Hello!

Where's the best place to influence the sorting of results returned by
the fresnel engine? Is it possible to use the SPARQL "ORDER BY"
functionality through fresnel? I'd like to avoid writing comparators for
the search results and do this after retrieving the results.

I guess FRESNEL is not responsible for that, since sorting concerns the
structure of the results as a whole and not the display of a single
instance. On the other hand the engine is passed the whole data
repository and then performs the selection, so maybe it should also sort
it. Is it the only way to go to sort afterwards, or am I missing
something. I hope so, since at least in longwell I cant find any
xsl:sort expressions. Do I have to pass an already sorted data
repository to the engine? How could I do that?

I tried specifying an order with fresnel using a SPARQL selector for the 
sorting, but this doesn't return any results. Does the fresnel engine 
support SPARQL selectors and, if yes, is the syntax below correct? I 
couldn't find the equivalent for fresnel:fslselector for sparql in the 
docs in the section 1.3.3 SPARQL Selectors at 
http://www.w3.org/2005/04/fresnel-info/manual/ . However 
fresnel:sparqlSelector seems to be right, since fresnel:sparqlselector 
returns a NullPointerException and fresnel:sparqlSelector doesn't)

:eventLens rdf:type fresnel:Lens ;
        fresnel:purpose fresnel:defaultLens ;
        # this works and selects events:
        fresnel:classLensDomain hist:Event;
        # this works either
        #fresnel:instanceLensDomain "hist:Event"^^fresnel:fslSelector ;
        # this doesn't work (No lenses matching the data found.):
        fresnel:instanceLensDomain "SELECT ?event WHERE {?event rdf:type 
hist:Event ; rdfs:label ?label } ORDER BY 
(?label)"^^fresnel:sparqlSelector ;

Does FSL support sorting? I couldn't find a note on that in the 
documentation at least.

Thanks for any comments on that!


Regards
Jan

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