Re: real time transformations

[Paul Tchistopolskii <paul@xxxxxxx>]

----- Original Message ----- 
From: Lawrence Pit 
To: <xalan-dev@xxxxxxxxxxxxxx>; <xsl-list@xxxxxxxxxxxxxxxx>


> Hi,
> 
> Suppose you are responsible for writing a web application where every page
> is personalized. Target: 1.000.000 customers. Would you dare doing it in
> Java using an architecture where the component developers are outputting XML
> and visual designers writing only XSL?

I doubt 'visual designers' could write complex  XSL stylesheets  ( with 
recursive call-template, for example ). For trivial XSL stylesheets, the 
scenario you describe looks reasonable to  me. What I don't understand 
is what server-side framework are you planning  to use. I guess you'l write 
your own. ( If you think, say,  Cocoon is the solution,  I suggest trying it 
before bulding on top of it ).
 
> The performance of the XSLT tranformations are scaring me to be honest.

I guess you are measuring performance of  Xalan ? Xalan is not 
the fastest  XSLT engine ( I'l say Xalan is the slowest one ). 
http://users.ox.ac.uk/~rahtz/xsltest/Report.html ( but my statement is 
not based on this URL but on some other experience I've  got
with Xalan. Long time ago. ).

To measure  the 'real' performance of XSLT transformation, I suggest
trying  'real'  XSLT engine, like SAXON or XT in 'precompiled stylesheet' 
mode. 

Also please take into account that if your XML components will generate 
not the XML files but the stream of SAX events - you'l also get a performance 
boost.  By the way : stay away from DOM,  if you care about speed.

Also please take into account  that when  you have caching,  the speed of 
particular transformation becomes less important.

There  are actually many other tips and tricks to produce fast  XSL-based 
server-side solution. Consider hiring  experienced contractor. No kidding.

> Using XML/XSL is the future, is what "they" say, 

In fact what "they" really say is "XML/XSL on client side is the future".
They were not thinking about XML/XSL on server at all.

> but I wonder: is this /ever/ going to work in real-time applications?

Not only it can work, but it already works. Can not disclose some more info, 
sorry. 

Because cell-phones ( and other devices ) usually come without built-in 
XSLT engine - I don't think server-side XSL rendering scenario is 
temporary.

Rgds.Paul.



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