Class: Qa::LinkedData::Mapper::GraphPredicateMapperService

Inherits:
Object
  • Object
show all
Defined in:
app/services/qa/linked_data/mapper/graph_predicate_mapper_service.rb

Class Method Summary collapse

Class Method Details

.map_values(graph:, predicate_map:, subject_uri:) ⇒ <Hash<Symbol><Array<Object>>] mapped result values with hash of map key = array of object values for predicates identified in predicate_map.

Extract predicates specified in the predicate_map from the graph and return as a value map for a single subject URI.

Examples:

predicate_map

{
  uri: :subject_uri,
  id: [#<RDF::URI URI:http://id.loc.gov/vocabulary/identifiers/lccn>],
  label: [#<RDF::URI URI:http://www.w3.org/2004/02/skos/core#prefLabel>],
  altlabel: [#<RDF::URI URI:http://www.w3.org/2004/02/skos/core#altLabel>],
  sort: [#<RDF::URI URI:http://vivoweb.org/ontology/core#rank>]'
}

value map for a single result

{:uri=>[#<RDF::URI:0x3fcff54a829c URI:http://id.loc.gov/authorities/names/n2010043281>],
 :id=>[#<RDF::Literal:0x3fcff4a367b4("n2010043281")>],
 :label=>[#<RDF::Literal:0x3fcff54a9a98("Valli, Sabrina"@en)>],
 :altlabel=>[],
 :sort=>[#<RDF::Literal:0x3fcff54b4c18("2")>]}

Parameters:

  • graph (RDF::Graph) —

    the graph from which to extract result values

  • predicate_map (Hash<Symbol><String||Symbol>) —

    value either maps to a predicate in the graph or is :subject_uri indicating to use the subject uri as the value

  • subject_uri (RDF::URI) —

    the subject within the graph for which the values are being extracted

Returns:

  • (<Hash<Symbol><Array<Object>>] mapped result values with hash of map key = array of object values for predicates identified in predicate_map.) —

    <Hash<Symbol><Array<Object>>] mapped result values with hash of map key = array of object values for predicates identified in predicate_map.



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# File 'app/services/qa/linked_data/mapper/graph_predicate_mapper_service.rb', line 28

def self.map_values(graph:, predicate_map:, subject_uri:)
  value_map = {}
  predicate_map.each do |key, predicate|
    values = predicate == :subject_uri ? [subject_uri] : graph_service.object_values(graph: graph, subject: subject_uri, predicate: predicate)
    value_map[key] = values
  end
  value_map = yield value_map if block_given?
  value_map
end