Fix broken RDF::Node.uuid. Note that the :grammar option is deprecated and provide some documentation for the :format option. Requires that either uuid or uuidtools gems be loaded.

Fixes #354.

Author: gkellogg

Gemfile

@@ -12,6 +12,10 @@ group :develop do
 
   gem 'rest-client-components'
   gem 'benchmark-ips'
+
+  # Soft dependencies
+  gem 'uuid'
+  gem 'uuidtools'
 end
 
 group :debug do

lib/rdf/model/node.rb

@@ -30,19 +30,28 @@ def self.cache
     ##
     # Returns a blank node with a random UUID-based identifier.
     #
+    # (Depends on availability of either `uuid` or `uuidtools` gems).
+    #
+    # @param  [:default, :compact] format (:default)
+    # Formats supported by the UUID generator:
+    #   * `:default` Produces 36 characters, including hyphens separating the UUID value parts
+    #   * `:compact` Produces a 32 digits (hexadecimal) value with no hyphens
+    #   * `:urn` Adds the prefix urn:uuid: to the default format
     # @param [Regexp] grammar (nil)
     #   a grammar specification that the generated UUID must match
+    #   The UUID is generated such that its initial part is guaranteed
+    #   to match the given `grammar`, e.g. `/^[A-Za-z][A-Za-z0-9]*/`.
+    #   Some RDF storage systems (e.g. AllegroGraph) require this.
+    # Requires that the `uuid` gem be loadable to use `format`
     # @return [RDF::Node]
-    def self.uuid(grammar: nil)
+    def self.uuid(format: :default, grammar: nil)
       case
         when grammar
-          # The UUID is generated such that its initial part is guaranteed
-          # to match the given `grammar`, e.g. `/^[A-Za-z][A-Za-z0-9]*/`.
-          # Some RDF storage systems (e.g. AllegroGraph) require this.
-          # @see http://github.com/bendiken/rdf/pull/43
-          uuid = RDF::Util::UUID.generate(options) until uuid =~ grammar
+          warn "[DEPRECATION] The grammar parameter to RDF::Node#uri is deprecated.\n" +
+               "Called from #{Gem.location_of_caller.join(':')}"
+          uuid = RDF::Util::UUID.generate(format: format) until uuid =~ grammar
         else
-          uuid = RDF::Util::UUID.generate(options)
+          uuid = RDF::Util::UUID.generate(format: format)
       end
       self.new(uuid)
     end

lib/rdf/util/uuid.rb

@@ -14,13 +14,11 @@ module UUID
     # [UUIDTools]: http://rubygems.org/gems/uuidtools
     #
     # @param  [:default, :compact, :urn] format (:default)
-    # @param  [Hash{Symbol => Object}] options
-    #   any options to pass through to the underlying UUID library
     # @return [String] a UUID string
     # @raise  [LoadError] if no UUID library is available
     # @see    http://rubygems.org/gems/uuid
     # @see    http://rubygems.org/gems/uuidtools
-    def self.generate(format: :default, **options)
+    def self.generate(format: :default)
       begin
         require 'uuid'
         ::UUID.generate(format)

spec/model_node_spec.rb

@@ -19,6 +19,27 @@
     end
   end
 
+  describe ".uuid" do
+    it "generates a BNode" do
+      expect(described_class.uuid).to be_a_node
+    end
+
+    it "accepts format: :default" do
+      expect(described_class.uuid(format: :default)).to be_a_node
+    end
+
+    it "accepts format: :compact" do
+      expect(described_class.uuid(format: :compact)).to be_a_node
+    end
+
+    it "accepts grammar: option with deprecation" do
+      expect {
+        expect(described_class.uuid(grammar: /\S+/)).to be_a_node
+      }.to write('[DEPRECATION]').to(:error)
+      expect(described_class.uuid(format: :compact)).to be_a_node
+    end
+  end
+
   context "as method" do
     it "with no args" do
       expect(described_class).to receive(:new).with(no_args)