- From: Giovanni Tummarello <g.tummarello@gmail.com>
- Date: Tue, 27 Apr 2010 23:30:52 +0200
- To: Johan De Smedt <johan.de-smedt@tenforce.com>
- Cc: semantic-web <semantic-web@w3.org>
might be of interest for http://pipes.deri.org there has been quite a bit of work on it.. the GUI produces an XML file which you can then execute with the standalone Jar. cheers Gio On Mon, Apr 26, 2010 at 12:11 AM, Johan De Smedt <johan.de-smedt@tenforce.com> wrote: > Hi, > > When publishing content, XSLT is a key technology. > RDF however is kind of difficult to process with XSLT. > Though there is an RDF/XML serialization, that standard allows for a variety > of ways to express the same things. > > The notes below propose a restricted version of RDF/XML and some usage > conventions. > The objective is to make RDF easily processable by XSLT. > > I am interested in any alternative. > SPARQL result xml is not a full solution because it is limited to ASK and > SELECT queries. > Hence the attached proposal. > > Just like canonical XML, I think this restricted RDF/XML format may be of > interest as a reference in XML processing. > Please let me know if others are interested to discuss this. > > Notes: > Graph representation proposal (restricted RDF/XML usage) > - the result is a list of resources which have properties. > - the id of a resource is an IRI or a CURIE > - all blank nodes are nested within properties. > > <rdf:RDF {namespace}* > -- the namespaces are the ones used in > CURIES/element names > <rdf:Description rdf:about="{subject-uri}"> > <rdf:type rdf:resource="{class-uri}"/> * > ( -- plain literal with optional language > <{data-property-curie} [ xml:lang="{lang-code}" ]> {...value...} > </{data-property-curie}> > or -- xml literal > <{data-property-curie} rdf:parseType="rdf:XMLLiteral" {namespace}* > -- > the namespaces are the ones used in xml-content > {...xml-content.} > </{data-property-curie}>* > or -- typed literal > <{data-property-curie} rdf:datatype="{simple-XML-schema-data-type}"> > {...value...} > </{data-property-curie}>* > or -- expanded blank node > <{object-property-curie} rdf:parseType="Resource"> > <rdf:Description> > . > </rdf:Description> > </{object-property-curie}> > or -- any resource with a known URI > <{object-property-curie} rdf:resource="{uri}"/> > )* > </rdf:Description>* > </rdf:RDF> > > Writing xslt extensions to process RDF on a node by node navigation basis: > - connect to an RDF store and identify a graph > - navigate through the graph by iterating all (or selected) properties of > one or more selected subject resources. > - represent each triple of the iteration result so it is easily processed > by XSLT (with a unique representation). > - allow this property iteration to be nested such that object resource can > be visited recursively. > Proposal for result representation (see above) > > 1) connecting to an RDF store + graph(s) for access > > 2) To get statements from this store and to merge the RDF into XML, > something like > <xsl:variable name="rdfresult" > select="readrdf:for-each-property($subjects,$namespaces,$filter)"/> > Where: > namespaces="{alias uri}*" -- namespaces used in subjects and > filter > subjects="{subject-uri}+" > filter="{property-curie}*" -- empty filter or no filter => give > all properties > > 3) Process the result based on xml nodes (see next page) as follows > 3.1) typical processing : > <xsl:for-each > select="$rdfresult/rdf:RDF/rdf:Description[@rdf:about='{subject-uri}']/*..." >> > <xsl:variable name="current-property" select="name()"/> > . do other stuff > </xsl:for-each> > 3.2) recursive processing : > <xsl:for-each > select="$rdfresult/rdf:RDF/rdf:Description[@rdf:about='{subject-uri}']/*[@rd > f:resource]"> > <xsl:variable name="current-property" select="name()"/> > <xsl:variable name="current-uri" select="@rdf:resource"/> > . recursively process as from step 2 using $current-uri as > he (new) subject-uri ... > </xsl:for-each> > > Kind Regards, > Johan De Smedt (CTO TenForce) > ======================= > mail: johan.de-smedt@tenforce.com > mobile: +32 477 475934 > > > > >
Received on Tuesday, 27 April 2010 21:31:26 UTC