Nick Mudge <ma******@hotmail.com> wrote:
I am sorry to be a little off topic here, but can someone describe what XML
is? I know it is programming languague, but what is the deal with it?
Ok, I'll tell you the real truth, the government doesn't want you to
know this but, XML = "Xtraterrestrial Martians are Landing". This whole
angle-bracket stuff is just a government coverup. :-)
Actually, it's not a programming language. You *might* be thinking of
XSLT or DSSL (which aren't really programming languages either, more
like highly complex reporting tools.)
The big hoopla about XML is:
\. Discern content from presentation.
\. Transmit & store complex data structures in a portable manner.
\. Be transformed from one "vocabulary" of XML to another.
\. Give managers and other big-shots zillions of acronyms to use.
It's history is from the SGML world, (it is a subset of SGML) so the
<>'s look familiar. It's kind of cool, and I wonder if PHP was actually
designed with this in mind, but...
<?php ... ?>
Is actually a processing instruction to an XML parser.
There is no "XML Language" really, this is where buzzword galore enters
the picture.
XML is all about angle brackets, namespaces etc.. Imagine HTML.. but...
you get to invent your own tags. Since XML can be transformed, assuming
all the required data is there you can apply XSLT against 1 XML document
to convert it to another XML document where someone else has invented
*their* own tags.
Back in the good ol'e dot.com days when XML was still fairly new, I
worked on an XML search engine (and other XML products) we used to
market XML by saying it "lends context to data" <B>John Henry</B> is
meaningless, but <Name>John Henry</Name> would allow a search tool to
find "Documents with "John Henry" as a name".
In the real world, this won't happen on a large scale any time soon
because everyone has their own idea's about what a <FooBar> should be,
and frankly, going from XML to HTML is kind of a drag when you are
working with multiple <FORM> tags and/or javascript. (XML -> HTML is
wonderful for information *content* though)
Jamie
--
http://www.geniegate.com Custom web programming
User Management Solutions Perl / PHP / Java / UNIX