Module: ActiveFedora::RdfNode

Extended by:
ActiveSupport::Autoload, ActiveSupport::Concern
Includes:
ActiveFedora::Rdf::NestedAttributes
Included in:
RDFDatastream, RdfList
Defined in:
lib/active_fedora/rdf_node.rb,
lib/active_fedora/rdf_node/term_proxy.rb

Defined Under Namespace

Modules: ClassMethods Classes: Builder, TermProxy

Class Method Summary collapse

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 188

def method_missing(name, *args)
  if md = /^([^=]+)=$/.match(name.to_s)
      set_value(rdf_subject, md[1], *args)  
  elsif find_predicate(name)
      get_values(rdf_subject, name)
  else 
    super
  end
rescue ActiveFedora::UnregisteredPredicateError
  super
end

Class Method Details

.rdf_registry ⇒ Object

Mapping from URI to ruby class



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# File 'lib/active_fedora/rdf_node.rb', line 10

def self.rdf_registry
  @@rdf_registry ||= {}
end

Instance Method Details

#==(other_object) ⇒ Object

Comparison Operator Checks that 

* RDF subject id (URI) is same
* Class is the same
* Both objects reference the same RDF graph in memory



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# File 'lib/active_fedora/rdf_node.rb', line 19

def ==(other_object)
  self.class == other_object.class &&
  self.rdf_subject.id == other_object.rdf_subject.id &&
  self.graph.object_id == other_object.graph.object_id
end

#append(subject, predicate, args) ⇒ Object

append a value

Parameters:

  • predicate (Symbol, RDF::URI) —

    the predicate to insert into the graph



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# File 'lib/active_fedora/rdf_node.rb', line 158

def append(subject, predicate, args)
  options = config_for_term_or_uri(predicate)
  graph.insert([subject, predicate, args])
end

#attributes=(values) ⇒ Object

Parameters:

  • [Hash] (Hash) —

    a customizable set of options

Raises:

  • (ArgumentError) 


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# File 'lib/active_fedora/rdf_node.rb', line 126

def attributes=(values)
  raise ArgumentError, "values must be a Hash, you provided #{values.class}" unless values.kind_of? Hash
  values.with_indifferent_access.each do |key, value|
    if self.class.config.keys.include?(key)
      set_value(rdf_subject, key, value)
    elsif nested_attributes_options.keys.map{ |k| "#{k}_attributes"}.include?(key)
      send("#{key}=".to_sym, value)
    end
  end
end

#config_for_term_or_uri(term) ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 163

def config_for_term_or_uri(term)
  case term
  when RDF::URI
    self.class.config.each { |k, v| return v if v[:predicate] == term}
  else
    self.class.config[term.to_sym]
  end
end

#delete_predicate(subject, predicate, values = nil) ⇒ Object 



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

def delete_predicate(subject, predicate, values = nil)
  predicate = find_predicate(predicate) unless predicate.kind_of? RDF::URI

  if values.nil?
    query = RDF::Query.new do
      pattern [subject, predicate, :value]
    end

    query.execute(graph).each do |solution|
      graph.delete [subject, predicate, solution.value]
    end
  else
    Array(values).each do |v|
      graph.delete [subject, predicate, v]
    end
  end
  reset_child_cache!
end

#destroy ⇒ Object

Be careful with destroy. It will still be in the cache untill you call reset()



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# File 'lib/active_fedora/rdf_node.rb', line 104

def destroy
  # delete any statements about this rdf_subject
  subject = rdf_subject
  query = RDF::Query.new do
    pattern [subject, :predicate, :value]
  end

  query.execute(graph).each do |solution|
    graph.delete [subject, solution.predicate, solution.value]
  end

  # delete any statements that reference this rdf_subject
  query = RDF::Query.new do
    pattern [:subject, :predicate, subject]
  end

  query.execute(graph).each do |solution|
    graph.delete [solution.subject, solution.predicate, subject]
  end
end

#find_predicate(term) ⇒ Object

Parameters:

  • term (Symbol, RDF::URI) —

    predicate the predicate to insert into the graph



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# File 'lib/active_fedora/rdf_node.rb', line 173

def find_predicate(term)
  conf = config_for_term_or_uri(term)
  conf ? conf[:predicate] : nil
end

#get_values(subject, term) ⇒ Object

Parameters:

  • subject (RDF::URI) —

    the base node to start the search from

  • term (Symbol) —

    the term to get the values for



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# File 'lib/active_fedora/rdf_node.rb', line 45

def get_values(subject, term)
  options = config_for_term_or_uri(term)
  predicate = options[:predicate]
  @target ||= {}
  @target[term.to_s] ||= TermProxy.new(self, subject, predicate, options)
end

#mark_for_destruction ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 59

def mark_for_destruction
  @marked_for_destruction = true
end

#marked_for_destruction? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_fedora/rdf_node.rb', line 63

def marked_for_destruction?
  @marked_for_destruction
end

#new_record=(val) ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 67

def new_record= val
  @new_record = val
end

#new_record? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_fedora/rdf_node.rb', line 71

def new_record?
  @new_record
end

#query(subject, predicate, &block) ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 178

def query subject, predicate, &block
  predicate = find_predicate(predicate) unless predicate.kind_of? RDF::URI
  
  q = RDF::Query.new do
    pattern [subject, predicate, :value]
  end

  q.execute(graph, &block)
end

#rdf_subject ⇒ Object

Get the subject for this rdf object



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# File 'lib/active_fedora/rdf_node.rb', line 27

def rdf_subject
  @subject ||= begin
    s = self.class.rdf_subject.call(self)
    s &&= RDF::URI.new(s) if s.is_a? String
    s
  end
end

#reset_child_cache! ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 39

def reset_child_cache!
  @target = {}
end

#reset_rdf_subject! ⇒ Object 



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# File 'lib/active_fedora/rdf_node.rb', line 35

def reset_rdf_subject!
  @subject = nil
end

#set_value(subject, term, values) ⇒ Object

if there are any existing statements with this predicate, replace them

Parameters:

  • subject (RDF::URI) —

    the subject to insert into the graph

  • predicate (Symbol, RDF::URI) —

    the predicate to insert into the graph

  • values (Array, #to_s) —

    the value/values to insert into the graph



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# File 'lib/active_fedora/rdf_node.rb', line 79

def set_value(subject, term, values)
  options = config_for_term_or_uri(term)
  predicate = options[:predicate]
  values = Array(values)

  remove_existing_values(subject, predicate, values)

  values.each do |arg|
    if arg.respond_to?(:rdf_subject) # an RdfObject
      graph.insert([subject, predicate, arg.rdf_subject ])
    else
      arg = arg.to_s if arg.kind_of? RDF::Literal
      graph.insert([subject, predicate, arg])
    end
  end

  @target ||= {}
  proxy = @target[term.to_s]
  proxy ||= TermProxy.new(self, subject, predicate, options)
  proxy.reset!
  proxy

end

#target_class(predicate) ⇒ Object 



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

def target_class(predicate)
  _, conf = self.class.config_for_predicate(predicate)
  class_name = conf[:class_name]
  return nil unless class_name
  ActiveFedora.class_from_string(class_name, self.class)
end