Improve heuristics for generating term statements based on value inspection.

Author: gkellogg

lib/rdf/vocabulary.rb

@@ -625,8 +625,25 @@ def each_statement
               else
                 prop = RDF::Vocabulary.expand_pname(prop.to_s)
                 next unless prop
-                v = RDF::Vocabulary.expand_pname(value.to_s)
-                value = v.valid? ? v : RDF::Literal(value.to_s)
+
+                v = value.to_s
+                value = RDF::Vocabulary.expand_pname(v)
+                unless value && value.valid?
+                  require 'byebug'; byebug if prop.to_s.include?('isDefinedBy')
+                  # Use as most appropriate literal
+                  value = [
+                    RDF::Literal::Date,
+                    RDF::Literal::DateTime,
+                    RDF::Literal::Integer,
+                    RDF::Literal::Decimal,
+                    RDF::Literal::Double,
+                    RDF::Literal::Boolean,
+                    RDF::Literal
+                  ].inject(nil) do |memo, klass|
+                    l = klass.new(v)
+                    memo || (l if l.valid?)
+                  end
+                end
               end
               yield RDF::Statement(self, prop, value)
             rescue KeyError

spec/vocabulary_spec.rb

@@ -349,5 +349,84 @@
       its(:attributes) {is_expected.to include("schema:domainIncludes" => RDF::RDFS.Resource)}
       its(:attributes) {is_expected.to include("schema:rangeIncludes" => [RDF::RDFS.Resource, RDF::RDFS.Class])}
     end
+
+    context "#each_statement" do
+      it "emits statements for a vocabulary" do
+        graph = RDF::Graph.new {|g| RDF::RDFS[""].each_statement {|s| g << s}}
+
+        expect(graph.map(&:subject)).to all(eql(RDF::RDFS.to_uri))
+        expect(graph.query(predicate: RDF.type).map(&:object)).to include RDF::OWL.Ontology
+      end
+
+      {
+        "rdfs:comment" => {term: RDF::RDFS.comment, predicate: RDF::RDFS.comment, value: RDF::Literal(%(A description of the subject resource.))},
+        "rdfs:label" => {term: RDF::RDFS.label, predicate: RDF::RDFS.label, value: RDF::Literal("label")},
+        "rdf:type" => {term: RDF.type, predicate: RDF.type, value: RDF.Property},
+        "rdfs:subClassOf" => {term: RDF::RDFS.Class, predicate: RDF::RDFS.subClassOf, value: RDF::RDFS.Resource},
+        "rdfs:subPropertyOf" => {term: RDF::RDFS.isDefinedBy, predicate: RDF::RDFS.subPropertyOf, value: RDF::RDFS.seeAlso},
+        "rdfs:domain" => {term: RDF::RDFS.domain, predicate: RDF::RDFS.domain, value: RDF.Property},
+        "rdfs:range" => {term: RDF::RDFS.range, predicate: RDF::RDFS.range, value: RDF::RDFS.Class},
+        "schema:domainIncludes" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {domainIncludes: RDF::RDFS.Resource}),
+          predicate: RDF::Vocab::SCHEMA.domainIncludes,
+          value: RDF::RDFS.Resource
+        },
+        "schema:inverseOf" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {inverseOf: RDF::RDFS.Resource}),
+          predicate: RDF::Vocab::SCHEMA.inverseOf,
+          value: RDF::RDFS.Resource
+        },
+        "schema:rangeIncludes" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {rangeIncludes: RDF::RDFS.Resource}),
+          predicate: RDF::Vocab::SCHEMA.rangeIncludes,
+          value: RDF::RDFS.Resource
+        },
+        "vocab value" => {term: RDF::RDFS.isDefinedBy, predicate: RDF::RDFS.isDefinedBy, value: RDF::RDFS.to_uri},
+        "term value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdfs:seeAlso" => "rdfs:seeAlso"}),
+          predicate: RDF::RDFS.seeAlso,
+          value: RDF::RDFS.seeAlso
+        },
+        "uri value" => {term: RDF::RDFS[""], predicate: RDF::RDFS.seeAlso, value: RDF::URI("http://www.w3.org/2000/01/rdf-schema-more")},
+        "date value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "2016-04-24"}),
+          predicate: RDF.value,
+          value: RDF::Literal::Date.new("2016-04-24")
+        },
+        "dateTime value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "2016-04-24T15:22:00"}),
+          predicate: RDF.value,
+          value: RDF::Literal::DateTime.new("2016-04-24T15:22:00")
+        },
+        "boolean value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "true"}),
+          predicate: RDF.value,
+          value: RDF::Literal::Boolean.new(true)
+        },
+        "integer value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "1"}),
+          predicate: RDF.value,
+          value: RDF::Literal::Integer.new(1)
+        },
+        "decimal value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "1.1"}),
+          predicate: RDF.value,
+          value: RDF::Literal::Decimal.new(1.1)
+        },
+        "double value" => {
+          term: RDF::Vocabulary::Term.new(:foo, label: "foo", attributes: {:"rdf:value" => "1.1e1"}),
+          predicate: RDF.value,
+          value: RDF::Literal::Double.new(1.1e1)
+        },
+        "literal value" => {term: RDF::RDFS[""], predicate: RDF::Vocab::DC11.title, value: RDF::Literal("The RDF Schema vocabulary \(RDFS\)")},
+      }.each do |pred, props|
+        it "emits #{pred}" do
+          graph = RDF::Graph.new {|g| props[:term].each_statement {|s| g << s}}
+
+          expect(graph.map(&:subject)).to all(eql(props[:term]))
+          expect(graph.query(predicate: props[:predicate]).map(&:object)).to include props[:value]
+        end
+      end
+    end
   end
 end