Class: IqRdf::PredicateNamespace

Inherits:
Object
  • Object
show all
Defined in:
lib/iq_rdf/predicate_namespace.rb

Instance Method Summary collapse

Constructor Details

#initialize(subject, namespace) ⇒ PredicateNamespace

Returns a new instance of PredicateNamespace.



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# File 'lib/iq_rdf/predicate_namespace.rb', line 18

def initialize(subject, namespace)
  @subject = subject
  @predicate_namespace = namespace
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args) ⇒ Object (protected) 



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# File 'lib/iq_rdf/predicate_namespace.rb', line 58

def method_missing(method_name, *args)
  build_predicate(method_name, *args)
end

Instance Method Details

#build_predicate(postfix, *args, &block) ⇒ Object 



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# File 'lib/iq_rdf/predicate_namespace.rb', line 23

def build_predicate(postfix, *args, &block)
  options = args.last.is_a?(::Hash) ? args.pop : {}
  objects = args
  predicate = IqRdf::Predicate.new(@predicate_namespace, postfix, @subject, options[:lang])
  if (block)
    raise ArgumentError, "A predicate may either have arguments or a block, or both." if objects.size > 0
    blank_node = IqRdf::BlankNode.new
    yield blank_node
    predicate << blank_node
  else
    return nil if options[:suppress_if_empty] === true && objects.size == 0
    raise ArgumentError, "At least one object is required in predicate call" if objects.size == 0
    objects.each do |o|
      if o.is_a?(Array)
        return nil if options[:suppress_if_empty] === true && o.size == 0
        o = IqRdf::Collection.new(o)
      elsif o.is_a?(IqRdf::Node)
        raise ArgumentError, "Objects may not have nested triples in this Implementation of RDF" if o.is_subject?
      elsif o.is_a?(Literal)
        # We're already done
      elsif o.is_a?(Symbol)
        o = IqRdf::Default.build_uri(o)
      else
        return nil if options[:suppress_if_empty] === true && (o.nil? || o === "")
        o = Literal.build(o)
      end
      predicate << o
    end
  end
  @subject << predicate
  @subject
end