Templates

See also Graphity Processor resource templates for server-side Linked Data templates.

XSLT

Graphity Client XSLT stylesheets work by transforming raw RDF/XML. Each layout mode is usually produced by transforming RDF result with a group templates for each level of RDF/XML elements, using additional metadata from vocabularies to improve user experience. The default stylesheets are implemented for Jena's RDF/XML layout which groups statements by subject but does not nest:

• /rdf:RDF which represents the RDF model
• /rdf:RDF/rdf:Description resource description which contains properties
• /rdf:RDF/rdf:Description/@rdf:about (subject) resource URI
• /rdf:RDF/rdf:Description/@rdf:nodeID (subject) blank node ID
• /rdf:RDF/rdf:Description/* predicate (e.g. rdf:type) which URI is concat(namespace-uri(), local-name())
• /rdf:RDF/rdf:Description/*/@rdf:resource object resource
• /rdf:RDF/rdf:Description/*/@rdf:nodeID object blank node ID

There are currently following default template modes that should be reused by Graphity applications, if possible:

• rdf:RDF - model and resource level templates found in the master layout stylesheet
  • gc:ReadMode which renders full resource description
  • gc:ListMode renders a list of resources (possibly with descriptions)
  • gc:TableMode renders a table with resources as rows and properties as columns
  • gc:ThumbnailMode renders a gallery of thumbnails
  • gp:ConstructMode which renders an RDF/POST form for creation of new resource
  • gc:EditMode which renders an RDF/POST form for editing of existing resource
• rdf:Description - resource level templates found in the per-vocabulary import stylesheets
  • default one which renders full resource description (by default header and property list)
  • gc:DescriptionMode renders resource description
  • gc:HeaderMode renders resource header (by default with type information)
  • gc:PropertyListMode renders definition list with property names and values (by default grouped by resource types)

The default XSLT 2.0 stylesheets can be found under src/main/webapp/static/org/graphity/client/xsl. The master layout stylesheet imports vocabulary-specific resource-level stylesheets, and XSLT import precedence affects selection of the matching template. They use Bootstrap as the front-end HTML/CSS framework. XSLT keys are used to lookup resource descriptions in the RDF/XML tree, for example key('resources-by-page-of', $absolute-path) where the key definition is:

<xsl:key name="resources-by-page-of" match="*[@rdf:about]" use="gp:pageOf/@rdf:resource"/>

JAX-RS MessageBodyWriter

The transformations are plugged into the application using ModelXSLTWriter which implements JAX-RS MessageBodyWriter and has to be registered as a provider in ApplicationBase. The main stylesheet that gets invoked by ModelXSLTWriter to produce response body (in case (X)HTML is requested) is configurable in web.xml. ModelXSLTWriter passes a number of JAX-RS parameters into the XSLTBuilder, such as $gp:baseUri, $gp:requestUri, $gp:orderBy, $gc:lang, $gc:mode etc.

JAXP URIResolver

DataManager implements URIResolver to resolve known URIs accessed from XSLT into locally cached copies of ontologies that are stored under /src/main/resources/org/graphity/client/vocabulary. Other URIs are ignored by default, but DataManager could be extended so that XSLT would load ontologies and execute queries over HTTP. However, this could dramatically increase transformation time.