Add Duke terms to descMetadata

add_duke_terms_to_desc_metadata.rb

ActiveFedora::Base.find_each({}, {cast: true}) do |obj|
  unless obj.datastreams["descMetadata"].is_a? DulHydra::Datastreams::DescriptiveMetadataDatastream
    puts "SKIPPED #{obj.pid} -- descMetadata is not a DulHydra::Datastreams::DescriptiveMetadataDatastream"
    next
  end
  doc = obj.descMetadata.ng_xml
  if doc.namespaces.include? "xmlns:#{DulHydra::Metadata::DukeTerms::NAMESPACE_PREFIX}"
    puts "SKIPPED #{obj.pid} -- already has Duke terms namespace"
    next
  end
  doc.root.add_namespace(DulHydra::Metadata::DukeTerms::NAMESPACE_PREFIX, 
                         DulHydra::Metadata::DukeTerms::XMLNS)
  obj.descMetadata.content = doc.to_xml
  if obj.save
    obj.reload
    puts "SUCCESS -- #{obj.pid} migrated"
    UpdateEvent.create(pid: obj.pid, summary: "Added XML namespace declaration for Duke terms to descMetadata")
  else
    puts "FAILURE -- #{obj.pid} NOT migrated"
  end
end