Fedora4 Structure and Sparql Examples

#Install Blazegraph

1. Blazegraph : https://superb-dca2.dl.sourceforge.net/project/bigdata/bigdata/2.1.1/blazegraph.jar
2. java -server -Xmx4g -jar blazegraph.jar

#Document Objectives

1. Explore core and external features
2. Explore Fedora HTML UI
3. Gain insight into content modeling (PCDM)
4. Gain insight into interaction models (LDP)

#Fedora Vagrant Components

1. Solr
2. Triplestore

• (Fuseki, Sesame)
  • Audit Service
  • SPARQL-Query

1. F4
2. LDP / WebAC?? / Memento??
3. Apache Camel

Fedora 4 PCDM Modeling

Final result (structure)

• ● cover/
  • ○ files/
    • ■ cover.jpg
    • ■ cover.tiff
• ● book/
  • ○ members/
    • ■ coverProxy
      • ● favorites/
        • ○ members/
          • ■ bookProxy

Final result (relationships)

• ● cover/
  • ○ pcdm:hasFile
    • ■ cover.jpg
    • ■ cover.tiff
• ● book/
  • ○ pcdm:hasMember
    • ■ cover/
• ● favorites/
  • ○ pcdm:hasMember
    • ■ book/

Final result (relationships)

• pcdm:hasFile <cover.jpg>
• pcdm:hasFile <cover.tiff>
• pcdm:hasMember
• pcdm:hasMember

SPARQL Create Queries

Create a “cover” Container

Make “cover” a pcdm:Object

PREFIX pcdm: <http://pcdm.org/models#>
INSERT {
    <http://localhost:8080/fcrepo/rest/cover>
    rdf:type
    pcdm:Object
}
WHERE { }

Make “cover” a pcdm:Object

PREFIX pcdm: <http://pcdm.org/models#>
INSERT { <> a pcdm:Object }
WHERE { }

Create “files” Container ...contained inside “cover”

Make “files” an ldp:DirectContainer

PREFIX ldp: <http://www.w3.org/ns/ldp#>
PREFIX pcdm: <http://pcdm.org/models#>
INSERT {
    </fcrepo/rest/cover/files/> rdf:type ldp:DirectContainer .
    <> rdf:type pcdm:Object .
    <> ldp:membershipResource </fcrepo/rest/cover/> .
    <> ldp:hasMemberRelation pcdm:hasFile .
}
WHERE { }

Make “files” an ldp:DirectContainer

PREFIX ldp: <http://www.w3.org/ns/ldp#>
PREFIX pcdm: <http://pcdm.org/models#>
INSERT {
   <> a ldp:DirectContainer, pcdm:Object ;
   ldp:membershipResource </fcrepo/rest/cover/> ;
   ldp:hasMemberRelation pcdm:hasFile .
}
WHERE { }

Create some cover binaries... contained inside “files”

• cover.jpg
• cover.tif
• See auto-generated relationship on “cover”
• Fixity

Create a “book” Container

Make “book” a pcdm:Object

PREFIX pcdm: <http://pcdm.org/models#>
INSERT { <> a pcdm:Object }
WHERE { }

Create a “members” Container...contained inside “book”

Make “members” an ldp:IndirectContainer

PREFIX ldp: <http://www.w3.org/ns/ldp#>
PREFIX pcdm: <http://pcdm.org/models#>
PREFIX ore: <http://www.openarchives.org/ore/terms/>
INSERT {
    <> a ldp:IndirectContainer, pcdm:Object ;
    ldp:membershipResource </fcrepo/rest/book/> ;
    ldp:hasMemberRelation pcdm:hasMember ;
    ldp:insertedContentRelation ore:proxyFor .
}
WHERE { }

Create a “coverProxy” Container...contained inside “members”

Make “coverProxy” proxy for...

PREFIX pcdm: <http://pcdm.org/models#>
PREFIX ore: <http://www.openarchives.org/ore/terms/>
INSERT {
   <> a pcdm:Object ;
   ore:proxyFor </fcrepo/rest/cover/> ;
   ore:proxyIn </fcrepo/rest/book/> .
}
WHERE { }

Create a “favorites” Container...Just like “book”, except a pcdm:Collection

Make “favorites” a pcdm:Collection

PREFIX pcdm: <http://pcdm.org/models#>
INSERT { <> a pcdm:Collection }
WHERE { }

Create a “members” Container...contained inside “favorites”

Make “members” an ldp:IndirectContainer

PREFIX ldp: <http://www.w3.org/ns/ldp#>
PREFIX pcdm: <http://pcdm.org/models#>
PREFIX ore: <http://www.openarchives.org/ore/terms/>
INSERT {
   <> a ldp:IndirectContainer, pcdm:Object ;
   ldp:membershipResource </fcrepo/rest/favorites/> ;
   ldp:hasMemberRelation pcdm:hasMember ;
   ldp:insertedContentRelation ore:proxyFor .
}
WHERE { }

Create a “bookProxy” Container...contained inside “members”

Make “bookProxy” proxy for...

PREFIX pcdm: <http://pcdm.org/models#>
PREFIX ore: <http://www.openarchives.org/ore/terms/>
INSERT {
   <> a pcdm:Object ;
   ore:proxyFor </fcrepo/rest/book/> ;
   ore:proxyIn </fcrepo/rest/favorites/> .
}
WHERE { }

Other Features

• Versioning
• Transactions
• Transform
• Authorization

SPARQL SEARCH Queries

Find Collections

prefix pcdm: <http://pcdm.org/models#>
select ?r where {
    ?r a pcdm:Collection
}

Find Resources with Members

prefix pcdm: <http://pcdm.org/models#>
select ?r ?m where {
   ?r pcdm:hasMember ?m
}

Find Resources with TIF files

prefix pcdm: <http://pcdm.org/models#>
prefix fedora: <http://fedora.info/definitions/v4/repository#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
select ?r ?m ?f where {
    ?r pcdm:hasMember ?m .
    ?m pcdm:hasFile ?f .
    ?f fedora:mimeType "image/tiff"^^xsd:string
}

Find Resources with nested TIF files

prefix pcdm: <http://pcdm.org/models#>
prefix fedora: <http://fedora.info/definitions/v4/repository#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
select ?r ?m ?f where {
    ?r pcdm:hasMember+ ?m .
    ?m pcdm:hasFile ?f .
    ?f fedora:mimeType "image/tiff"^^xsd:string
}

Find Binary larger than 1-MB

prefix premis: <http://www.loc.gov/premis/rdf/v1#>
prefix fedora: <http://fedora.info/definitions/v4/repository#>
select ?r ?s where {
   ?r a fedora:Binary .
   ?r premis:hasSize ?s .
FILTER (?s > 100000)
}