Add URI constants

Author: abrisse

lib/json/ld.rb

@@ -110,6 +110,11 @@ module LD
 
     MAX_CONTEXTS_LOADED = 50
 
+    # URI Constants
+    RDF_JSON = RDF::URI("#{RDF.to_uri}JSON")
+    RDF_DIRECTION = RDF::URI("#{RDF.to_uri}direction")
+    RDF_LANGUAGE = RDF::URI("#{RDF.to_uri}language")
+
     class JsonLdError < StandardError
       def to_s
         "#{self.class.instance_variable_get :@code}: #{super}"

lib/json/ld/from_rdf.rb

@@ -57,7 +57,7 @@ def from_statements(dataset, useRdfType: false, useNativeTypes: false, extendedR
             extendedRepresentation)
 
           # If predicate is rdf:datatype, note subject in compound literal subjects map
-          if @options[:rdfDirection] == 'compound-literal' && statement.predicate == RDF.to_uri + 'direction'
+          if @options[:rdfDirection] == 'compound-literal' && statement.predicate == RDF_DIRECTION
             compound_literal_subjects[name][subject] ||= true
           end
 
@@ -120,14 +120,14 @@ def from_statements(dataset, useRdfType: false, useNativeTypes: false, extendedR
 
               v.delete('@id')
               v['@value'] = cl_node[RDF.value.to_s].first['@value']
-              if cl_node[RDF.to_uri.to_s + 'language']
-                lang = cl_node[RDF.to_uri.to_s + 'language'].first['@value']
+              if (langs = cl_node[RDF_LANGUAGE.to_s])
+                lang = langs.first['@value']
                 unless /^[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*$/.match?(lang)
                   warn "i18n datatype language must be valid BCP47: #{lang.inspect}"
                 end
                 v['@language'] = lang
               end
-              v['@direction'] = cl_node[RDF.to_uri.to_s + 'direction'].first['@value']
+              v['@direction'] = cl_node[RDF_DIRECTION.to_s].first['@value']
             end
           end
 
@@ -209,7 +209,7 @@ def resource_representation(resource, useNativeTypes, extendedRepresentation)
           rdfDirection = @options[:rdfDirection]
           res = {}
 
-          if resource.datatype == RDF::URI(RDF.to_uri + "JSON") && @context.processingMode('json-ld-1.1')
+          if resource.datatype == RDF_JSON && @context.processingMode('json-ld-1.1')
             res['@type'] = '@json'
             res['@value'] = begin
               ::JSON.parse(resource.object)

lib/json/ld/streaming_writer.rb

@@ -60,7 +60,7 @@ def stream_statement(statement)
 
           pd << if statement.object.resource?
             { '@id' => statement.object.to_s }
-          elsif statement.object.datatype == RDF::URI(RDF.to_uri + "JSON")
+          elsif statement.object.datatype == RDF_JSON
             { "@value" => MultiJson.load(statement.object.to_s), "@type" => "@json" }
           else
             lit = { "@value" => statement.object.to_s }

lib/json/ld/to_rdf.rb

@@ -24,7 +24,7 @@ def item_to_rdf(item, graph_name: nil, quoted: false, &block)
           value = item.fetch('@value')
           datatype = item.fetch('@type', nil)
 
-          datatype = RDF::URI(RDF.to_uri + "JSON") if datatype == '@json'
+          datatype = RDF_JSON if datatype == '@json'
 
           case value
           when RDF::Value
@@ -35,7 +35,7 @@ def item_to_rdf(item, graph_name: nil, quoted: false, &block)
             datatype ||= RDF::XSD.boolean.to_s
           when Numeric
             # Otherwise, if value is a number, then set value to its canonical lexical form as defined in the section Data Round Tripping. If datatype is null, set it to either xsd:integer or xsd:double, depending on if the value contains a fractional and/or an exponential component.
-            value = if datatype == RDF::URI(RDF.to_uri + "JSON")
+            value = if datatype == RDF_JSON
               value.to_json_c14n
             else
               # Don't serialize as double if there are no fractional bits
@@ -62,15 +62,15 @@ def item_to_rdf(item, graph_name: nil, quoted: false, &block)
               when 'compound-literal'
                 cl = RDF::Node.new
                 yield RDF::Statement(cl, RDF.value, item['@value'].to_s)
-                yield RDF::Statement(cl, RDF.to_uri + 'language', item['@language'].downcase) if item['@language']
-                yield RDF::Statement(cl, RDF.to_uri + 'direction', item['@direction'])
+                yield RDF::Statement(cl, RDF_LANGUAGE, item['@language'].downcase) if item['@language']
+                yield RDF::Statement(cl, RDF_DIRECTION, item['@direction'])
                 return cl
               end
             end
 
             # Otherwise, if datatype is null, set it to xsd:string or xsd:langString, depending on if item has a @language key.
             datatype ||= item.key?('@language') ? RDF.langString : RDF::XSD.string
-            value = value.to_json_c14n if datatype == RDF::URI(RDF.to_uri + "JSON")
+            value = value.to_json_c14n if datatype == RDF_JSON
           end
           datatype = RDF::URI(datatype) if datatype && !datatype.is_a?(RDF::URI)