Module: TaliaCore::ActiveSourceParts::Rdf

Included in:
TaliaCore::ActiveSource
Defined in:
lib/talia_core/active_source_parts/rdf.rb

Instance Method Summary collapse

Instance Method Details

#autosave_rdf=(value) ⇒ Object

Set the autosave property. See autosave_rdf?



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# File 'lib/talia_core/active_source_parts/rdf.rb', line 17

def autosave_rdf=(value)
  @autosave_rdf = value
end

#autosave_rdf? ⇒ Boolean

This can be used to turn of automatic rdf creation. Attention: Improperly used this may compromise the integrity of the RDF data. However, it may be used in order to speed up “create” operations that save a record several times and don’t need the RDF data in the meantime.

Returns:

  • (Boolean) 


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# File 'lib/talia_core/active_source_parts/rdf.rb', line 11

def autosave_rdf?
  @autosave_rdf = true unless(defined?(@autosave_rdf))
  @autosave_rdf
end

#create_rdf(force = :false) ⇒ Object

This creates the RDF subgraph for this Source and saves it to disk. This may be an expensive operation since it removes the existing elements. (Could be optimised ;-)

Unless the force option is specified, this will ignore predicates that remain unchanged. This means that writing will be faster if a predicate will not changed, but if database objects were not added through the standard API they’ll be missed

The force option may have three values: :false for normal operation, :force for forcing a complete rewrite and :create - the latter will avoid the cleaning of the elements in the RDF store in case the source is completely new and no triples exist.



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# File 'lib/talia_core/active_source_parts/rdf.rb', line 43

def create_rdf(force = :false)
  self.class.benchmark("\033[32m\033[4m\033[1mActiveSource::RD\033[0m Creating RDF for source", Logger::DEBUG, false) do
    assit(!new_record?, "Record must exist here: #{self.uri}")
    # Get the stuff to write. This will also erase the old data
    
    s_rels = case force 
      when :force 
        prepare_all_predicates_to_write 
      when :create
        prepare_predicates_to_create
      else
        prepare_predicates_to_write
      end
    s_rels.each do |sem_ref|
      # We pass the object on. If it's a SemanticProperty, we need to add
      # the value. If not the RDF handler will detect the #uri method and
      # will add it as Resource.
      obj = sem_ref.object
      value = obj.is_a?(SemanticProperty) ? obj.value : obj
      my_rdf.direct_write_predicate(N::URI.new(sem_ref.predicate_uri), value)
    end
    my_rdf.direct_write_predicate(N::RDF.type, rdf_selftype)
    my_rdf.save
  end
end

#my_rdf ⇒ Object

Returns the RDF object to use for this ActiveSource



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# File 'lib/talia_core/active_source_parts/rdf.rb', line 22

def my_rdf
  @rdf_resource ||= begin
    src = RdfResource.new(uri)
    src.object_class = TaliaCore::ActiveSource
    src
  end
end

#to_rdf ⇒ Object

Creates an RDF/XML resprentation of the source



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# File 'lib/talia_core/active_source_parts/rdf.rb', line 70

def to_rdf
  rdf = String.new

  ActiveSourceParts::Xml::RdfBuilder.open(:target => rdf, :indent => 2) do |builder|
    builder.write_source(self)
  end

  rdf
end