(Actually, if you can't do that already, it is more important to learn how to ride a motorbike than any of these...)
Regards,
Marius
[This message has been edited by Marius Holm (edited March 13, 2001).]

[Khun Yee Fung]

XML is very important for a lot of reasons. It is like HTML; when people realized they could use HTML to publish pages of pages of information and almost everybody else on the Web can access them, everybody switched to HTML to publish information on the Web. Now, the Web is only one part of Internet. How about the other parts?
Well, XML is meant to be the HTML for a large chunk of the rest of Internet outside the Web, and also to replace HTML eventually as well. So, XML in itself is not important, like HTML in itself is not important. But if everybody is using HTML, you might as well use HTML. Same with XML.
I used to hope that everybody would use ASN.1 because it would save so much time when two applications need to talk to each other. With XML specified, I guess ASN.1 can keep doing whatever it is doing now...
Of course, you don't have to know HTML before you learn XML. In fact, doing it properly, HTML is actually harder than XML.

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Khun Yee Fung
Author of XSLT: Working with XML and HTML

[David Freels]

HTML is used to present content to the user, where XML is used to represent data in a meaningful way. Learning HTML is not needed to learn XML, but it is helpful to know both.
David

[Kevin Yip]

What is ASN.1 as mentioned by Khun Yee Fung?

[Khun Yee Fung]

Oh, ASN.1 stands for "Abstract Syntax Notation Number 1". It is used to specify the format of structured binary data. It has a few "transfer rules" like BER (Basic Transfer Rules) that determine how a chunk of data using ASN.1 can be transferred from one application to another. It is being used right now by LDAP and SNMP to specify their data formats, for instance. Before ASN.1, you could either use ASCII to format data (using base64 or uuencode if you have to), or you use a proprietary format. Both unsatisfactory.
Think about the message format of FTP, which is an example of ASCII message format. Or the message of DNS, which is an exmaple of a binary format.
However, with XML, you can avoid ASN.1 altogether for textual structured data.
Anyhow, a bit offtopic...
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Khun Yee Fung
Author of XSLT: Working with XML and HTML

[shivani anand]

How really parser works? Their are so many parser, which one should I use?
shivai