Class: RDF::Graph

Inherits:
Object
  • Object
show all
Defined in:
lib/json/ld/extensions.rb

Instance Method Summary collapse

Instance Method Details

#properties(subject, recalc = false) ⇒ Object

Resource properties

Properties arranged as a hash with the predicate Term as index to an array of resources or literals

Example:

graph.load(':foo a :bar; rdfs:label "An example" .', "http://example.com/")
graph.resources(URI.new("http://example.com/subject")) =>
{
  "http://www.w3.org/1999/02/22-rdf-syntax-ns#type" => \[<http://example.com/#bar>\],
  "http://example.com/#label"                       => \["An example"\]
}



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# File 'lib/json/ld/extensions.rb', line 14

def properties(subject, recalc = false)
  @properties ||= {}
  @properties.delete(subject.to_s) if recalc
  @properties[subject.to_s] ||= begin
    hash = Hash.new
    self.query(:subject => subject) do |statement|
      pred = statement.predicate.to_s

      hash[pred] ||= []
      hash[pred] << statement.object
    end
    hash
  end
end

#type_of(subject) ⇒ Object

Get type(s) of subject, returns a list of symbols



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# File 'lib/json/ld/extensions.rb', line 30

def type_of(subject)
  query(:subject => subject, :predicate => RDF.type).map {|st| st.object}
end