RE: HTML to XML, vice versa -- JAVA400-L

Thanks for the offer, Fred.  

Would some small code snippets be easy to show?  Even if they don't deal
with html or xml, just something to show how a factory or decorator class
works.  This is where I'm having a hard time understanding how it would
work.

I get this much... that a table has a table header (<table>) and a table
trailer (</table>).  

What I don't understand is how at runtime you're going to "plug in either an
HTML factory or an XML factory".  Why this is confusing is because XML
doesn't contain "tables" per say.  I'm also having a hard time understanding
how this is "plugged in" as to me it seems reasonable that there has to be
something somewhere, a switch, an atrributre, or something to "tell" it
which factory to use.  

The terminology of "factory" and "decorator" class is also new to me.  My
idea of these is that the factory is what produces the final product (ie
HTML or XML tags).  But, what does the decorator class do, and how is it
invoked?  That's why seeing some simple examples would help my procedural
mind grow.  :)  

Thanks again!  This should make some good archive info!

Brad

> -----Original Message-----
> From: Fred Kulack [mailto:kulack@us.ibm.com]
> Sent: Tuesday, March 06, 2001 2:11 PM
> To: JAVA400-L@midrange.com
> Subject: Re: HTML to XML, vice versa
> 
> 
> 
> On 03/06/2001 at 01:29:23 PM, owner-java400-l@midrange.com wrote:
> I can do it easily because I use a decorator class that in turn uses a
> factory class.  To do this, I break down the data stream into 
> something
> abstract:
> 
> A "table" has a "table header" and a "table trailer", and 
> between those has
> 0-N "tablerows"
> 
> A "tablerow" has a "tablerow header" and a "tablerow 
> trailer", and between
> those, has 0-n "tablecells"
> 
> A "tablecell" has a "tablecell header" and a "tablecell trailer", and
> between those has element data
> 
> The decorator class invokes methods from the factory 
> interface to get the
> value of, for instance, a "tablecell header".  At runtime I 
> plug in either
> an HTML factory or an XML factory.  The HTML factory returns 
> "<td>", while
> the XML factory would return "<datatag>".
> -- end of excerpt --
> 
> I'd just like to add for Java/OO rookies out there:
>   Read the above again and understand it. If you
>   don't, ask questions about it.
>   It will REALLY help you.
> 
> It's a fundamental wonder of OO development: Polymorphism.
> 
> You don't know if you're doing XML or HTML and you
> DON'T CARE. All you have is this decorator object that
> come from somewhere and it does its thing.
> 
> 
> 
> "The stuff we call "software" is not like anything that human society
>   is used to thinking about. Software is something like a machine, and
>   something like mathematics, and something like language, and
>   something like thought, and art, and information...
>   but software is not in fact any of those other things."
> Bruce Sterling - The Hacker Crackdown
> 
> Fred A. Kulack  -  AS/400e  Java and Java DB2 access, Jdbc, 
> JTA, etc...
> IBM in Rochester, MN  (Phone: 507.253.5982   T/L 553-5982)
> mailto:kulack@us.ibm.com   Personal: mailto:kulack@bresnanlink.net
> AOL Instant Messenger: Home:FKulack  Work:FKulackWrk
> 
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