Re: [xsl] Transforming XML 'on-the-fly' / Dynamic XSLT???

["M. David Peterson" <m.david@xxxxxxxxxx>]

Nick,

Joseph Dane brought up a good example of how to implement a solution 
from within Java that allows you the ability to do "mini" transforms of 
data which can then be passed to another transformation process based on 
the results of each transformation or upon the variables that you are 
speaking of.  Without seeing an example of the variables I can't give 
you an example of the Java code beyond pointing you to Dr. Kays company 
site (http://www.saxonica.com) to download the latest Saxon bits which 
come packaged with tons of Java examples that implement all sorts of 
transformations using various streams (dynamic and static) and document 
types (DOM, SAX, etc...)...  I would pay specific attention to the TrAX 
examples (part of the JAXP API) as this will get you more inline with 
what Joseph is refering to.

Adding to this a bit you might also want to consider the idea of 
creating a generic XSLT stylesheet that simply acts as a mechanism for 
matching one set of input XML patterns to another set of output XML 
patterns.  In essence you will be creating an XML output definition file 
that can be mapped to the input file and then used to weave together any 
data elements necessary to give the proper output you desire.  This 
gives you much more freedom and is more inline with what XSLT was 
designed for in the first place... a way to locate patterns in your XML 
data and then output a specified pattern of data once that pattern has 
been matched w/o hardcoding your stylesheets in a way that makes them 
harder to reuse for other types of output.  Data weaving is not a new 
concept by any stretch of the imagination but its something that hasn't 
seen a lot of airtime as it can sometimes be a little tricky getting 
things to work just as you want them to.  Best rest assured that just 
like XSLT, once you get it you get it and life becomes that much easier 
and your coding that much more productice than before.

An example of this type of transformation process can be found at 
http://www.aspectxml.org.  This takes the weaving concept and applies it 
to the Aspect Oriented Software Development paradigm but it should 
adequately showcase the concept that I am speaking of and give you some 
ideas on how to implement this concept into your own solution.

If any of this is helpful and you still have further questions don't 
hesitate to ask.

Best regards,

<M:D/>



Nick Roberts wrote:

> Hi all,
>
> I'm currently investigating into a JAVA based application aimed to 
> transform an XML document.
>
> I understand XSLT and how it is used to transform XML pages, however, 
> my current understanding is that an XSLT page has to be pre-written, 
> with a pre-definition of how you want to transform the XML document.
>
> What I want to achieve is some kind of tool, which will input an XML 
> document, then transform this document based on arguments declared 
> within the application. For example, once the XML document has been 
> inputted into the system, you can view the current nodes and then say 
> how you want to transform these.
>
> As far as i'm aware, this would require some kind of method of 
> 'dynamically' creating an XSLT page, without any kind of 
> pre-definition of how the XML documents' required to change.
>
> Sorry if i'm not explaining myself very well but I hope you can 
> understand what i'm trying to achieve.
>
> Thanks in advance,
>
> Nick
>
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