gistfile1.rb

module RDFMapper

  class << self

    def to_rdf(obj)
      mapping = obj.rdf_mapping
      uri = obj.uri

      data = "<#{uri}>\n" unless mapping.empty?

      data = self.parse_mapping(data, mapping, obj)

      if (doc_uri = obj.doc_uri) && (obj.respond_to? :updated_at) && (obj.respond_to? :created_at)
        data += "<#{doc_uri}> a foaf:Document; dc:created \"#{obj.created_at}\"; dc:modified \"#{obj.updated_at}\" .\n\n"
      end

      data
    end

    def parse_mapping(data, mapping, obj)
      unless mapping.empty?
        data += "a #{mapping[:type]};\n"
        mapping.keys.each do |key|
          unless key == :type
            if (value = obj.send(key)) && (value != "") && (value.class != Array)
              value = self.rdf_value(value, obj)
              if mapping[key].class != Array
                data += "#{mapping[key]} #{value};\n" unless key == :type
              else
                mapping[key].each do |k|
                  data += "#{k} #{value};\n" unless key == :type
                end
              end
            elsif value.class == Array
              value.each do |v|
                v = self.rdf_value(v, obj)
                data += "#{mapping[key]} #{v};\n" unless key == :type
              end
            end
          end
        end
        data = data[0, data.length - 2] + ".\n\n" # Getting rid of the previous ;
      end
    end

    def rdf_value(value, obj)
      if value.class == String
        value = "\"#{value}\"^^xsd:string"
      elsif value.class == Fixnum
        value = "\"#{value}\"^^xsd:int"
      elsif value.class == Float
        value = "\"#{value}\"^^xsd:float"
      elsif value.class == URI::HTTP
        value = "<#{value.to_s}>"
      elsif value.class == Hash
        value = "[ #{parse_mapping("", value, obj)} ]"
      elsif value.class == Date
        value = "\"#{value.to_s}\"^^xsd:date"
      elsif value.class == DateTime
        value = "\"#{value.to_s}\"^^xsd:dateTime"
      elsif value.class == Time
        value = "\"#{value.iso8601}\"^^xsd:dateTime"
      elsif value_uri = value.uri
        value = "<#{value_uri}>"
      end
      value
    end

  end

end