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How We Use Epimorphics Linked Data API (ELDA) in Costal and Marine Spatial Planning Vocabulary project. Linyun Fu 2013-03-06. Linked Data API. ELDA Stands for Epimorphics Linked Data API Java open-source implementation
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How We Use Epimorphics Linked Data API (ELDA) in Costal and Marine Spatial Planning Vocabulary project Linyun Fu 2013-03-06
Linked Data API • ELDA Stands for Epimorphics Linked Data API • Java open-source implementation • Linked Data API Specification: http://code.google.com/p/linked-data-api/wiki/Specification • http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocabs • http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims • http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/term/0008 • http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/terms • http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/term/0008/narrower
ELDA • Linked data API introduction by Epimorphics Ltd.: http://www.epimorphics.com/web/projects/linked-data-api • Downloadable from http://code.google.com/p/elda/downloads/list • java -jar elda-VERSION.jar • Quick start doc: http://elda.googlecode.com/hg/deliver-elda/src/main/webapp/lda-assets/docs/E1.2.19-index.html • Installing CMSPV Vocabulary Service: http://tw.rpi.edu/web/project/CMSPV/InstallingVocabularyService
Next steps • Identifying an endpoint • Binding variables • Selecting resources • Viewing resources • Formatting graphs • All done with spec files
Spec files • samplespec file: https://scm.escience.rpi.edu/svn/public/projects/cmspv/branches/elda/specs/cmspv.spec.ttl • in /{path/to}/Elda_standalone_{version}/webapps/elda/WEB-INF/web.xml: <servlet> <servlet-name>loader-init</servlet-name> <servlet-class>com.epimorphics.lda.routing.Loader</servlet-class> <init-param> <param-name>com.epimorphics.api.initialSpecFile</param-name> <param-value>cmspv::specs/cmspv.spec.ttl </param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet>
Identifying an endpoint spec:api a api:API; ... api:sparqlEndpoint <http://localhost:3030/cmspv/query>; #api:sparqlEndpoint <local:data/example-data.ttl> api:base "http://aquarius.tw.rpi.edu:8047/elda/cmspv"; ... api:variable [api:name "base"; api:value "http://cmspv.tw.rpi.edu/rdf"], ...
Binding variables spec:api a api:API; ... api:sparqlEndpoint <http://localhost:3030/cmspv/query>; #api:sparqlEndpoint <local:data/example-data.ttl> api:base "http://aquarius.tw.rpi.edu:8047/elda/cmspv"; ... api:variable [api:name "base"; api:value "http://cmspv.tw.rpi.edu/rdf"], ...
Selecting resources spec:vocabulariesEndpoint a api:ListEndpoint; api:uriTemplate "/vocabs"; api:exampleRequestPath "/vocabs"; api:selector [ api:where "?item rdf:typeskos:ConceptScheme. ?item skos:prefLabel ?label."; api:orderBy "?label"; ]; . http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocabs api:base is "http://aquarius.tw.rpi.edu:8047/elda/cmspv"
More examples spec:vocabularyEndpoint a api:ItemEndpoint; api:uriTemplate "/vocab/{vocabulary}"; api:itemTemplate "{base}/vocab/{vocabulary}"; api:exampleRequestPath "/vocab/nims"; . http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims shows resource: http://cmspv.tw.rpi.edu/rdf/vocab/nims {base} = http://cmspv.tw.rpi.edu/rdf; {vocabulary} = nims
spec:termEndpoint a api:ItemEndpoint; api:uriTemplate "/vocab/{vocabulary}/term/{term}"; api:itemTemplate "{base}/vocab/{vocabulary}/term/{term}"; api:exampleRequestPath "/vocab/nims/term/0008"; . http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/term/0008
spec:vocabularyTermsEndpoint a api:ListEndpoint; rdfs:comment "I am making an assumption that I can easily map the scheme URI based on the Linked Data URI"; api:uriTemplate "/vocab/{vocabulary}/terms"; api:exampleRequestPath "/vocab/nims/terms"; api:variable [ api:name "scheme"; api:value "{base}/vocab/{vocabulary}"; api:typerdfs:Resource; ] ; api:selector [ api:where "?item skos:inScheme?scheme. ?item skos:prefLabel ?label."; api:orderBy "?label"; ] ; . http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/terms
spec:NarrowerTermsEndpoint a api:ListEndpoint; api:uriTemplate "/vocab/{vocabulary}/term/{term}/narrower"; api:exampleRequestPath "/vocab/nims/term/0008/narrower"; api:variable [ api:name "concept"; api:value "{base}/vocab/{vocabulary}/term/{term}"; api:typerdfs:Resource; ] ; api:selector [ api:where "?conceptskos:narrower ?item. ?item skos:prefLabel ?label."; api:orderBy "?label"; ] ; . http://aquarius.tw.rpi.edu:8047/elda/cmspv/vocab/nims/term/0008/narrower
Viewing resources, formatting graphs spec:SKOSViewer a api:Viewer; api:name "SKOS Viewer"; api:includeapi:labelledDescribeViewer; extras:describeAllLabelskos:prefLabel; . spec:htmlFormatter a api:XsltFormatter; api:name "html"; api:mimeType "text/html; charset=utf-8"; api:stylesheet "lda-assets/xslt/cmspv.xsl"; .
