Module: Tripod::EagerLoading

Extended by:
ActiveSupport::Concern
Included in:
Components
Defined in:
lib/tripod/eager_loading.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#object_resources ⇒ Object (readonly)

array of resources that represent the objects of the triples of this resource



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# File 'lib/tripod/eager_loading.rb', line 9

def object_resources
  @object_resources
end

#predicate_resources ⇒ Object (readonly)

array of resources that represent the predicates of the triples of this resource



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# File 'lib/tripod/eager_loading.rb', line 6

def predicate_resources
  @predicate_resources
end

Instance Method Details

#eager_load_object_triples!(opts = {}) ⇒ Object

get all the triples in the db where the object uri is their subject stick the results in this resource’s repo options: labels_only (default false)



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# File 'lib/tripod/eager_loading.rb', line 29

def eager_load_object_triples!(opts={})
  object_uris = []

  if opts[:labels_only]
    construct_query = "CONSTRUCT { ?o <#{RDF::RDFS.label}> ?obj_label } WHERE { <#{self.uri.to_s}> ?p ?o . ?o <#{RDF::RDFS.label}> ?obj_label }"
  else
    construct_query = "CONSTRUCT { ?o ?obj_pred ?obj_label } WHERE { <#{self.uri.to_s}> ?p ?o . ?o ?obj_pred ?obj_label }"
  end

  extra_triples = self.class._graph_of_triples_from_construct_or_describe construct_query
  self.class.add_data_to_repository(extra_triples, self.repository)
end

#eager_load_predicate_triples!(opts = {}) ⇒ Object

get all the triples in the db where the predicate uri is their subject stick the results in this resource’s repo options: labels_only (default false)



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# File 'lib/tripod/eager_loading.rb', line 14

def eager_load_predicate_triples!(opts={})

  if opts[:labels_only]
    construct_query = "CONSTRUCT { ?p <#{RDF::RDFS.label}> ?pred_label } WHERE { <#{self.uri.to_s}> ?p ?o . ?p <#{RDF::RDFS.label}> ?pred_label }"
  else
    construct_query = "CONSTRUCT { ?p ?pred_pred ?pred_label } WHERE { <#{self.uri.to_s}> ?p ?o . ?p ?pred_pred ?pred_label }"
  end

  extra_triples = self.class._graph_of_triples_from_construct_or_describe construct_query
  self.class.add_data_to_repository(extra_triples, self.repository)
end

#get_related_resource(resource_uri, class_of_resource_to_create) ⇒ Object

 get the resource that represents a particular uri. If there’s triples in our repo where that uri  is the subject, use that to hydrate a resource, otherwise justdo a find against the db.



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# File 'lib/tripod/eager_loading.rb', line 44

def get_related_resource(resource_uri, class_of_resource_to_create)
  data_graph = RDF::Graph.new

  self.repository.query( [ RDF::URI.new(resource_uri.to_s), :predicate, :object] ) do |stmt|
    data_graph << stmt
  end

  if data_graph.empty?
    r = nil
  else
    # it's in our eager loaded repo
    r = class_of_resource_to_create.new(resource_uri)
    r.hydrate!(:graph => data_graph)
    r.new_record = false
    r
  end
  r
end