Vocabulary Workshop, RAL, February 25, 2009
NERC DataGrid
Vocabulary Server Access
Vocabulary Access
NERC DataGrid
There are five ways to access the
SeaDataNet vocabularies
 Term and list URLs
 HTTP-POX interface
 SOAP API
 BODC client interface
 SeaDataNet Vocabulary Portal
Vocabulary Access
Term and List URLs
NERC DataGrid
 User input is a URL
 Returns an XML document based on
the SKOS standard
 List documents include labels and
definitions for all terms in the list
 Term documents include labels,
definition and mappings for the term
Vocabulary Access
 URL syntax
NERC DataGrid





Namespace base (http://vocab.ndg.nerc.ac.uk/)
‘list’ or ‘term’
List identifier (e.g. P021)
List version or ‘current’
Term identifier for term URL (e.g. TEMP)
 Examples
 List (SeaDataNet Parameter Discovery Vocabulary)
 http://vocab.ndg.nerc.ac.uk/list/P021/current/
 Term (CF Standard Name for sea temperature)
 http://vocab.ndg.nerc.ac.uk/term/P071/current/CFSN0335
Vocabulary Access
<?xml version="1.0" ?>
NERC DataGrid
- <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:skos="http://www.w3.org/2004/02/skos/core#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
- <skos:Concept
rdf:about="http://vocab.ndg.nerc.ac.uk/term/P071/7/CFSN0335">
<skos:externalID>SDN:P071:7:CFSN0335</skos:externalID>
<skos:prefLabel>sea_water_temperature</skos:prefLabel>
<skos:altLabel />
<skos:definition />
<dc:date>2008-02-26T10:02:57.564+0000</dc:date>
<skos:exactMatch
rdf:resource="http://vocab.ndg.nerc.ac.uk/term/P041/4/G963" />
<skos:broadMatch
rdf:resource="http://vocab.ndg.nerc.ac.uk/term/P021/24/TEMP" />
</skos:Concept>
</rdf:RDF>
Vocabulary Access
NERC DataGrid
 In SeaDataNet data and metadata we
use URNs, not URLs (in case the server
namespace changes)
 URN syntax is




Namespace base (SDN)
List identifier (e.g. P021)
List version or null field for ‘current’
Term identifier (e.g. TEMP)
 For example the URL
http://vocab.ndg.nerc.ac.uk/list/P021/current/TEMP is
represented by the URN SDN:P021::TEMP
 URN to URL conversion is simple string slicing
Vocabulary Access
HTTP-POX API
 The API is documented at
http://www.bodc.ac.uk/products/web_services/vocab/methods.html
NERC DataGrid
 User input is a URL
 Returns an XML document based on a BODC-defined
schema
 Provides access to
 List catalogue (names all accessible lists)
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/whatLists
 List contents (keys, terms, abbreviations, definitions,
mappings)
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/getList?recordKey=http://vocab.n
dg.nerc.ac.uk/list/P021/current&earliestRecord=2007-09-01T00:00:00Z
 Plaintext searches across lists
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/searchVocab?listKey=http://vocab
.ndg.nerc.ac.uk/list/P021/current&searchTerm=*emperature*
 Term verification (abbreviation WC_Temp in P021)
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/verifyTerm?listKey=http://vocab.n
dg.nerc.ac.uk/list/P021/current/&entryTerm=WC_Temp&termType=short
Vocabulary Access
 Provides access to
NERC DataGrid
 Mappings
– Complete map between two vocabularies (P031/P021)
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/getMap?subjectList=h
ttp://vocab.ndg.nerc.ac.uk/list/P031/current&predicate=2&objectList=htt
p://vocab.ndg.nerc.ac.uk/list/P021/current&inference=false
– Map of all terms in all vocabularies to one term
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/getRelatedRecordByT
erm?subjectTerm=http://vocab.ndg.nerc.ac.uk/term/P021/current/TEMP
&predicate=255&inferences=true
– Map of all terms in vocabulary (P211) mapped to terms
in a vocabulary (P211) again containing a string (air
temperature).
Too big for PowerPoint. Needs to be copied and pasted
http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/getRelatedRecordByC
riteria?subjectText=air%20temperature&caseSensitivity=false&partialM
atch=true&predicate=255&inferences=false&subjectList=http://vocab.nd
g.nerc.ac.uk/list/P211/current&objectList=http://vocab.ndg.nerc.ac.uk/lis
t/P211/current
Vocabulary Access
 SOAP API
NERC DataGrid
 User input is a programmatic service call from Java, Perl,
PHP, Python, etc. application
 Returns an XML document based on a BODC-defined
schema
 Provides access to
 List catalogue
 List contents (keys, terms, abbreviations, definitions,
mappings)
 Mappings
 Plaintext searches across lists
 Term verification
 The API is documented at
http://www.bodc.ac.uk/products/web_services/vocab/methods.html
 The WSDL is available from http://vocab.ndg.nerc.ac.uk/
Vocabulary Access
 BODC Clients
NERC DataGrid
 A range of clients are available from
http://vocab.ndg.nerc.ac.uk
 vocabServer.jsp
– provides a catalogue of all lists available
» One or more of these may be selected
» ‘Get checked lists’ displays these in a table
rendering
– Allows term labels (full or abbreviated) to be
verified against one or more vocabularies
– Allows free text searches in labels or definitions of
one or more vocabularies
Vocabulary Access
 BODC clients
NERC DataGrid
 There are six ‘method call’ clients that give access to
specific API method calls and a ‘semantic search’
client
 Very basic
 Primarily designed as a production system test
harness
 Some usage tips
– listKeys are specified as list or term URLs
– termType vocabulary is ‘short’, ‘long’, ‘definition’
– If unsure of required predicate set to 255
– Set inference to ‘true’ to include simple inverse
relationships
Vocabulary Access
SeaDataNet Vocabulary Portal
NERC DataGrid
 User input through a web form at
http://seadatanet.maris2.nl/v_bodc_vocab/welcome.aspx
 Returns a human-readable table with
key, term, abbreviation, definition and
modification date columns
 Table may be exported as a
semicolon-delimited ‘CSV’ ASCII file
 Only includes lists considered to be
of interest to SeaDataNet