A broader chain viewer spec:broaderChainViewer a api:Viewer; api:name "Broader Chain Viewer"; api:includeapi:describeViewer; api:properties "prefLabel, broader.prefLabel, broader.broader.prefLabel, broader.broader.broader.prefLabel" . … spec:broaderChainEndpoint a api:ItemEndpoint; api:uriTemplate "/vocab/{vocabulary}/term/{term}/broaderChain"; api:itemTemplate "{base}/vocab/{vocabulary}/term/{term}"; api:exampleRequestPath "/vocab/nims/term/0038/broaderChain"; api:defaultViewerspec:broaderChainViewer; .
Don’t forget spec:api a api:API; … api:viewer spec:broaderChainViewer, … api:endpoint spec:broaderChainEndpoint, … skos:broader a rdf:Property; api:label "broader"; . skos:prefLabel a rdf:Property; api:label "prefLabel"; .
Using Fuseki assembler cmspv-assembler.ttl: @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> . <#dataset> a ja:RDFDataset ; ja:defaultGraph [ a ja:OntModel ; ja:ontModelSpecja:OWL_MEM_MICRO_RULE_INF ; ja:content [ja:externalContent <http://www.w3.org/2009/08/skos-reference/skos.rdf>, <file:////projects/cmspv/branches/initial_rdf/skos/nims.ttl>] ] . Run fuseki with: fuseki-server --desc=cmspv-assembler.ttl /cmspv
Cherry-pick the rules @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> . @prefix : <#> . <#dataset> a ja:RDFDataset ; ja:graph :inf . :inf a ja:InfModel ; ja:baseModel :data ; ja:reasoner [ ja:reasonerURL <http://jena.hpl.hp.com/2003/GenericRuleReasoner> ; ja:rulesFrom <file:////projects/cmspv/branches/fuseki/skos.rules> ] . :data a ja:MemoryModel ; ja:content [ja:externalContent <http://www.w3.org/2009/08/skos-reference/skos.rdf>, <file:////projects/cmspv/branches/initial_rdf/skos/nims.ttl>] .
The rules file # RDFS Closure rules [rdfs6: (?p rdfs:subPropertyOf ?q), notEqual(?p,?q) -> table(?p, ?q), [ (?a ?q ?b) <- (?a ?p ?b)] ] # inverseOf [inverseOf1: (?P owl:inverseOf ?Q) -> (?Q owl:inverseOf ?P) ] [inverseOf2: (?P owl:inverseOf ?Q) -> table(?P), table(?Q), [inverseOf2b: (?X ?P ?Y) <- (?Y ?Q ?X)] ] # TransitiveProperty [transitiveProperty1: (?P rdf:typeowl:TransitiveProperty) -> table(?P), [transitiveProperty1b: (?A ?P ?C) <- bound (?C), (?B ?P ?C), (?A ?P ?B)] [transitiveProperty1b: (?A ?P ?C) <- unbound (?C), (?A ?P ?B) (?B ?P ?C)] ] # SymmetricProperty [symmetricProperty1: (?P rdf:typeowl:SymmetricProperty) -> table(?P), [symmetricProperty1b: (?X ?P ?Y) <- (?Y ?P ?X)] ]
Direct access • SPARQL endpoint: http://aquarius.tw.rpi.edu:3047/post.html • RDF file: https://scm.escience.rpi.edu/svn/public/projects/cmspv/branches/initial_rdf/skos/nims.ttl