RE: [WEB400] XML/XSL

["Bartell, Aaron L. (TC)" <ALBartell@xxxxxxxxxxxxxx>]

<Nathan>
XSL is interesting, but how did they come up with the term "style sheets"
for XSL?  Traditionally, style sheets simply associate color, font, and
similar attributes to HTML elements.  In this context, isn't "style sheet"
really a misnomer for XSL?
</Nathan>

I am guessing because potentially you could take any number of XML feeds and
translate them into one look and feel with XSL.  

Addressing your other concerns over the amount of XML steps.  I think this
is becoming par for the course when you need to communicate a bunch of
different ways and you don't always know what is going to be on the
receiving end of your program.  And if that is the case, what else are you
going to use, comma separated values?  XML is a good thing because it is
graying the lines of systems that couldn't communicate well, but it has
upped the processing needs as you have stated which isn't good.  So once
again Intel will continue to build faster processors only to have the next
Java or XML language come out that will most definitely put us back to
-1000% speeds of RPG.  

Although, if you look closely at how RPG is evolving you will notice that it
is also slowing down with the advent of longer fields and then the BIF's
that need to operate on those fields.  I hear that dynamic arrays are coming
V5R3, and that will probably slow it down, but it will also get us a much
needed enhancement that RPG has needed for a long time.

Just some thoughts,
Aaron Bartell   

-----Original Message-----
From: Nathan M. Andelin [mailto:nandelin@xxxxxxxxxxxxxxxxxxx]
Sent: Friday, August 29, 2003 12:15 PM
To: 'Web Enabling the AS400 / iSeries'
Subject: Re: [WEB400] XML/XSL


XSL is interesting, but how did they come up with the term "style sheets"
for XSL?  Traditionally, style sheets simply associate color, font, and
similar attributes to HTML elements.  In this context, isn't "style sheet"
really a misnomer for XSL?

Isn't XSL really a programming language with looping constructs, conditional
logic, and so forth?  Well, such is the case with object oriented
vocabulary, which sadly tends to get more convoluted over time.

I think XSL was conceived as a way to move program logic to the workstation
where HTML generation could be performed by a dedicated processor, enhancing
overall throughput.  It's interesting to see the transformations moved back
to the server.

Consider that servlets or JSPs typically transform SQL result sets to XML,
then another program (XSL) is evoked to transform the XML into HTML.

I can envision the Transformer Factory parsing and interpreting the program
source code (XSL) as well as parsing the formatted data (XML) to finally
generate the HTML.  Why not bypass the SQL to XML transformation step
altogether?

Consider the overhead of loading an additional program interpreter
(Transformer Factory) as well as the relatively poor performance of
interpretive runtime environments generally.  It must be things like this
that give Java its reputation for poor performance.

I recently stress tested a simple servlet that generated HTML from an SQL
result set, and compared it to the performance of a RPG program that
generated the same HTML from the same data file.  The RPG program provided
1000% to 1300% better performance.  If another step were added to the
servlet to generate XML from the SQL result set, then generate HTML from the
XML, I can only imagine the additional performance hit.

Just a consideration.

Nathan M. Andelin
www.relational-data.com


----- Original Message -----
From: "Bartell, Aaron L. (TC)" <ALBartell@xxxxxxxxxxxxxx>
To: "'Web Enabling the AS400 / iSeries'" <web400@xxxxxxxxxxxx>
Sent: Friday, August 29, 2003 9:15 AM
Subject: RE: [WEB400] XML/XSL


> I would not rely on the browser to do the transformation unless you can
> control the version of browser used.  Yes you can do the transformation on
> the iSeries in languages that support it such as Java.  Here is an
example:
>
>
> TransformerFactory tFactory = TransformerFactory.newInstance();
>
> Source xmlSource = new SAXSource(new InputSource(new
> StringReader(readIFSFile(in))));
>
> Source xslSource = new StreamSource(new
> java.net.URL("http://mycompany.com/Email.xsl";).openStream());
>
> Transformer transformer = tFactory.newTransformer(new StreamSource(new
>
java.net.URL("http://icsm400.taylorcorp.com/EmailError.xsl";).openStream()));
>
> transformer.transform(xmlSource, new StreamResult(System.out));
>
>
> If you apply the style sheet programmatically then you can use style
sheets
> that reside anywhere.  If you apply stylesheets by imbedding it in the XML
> document then the style sheet must reside on the same machine that the
> request was done.
>
> Hope that helps,
> Aaron Bartell


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