Re: [Exist-open] MVC pipelining XSLT -> XSLFO

[Hungerburg <pc...@my...>]

Am 2011-10-28 15:27, schrieb Hungerburg:
> Hopefully this problem finds some interest:
>
> Can a self sufficient controller be taught to have a request for
> /foo/bar.png return /foo/bar.svg served as a png?
>
> I tried to make this a two forwards in a view dispatch:
> 1 use the xslt servlet to transform svg to FO,
> 2 use the xquery servlet to render the result in png,
> but dont know how to store/retrieve the intermediate FO.
>
> The <set-attribute name="xquery.attribute" value="model"/> approach just
> doesnt work out for me.

I have this now somehow working: Enlightenment started with this 
sentence from docs: "XQueryURLRewrite passes the HTTP response stream of 
the previous servlet to the HTTP request received by the next servlet."

BUT, I cannot just write my xquery below the forward to XQueryServlet in 
controller.xql; Instead I have to write it into a variable, and pass 
that as a string literal through "source". (Otherwise it would always 
fail because it cannot find the xquery in the original request path.)

Code below:

> let $query:= 'xquery version "1.0";
>     let $foparams :=
>         <parameters>
>             <param name="FOPauthor" value="Me"/>
>             <param name="FOPtitle" value="Skizze"/>
>             <param name="FOPkeywords" value="Skizze KW"/>
>             <param name="FOPdpi" value="96"/>
>         </parameters>
>     return
>     response:stream-binary(
>         xslfo:render(
>             request:get-data(),
>             "image/png",
>             $foparams,
>             ()),
>         "image/png",
>         "")'
>
> […]
> else if ($parts[4] eq 'png') then
>     <dispatch xmlns="http://exist.sourceforge.net/NS/exist">
>         <forward url="{$svgd}"/>
>         <view>
>             <forward servlet="XSLTServlet">
>               <set-attribute name="xslt.stylesheet"value="{concat($view, 'foSKIZZE.xsl')}"/>
>               <set-attribute name="xslt.output.omit-xml-declaration"value="yes"/>
>               <set-attribute name="xslt.output.indent" value="yes"/>
>               <set-attribute name="xslt.output.media-type"value="application/xml"/>
>               <set-attribute name="xslt.output.method" value="xml"/>
>             </forward>
>             <forward servlet="XQueryServlet">
>                 <set-attribute name="xquery.source" value="{$query}"/>
>             </forward>
>         </view>
>         <cache-control cache="no"/>
>     </dispatch>

There are three redirects:

1)
 From the controller path (...png) to the path of the svg (xmldb...svg)
2)
The xsl transform of SVG to FO
3)
The xquery to render the POST data to PNG

-- 
Peter