Module: ActiveFedora::SemanticNode

Extended by:
ActiveSupport::Concern
Included in:
Base
Defined in:
lib/active_fedora/semantic_node.rb

Defined Under Namespace

Modules: ClassMethods

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#load_from_solr ⇒ Object

Returns the value of attribute load_from_solr.



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# File 'lib/active_fedora/semantic_node.rb', line 9

def load_from_solr
  @load_from_solr
end

#relationships_loaded ⇒ Object

Returns the value of attribute relationships_loaded.



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# File 'lib/active_fedora/semantic_node.rb', line 9

def relationships_loaded
  @relationships_loaded
end

#subject ⇒ Object

Returns the value of attribute subject.



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# File 'lib/active_fedora/semantic_node.rb', line 9

def subject
  @subject
end

Instance Method Details

#add_relationship(predicate, target, literal = false) ⇒ Object

Add a relationship to the Object.

Parameters:

  • predicate
  • object —

    Either a string URI or an object that is a kind of ActiveFedora::Base



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# File 'lib/active_fedora/semantic_node.rb', line 30

def add_relationship(predicate, target, literal=false)
  object_relations.add(predicate, target, literal)
  rels_ext.content_will_change! if object_relations.dirty
end

#assert_kind_of(n, o, t) ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 11

def assert_kind_of(n, o,t)
  raise "Assertion failure: #{n}: #{o} is not of type #{t}" unless o.kind_of?(t)
end

#build_statement(uri, predicate, target, literal = false) ⇒ Object

Create an RDF statement

Parameters:

  • uri —

    a string represending the subject

  • predicate —

    a predicate symbol

  • target —

    an object to store



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# File 'lib/active_fedora/semantic_node.rb', line 76

def build_statement(uri, predicate, target, literal=false)
  ActiveSupport::Deprecation.warn("ActiveFedora::Base#build_statement has been deprecated.")
  raise "Not allowed anymore" if uri == :self
  target = target.internal_uri if target.respond_to? :internal_uri
  subject =  RDF::URI.new(uri)  #TODO cache
  unless literal or target.is_a? RDF::Resource
    begin
      target_uri = (target.is_a? URI) ? target : URI.parse(target)
      if target_uri.scheme.nil?
        raise ArgumentError, "Invalid target \"#{target}\". Must have namespace."
      end
      if target_uri.to_s =~ /\A[\w\-]+:[\w\-]+\Z/
        raise ArgumentError, "Invalid target \"#{target}\". Target should be a complete URI, and not a pid."
      end
    rescue URI::InvalidURIError
      raise ArgumentError, "Invalid target \"#{target}\". Target must be specified as a literal, or be a valid URI."
    end
  end
  if literal
    object = RDF::Literal.new(target)
  elsif target.is_a? RDF::Resource
    object = target
  else
    object = RDF::URI.new(target)
  end
  RDF::Statement.new(subject, find_graph_predicate(predicate), object)

end

#clear_relationship(predicate) ⇒ Object

Clears all relationships with the specified predicate

Parameters:

  • predicate 


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# File 'lib/active_fedora/semantic_node.rb', line 37

def clear_relationship(predicate)
  relationships(predicate).each do |target|
    object_relations.delete(predicate, target) 
  end
  rels_ext.content_will_change! if object_relations.dirty
end

#conforms_to?(model_class) ⇒ Boolean

Checks that this object is matches the model class passed in. It requires two steps to pass to return true

1. It has a hasModel relationship of the same model
2. kind_of? returns true for the model passed in

This method can most often be used to detect if an object from Fedora that was created with a different model was then used to populate this object.

Parameters:

  • the (Class) —

    model class name to check if an object conforms_to that model

Returns:

  • (Boolean) —

    true if this object conforms to the given model name



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# File 'lib/active_fedora/semantic_node.rb', line 52

def conforms_to?(model_class)
  if self.kind_of?(model_class)
    #check has model and class match
    mod = relationships.first(:predicate=>Predicates.find_graph_predicate(:has_model))
    if mod
      expected = self.class.to_class_uri
      if mod.object.to_s == expected
        return true
      else
        raise "has_model relationship check failed for model #{model_class} raising exception, expected: '#{expected}' actual: '#{mod.object.to_s}'"
      end
    else
      raise "has_model relationship does not exist for model #{model_class} check raising exception"
    end
  else
    raise "kind_of? check failed for model #{model_class}, actual #{self.class} raising exception"
  end
  return false
end

