Making Your Own
Okay, say you want to create a
document where a certain type of text is going to be bold, italic,
red, 25 point, Arial font, and a few other fancy things. And this
type of text appears a great many times. In HTML you would need to
write out the start and end flags every time you made the text. Or,
you might say, you can set up a style sheet to do that. Well, that's
the general idea here. You set up a giant style sheet-type document
that acts as "mother" for all the other documents. So, what's the
difference? Well, style sheets work inside of HTML documents. You
have to create one to use the other. Creating your own DTD
eliminates one whole step in the process -- the HTML.
|Okay, fine... but what is XML?
XML is a simplified
version of SGML intended to allow people like you and me a
pretty good shot at learning it. SGML is wide open. It is a
10,000-piece jigsaw puzzle with double-sided pieces spread all
over the floor. XML is the same jigsaw puzzle with big
sections already put together.
So, What's Wrong
My personal opinion is that nothing
is wrong with it. It was the first computer language that could be
understood and used by the masses. It gave the Web to the common
person. But those in the XML know claim HTML is clunky. They say
it's become static. There's not a lot more one can do with it.
Supposedly XML will allow a lot more flexibility in your Web pages.
There will also be more flexibility in your HREF links. You'll be
able to create cross-references and threads and other fun stuff. At
least that's what the brochure says.
HTML is not dead, nor is it
breathing funny. HTML will be around for years to come, if not
forever. It is still a solid format and too many people know it. I
believe I will be able write HTML and post Web pages as long as I
live using HTML alone. They just might not be as fancy as other
Two Kinds of XML
The two main types of XML pages are
the "standalone" and those that use a DTD. The standalone is just
what it says: the page stands alone relying on the browser to have
the XML DTD. In the XML language, the browser will be the XML
processor. The other type of page offers the DTD to the browser so
it can run the page.
The standalone can be created by
simply making some alterations to your current HTML document:
- Lose the current declaration statement and replace it with
<?XML version="1.0" standalone=
"yes"?>< /FONT>< /FONT>
- Remember that XML IS
CASE SENSITIVE. If you use caps to start the command, use caps to
end the command.
- This format of caps or
no caps must continue fully throughout the document. If you use
IMG first, you must continue to capitalize it the rest of the way
through or the XML DTD will see it as two different commands.
- All tags that do not
require end tags (like <IMG> or <P>) must now be given
- All tags that did not
require an end tag must also be given a slash before the final
so: <IMG SRC= "pic.jpg"/></IMG><
- Each subcommand must be
surrounded by quotes. (Like: TEXT="brown"</FONT>)<
- Lose all & command
and ASCII code characters.
- Make sure you are
running the page in a browser that supports XML.
If you have followed all
these rules, then you have created a document that is termed
"well-formed." That means it will run. You see, XML is nowhere near
as forgiving as HTML.
As I said above, the second type of
page is the one that uses a DTD. Now, in XML, you'll need to set up
your own DTD items (which are called "entities" in the business).
Each entity will allow you to create your own tag in a traditional
HTML format. Entities themselves do nothing. They simply block off
sections of the page. Any text that happens to be captured inside of
that space will then be affected by the parameters assigned to the
entity. Sound familiar? HTML works the same way. For example, say
you wanted to create the tag <SUPER> that would make text red
and underlined. (As far as I know that one doesn't exist in HTML.)
This would be the basic format: (Please understand it is a bit
more than this, I am just trying to stay basic at first to keep us
all on the same page.)
Yupper! In fact there's much more. I don't
know how goofy into this stuff you are, but if this is your bag, XML
certainly offers some enjoyable reading before bed. There isn't a
lot written on the subject (I mean in a relative fashion, like when
compared to the number of pages available on the music group
Hanson), but what is written is very thick and very technical. It
takes some plowing through, but you'll start to see it all come
together after spending the time.
Now it's up to you to
decide if XML is for you. I have had limited contact with the
language because I am more of a Web site designer than production
tech. If you're getting into database management and/or cross-page
abilities, maybe you should give it a try. If you're simply
attempting to make a nice Web site, maybe it will be a bit over your
head. You have to decide.
In late 2000, Earthweb
(now DICE.com) decided to go to a fully XML format. Many sites
melded to the format well and ran smoothly. HTML Goodies was a
different story. I've set the site up in a hierarchy format and it
just wouldn't fit neatly into XML. Every time we tried to take it
live, the number of errors forced us to go back to the HTML format.
It was such a pain, in fact, that we decided to scrap the XML
version altogether. That didn't sit real well with those who put
their hearts and souls into the new site.