[Opensource] xsl handling: make it like JSP handling?

[Michael Rimov]

At 03:51 PM 5/9/2003 -0700, larry hamel wrote:

>I like the idea of encapsulating the code in XMLViewHandler.java, but in 
>your counter-proposal, there is a large discrepancy between forwards of 
>JSP type and forwards of the proposed xsl type. In other words, if 
>Expresso documents and current practices all describe forwards like
>
>         <forward name="displayItem" 
> path="/jsp/groupAction/displayItem.jsp"/>
>
>then it would be natural to misunderstand a forward like
>
>         <forward name="rootTree" 
> path="/servlet/XMLViewHandler/xsl/rootTree.xsl"/>
>
>and it would require referring to documentation. In contrast, the original 
>proposal makes .xsl files roughly equivalent to .jsp files at least for 
>configuration purposes:
>
>         <forward name="displayItem" 
> path="/jsp/groupAction/displayItem.jsp"/>
>         <forward name="rootTree" path="/xsl/rootTree.xsl"/>

Ok, fair enough... I'm with you so far.

>Consider that there are many examples of mimetype extensions being used 
>for parsing purposes. JavaBeans use this with the JAF. I think Expresso 
>will add a lot by parsing for a .xsl extension and handling it appropriately.
>One alternative would be to use something like
>
>         <forward name="rootTree" path="xml?xsl=/xsl/rootTree.xsl"/>
>
>which makes it a little more obvious that something is going on, and even 
>offers a way to add arbitrary parameters. But recognizing .xsl extension 
>just seems nicer to me.

Yes, and this looks awful :)  [As does 
/servlet/XmlViewHandler?xsl=blah]  So let's scrap this train of thought....


>One thing I can encapsulate is the file path elaboration. Instead of doing 
>that in the controller, it can be placed into XMLViewHandler.java, so that 
>the processing code in Controller.java becomes:
>
>// xsl processing
>if (fwd != null) {
>         String path = fwd.getPath();
>         if (path != null && path.endsWith(".xsl")) {
>                 fwd = mapping.findForward("xml");
>                 req.setParameter("xsl", path);
>         }
>}

Great.  Can you refactor this code into a "getActionForward()" or something 
like this in the Controller code?  Then we can easily refactor the code to 
add multiple forward types, without cluttering up the main flow of control. 
[Consider velocity template names, Cocoon server pages, etc].

Also, minor quibble, can you check for .xsl and .xslt?  I always use xslt 
in my own development. :)  In fact, you might want to get the final file 
extension so we can case insensitive compare it for all our Windows 
developers.  [I sure make things complicated, don't I? ;) ]



>while the path manipulation moves to XMLViewHandler.java and becomes
>
>                 // determine whether the xsl path is relative
>                 File xslFile = new File(xsltName);
>                 if (!xslFile.exists()) {
>                     xslFile = new File(mRootPath, xsltName);
>                     if (!xslFile.exists()) {
>                         log.error("cannot find xsl file: " + xsltName);
>                     }
>                 }
>
>can you live with that?

Fair enough!!  +1 from me.  I'm all for making other rendering format first 
class citizens in Expresso!

Thanks for the improvement thoughts!!

                                                 -Mike