NERC DataGrid Vocabulary Server Access Vocabulary Workshop, RAL, February 25, 2009

NERC DataGrid Vocabulary Access  There are five ways to access the SeaDataNet vocabularies  Term and list URLs  HTTP-POX interface  SOAP API  BODC client interface  SeaDataNet Vocabulary Portal

NERC DataGrid Vocabulary Access  Term and List URLs  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

NERC DataGrid Vocabulary Access  URL syntax  Namespace base (  ‘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)   Term (CF Standard Name for sea temperature) 

NERC DataGrid Vocabulary Access - SDN:P071:7:CFSN0335 sea_water_temperature T10:02:

NERC DataGrid Vocabulary Access  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 is represented by the URN SDN:P021::TEMP  URN to URL conversion is simple string slicing

NERC DataGrid Vocabulary Access HTTP-POX API  The API is documented at  User input is a URL  Returns an XML document based on a BODC-defined schema  Provides access to  List catalogue (names all accessible lists)  List contents (keys, terms, abbreviations, definitions, mappings) dg.nerc.ac.uk/list/P021/current&earliestRecord= T00:00:00Z  Plaintext searches across lists  Term verification (abbreviation WC_Temp in P021) dg.nerc.ac.uk/list/P021/current/&entryTerm=WC_Temp&termType=short

NERC DataGrid Vocabulary Access  Provides access to  Mappings –Complete map between two vocabularies (P031/P021) 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 erm?subjectTerm= &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 riteria?subjectText=air%20temperature&caseSensitivity=false&partialM atch=true&predicate=255&inferences=false&subjectList= g.nerc.ac.uk/list/P211/current&objectList= t/P211/current

NERC DataGrid Vocabulary Access  SOAP API  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  The WSDL is available from vocab.ndg.nerc.ac.uk/ vocab.ndg.nerc.ac.uk/

NERC DataGrid Vocabulary Access  BODC Clients  A range of clients are available from  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

NERC DataGrid Vocabulary Access  BODC clients  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

NERC DataGrid Vocabulary Access  SeaDataNet Vocabulary Portal  User input through a web form at  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