#ids_for_outbound(predicate) ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 161

def ids_for_outbound(predicate)
  (object_relations[predicate] || []).map do |o|
    o = o.to_s if o.kind_of? RDF::Literal
    o.kind_of?(String) ? o.gsub("info:fedora/", "") : o.pid
  end
end

#inbound_relationship_predicates ⇒ Hash

Return hash of inbound relationship names and predicate pairs

Returns:

  • (Hash) —

    A hash of inbound relationship names mapped to predicates used



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# File 'lib/active_fedora/semantic_node.rb', line 203

def inbound_relationship_predicates
  relationship_predicates.has_key?(:inbound) ? relationship_predicates[:inbound] : {}
end

#inbound_relationships(response_format = :uri) ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 117

def inbound_relationships(response_format=:uri)
  rel_values = {}
  inbound_relationship_predicates.each_pair do |name,predicate|
    objects = self.send("#{name}",{:response_format=>response_format})
    items = []
    objects.each do |object|
      if (response_format == :uri)    
        #inbound relationships are always object properties
        items.push(object.internal_uri)
      else
        items.push(object)
      end
    end
    unless items.empty?
      rel_values.merge!({predicate=>items})
    end
  end
  return rel_values  
end

#load_relationships ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 154

def load_relationships
  self.relationships_loaded = true
  content = rels_ext.content
  return unless content.present?
  RelsExtDatastream.from_xml content, rels_ext
end

#object_relations ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 15

def object_relations
  load_relationships if !relationships_loaded
  @object_relations ||= RelationshipGraph.new
end

#outbound_relationship_predicates ⇒ Hash

Return hash of outbound relationship names and predicate pairs

Returns:

  • (Hash) —

    A hash of outbound relationship names mapped to predicates used



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# File 'lib/active_fedora/semantic_node.rb', line 197

def outbound_relationship_predicates
  relationship_predicates.has_key?(:self) ? relationship_predicates[:self] : {}
end

#outbound_relationships ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 137

def outbound_relationships()
  relationships.statements
end

#relationship_predicates ⇒ Hash

Return hash of relationship names and predicate pairs (inbound and outbound). It retrieves this information via the relationships_desc hash in the class.

Returns:

  • (Hash) —

    A hash of relationship names (inbound and outbound) mapped to predicates used



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# File 'lib/active_fedora/semantic_node.rb', line 183

def relationship_predicates
  return @relationship_predicates if @relationship_predicates
  @relationship_predicates = {}
  relationships_desc.each_pair do |subj, names|
    @relationship_predicates[subj] = {}
    names.each_pair do |name, args|
      @relationship_predicates[subj][name] = args[:predicate]
    end
  end
  @relationship_predicates
end

#relationships(*args) ⇒ Object

If no arguments are supplied, return the whole RDF::Graph. if a predicate is supplied as a parameter, then it returns the result of quering the graph with that predicate



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# File 'lib/active_fedora/semantic_node.rb', line 143

def relationships(*args)
  load_relationships if !relationships_loaded

  if args.empty?
    raise "Must have internal_uri" unless internal_uri
    return object_relations.to_graph(internal_uri)
  end
  rels = object_relations[args.first] || []
  rels.map {|o| o.respond_to?(:internal_uri) ? o.internal_uri : o }   #TODO, could just return the object
end

#relationships_are_dirty ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 20

def relationships_are_dirty
  object_relations.dirty
end

#relationships_are_dirty=(val) ⇒ Object 



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# File 'lib/active_fedora/semantic_node.rb', line 23

def relationships_are_dirty=(val)
  object_relations.dirty = val
end

#relationships_desc ⇒ Hash

Return hash that persists relationship metadata defined by has_relationship calls

Examples:

For the following relationship


has_relationship "audio_records", :has_part, :type=>AudioRecord

Results in the following returned by relationships_desc
{:self=>{"audio_records"=>{:type=>AudioRecord, :singular=>nil, :predicate=>:has_part, :inbound=>false}}}

Returns:

  • (Hash) —

    Hash of relationship subject (:self or :inbound) mapped to nested hashs of each relationship name mapped to another hash relationship options



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# File 'lib/active_fedora/semantic_node.rb', line 176

def relationships_desc
  @relationships_desc ||= self.class.relationships_desc
end

#remove_relationship(predicate, obj, literal = false) ⇒ Object

Remove a Rels-Ext relationship from the Object.

Parameters:

  • predicate
  • object —

    Either a string URI or an object that responds to .pid



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# File 'lib/active_fedora/semantic_node.rb', line 111

def remove_relationship(predicate, obj, literal=false)
  object_relations.delete(predicate, obj)
  self.relationships_are_dirty = true
  rels_ext.content_will_change!
end