Class: ActiveFedora::ChangeSet

Inherits:
Object
  • Object
show all
Defined in:
lib/active_fedora/change_set.rb

Overview

a Hash of properties that have changed and their present values

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(object, graph, changed_attributes) ⇒ ChangeSet

Returns a new instance of ChangeSet.

Parameters:

  • object (ActiveFedora::Base) —

    The resource that has associations and properties

  • graph (RDF::Graph) —

    The RDF graph that holds the current state

  • changed_attributes (Array) —

    A list of properties that have changed



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

def initialize(object, graph, changed_attributes)
  @object = object
  @graph = graph
  @changed_attributes = changed_attributes
end

Instance Attribute Details

#changed_attributes ⇒ Object (readonly)

Returns the value of attribute changed_attributes.



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# File 'lib/active_fedora/change_set.rb', line 4

def changed_attributes
  @changed_attributes
end

#graph ⇒ Object (readonly)

Returns the value of attribute graph.



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# File 'lib/active_fedora/change_set.rb', line 4

def graph
  @graph
end

#object ⇒ Object (readonly)

Returns the value of attribute object.



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# File 'lib/active_fedora/change_set.rb', line 4

def object
  @object
end

Instance Method Details

#changes ⇒ Hash<RDF::URI, RDF::Queryable::Enumerator>

Returns hash of predicate uris to statements.

Returns:

  • (Hash<RDF::URI, RDF::Queryable::Enumerator>) —

    hash of predicate uris to statements



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# File 'lib/active_fedora/change_set.rb', line 18

def changes
  @changes ||= changed_attributes.each_with_object({}) do |key, result|
    if object.association(key.to_sym).present?
      # This is always an ActiveFedora::Reflection::RDFPropertyReflection
      predicate = object.association(key.to_sym).reflection.predicate
      result[predicate] = graph.query({ subject: object.rdf_subject, predicate: predicate })
    elsif object.class.properties.keys.include?(key)
      predicate = graph.reflections.reflect_on_property(key).predicate
      results = graph.query({ subject: object.rdf_subject, predicate: predicate })
      new_graph = child_graphs(results.map(&:object))
      results.each do |res|
        new_graph << res
      end
      result[predicate] = new_graph
    elsif key == 'type'.freeze
      # working around https://github.com/ActiveTriples/ActiveTriples/issues/122
      predicate = ::RDF.type
      result[predicate] = graph.query({ subject: object.rdf_subject, predicate: predicate })
    elsif object.local_attributes.include?(key)
      raise "Unable to find a graph predicate corresponding to the attribute: \"#{key}\""
    end
  end
end