Ontology

mwarnock edited this page Sep 12, 2010 · 7 revisions

Ontology::Term

The ActiveSesame::Ontology::Term is an object relational mapping for ontology terms. Given an ontology term it will query the triple store to find all relationships of that term.

Relationships

When an ontology term is instantiated it runs a sparql statement to find all relationships and terms related to the given term. It stores the results in a relationship map which can be accessed by the relationship_map method. All methods called on the term try to find the method name in the relationship map and return an ontology term built on the related term. Man that’s confusing without seeing it…

term = ActiveSesame::Ontology::Term.new("http://fakeontology.org/ontology#myTerm") # Runs a sparql query to find all relationships related to this term on the default repository
term.relationships # returns a list of all the relationships found by the sparql query
term.relationship_map # returns a hash of where the key is the relationship and the value is the related ontology term
term.relation1 # returns an ontology term built on the value of the relation1 in the relationship_map

Memoization

The sparql query is run on initialization and memoized until the reset method is called. When chaining methods relationship calls are memoized as well.

term.relationships #Does not rerun the sparql
term.relation1 #Get the term referred to in this relationship
term.relation1.relation2 #Get the term referred to by "relation2" on the term referred to by relation1 on term
term.relation1.relation3 # This does not rerun the sparql for term or relation1
term.reset # Resets all memoization

Creating Triples

place holder