conneg.rb in rack-linkeddata-1.1.0

- old
+ new

@@ -16,11 +16,11 @@
   #     use Rack::LinkedData::ContentNegotiation, :format => RDF::NTriples::Format
   #     use Rack::LinkedData::ContentNegotiation, :default => 'application/rdf+xml'
   #
   # @see http://www4.wiwiss.fu-berlin.de/bizer/pub/LinkedDataTutorial/
   class ContentNegotiation
-    DEFAULT_CONTENT_TYPE = "text/plain" # N-Triples
+    DEFAULT_CONTENT_TYPE = "application/n-triples" # N-Triples
     VARY = {'Vary' => 'Accept'}.freeze
 
     # @return [#call]
     attr_reader :app
 
@@ -38,15 +38,19 @@
       @options[:default] = (@options[:default] || DEFAULT_CONTENT_TYPE).to_s
     end
 
     ##
     # Handles a Rack protocol request.
+    # Parses Accept header to find appropriate mime-type and sets content_type accordingly.
     #
+    # Inserts ordered content types into the environment as `ORDERED_CONTENT_TYPES` if an Accept header is present
+    #
     # @param  [Hash{String => String}] env
     # @return [Array(Integer, Hash, #each)]
     # @see    http://rack.rubyforge.org/doc/SPEC.html
     def call(env)
+      env['ORDERED_CONTENT_TYPES'] = parse_accept_header(env['HTTP_ACCEPT']) if env.has_key?('HTTP_ACCEPT')
       response = app.call(env)
       body = response[2].respond_to?(:body) ? response[2].body : response[2]
       case body
         when RDF::Enumerable
           response[2] = body  # Put it back in the response, it might have been a proxy
@@ -134,25 +138,21 @@
     #
     # @param  [String, #to_s] header
     # @return [Array<String>]
     # @see    http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
     def parse_accept_header(header)
-      content_types = header.to_s.split(',').map do |content_type_and_weight|
-        content_type_and_weight.strip!
-        case content_type_and_weight
-          when /^([^;]+);\s*q=(\d+\.\d+)$/
-            [[1.0, $2.to_f].min, $1, content_type_and_weight]
-          when /(\S+)/
-            [1.0, $1, content_type_and_weight]
-          else nil
-        end
-      end
-      content_types.compact! # remove nils
-      content_types = content_types.sort_by { |elem| [elem[0], elem[2].size] }
-      content_types.reverse.map { |elem| elem[1] }
+      entries = header.to_s.split(',')
+      entries.map { |e| accept_entry(e) }.sort_by(&:last).map(&:first)
     end
 
+    def accept_entry(entry)
+      type, *options = entry.delete(' ').split(';')
+      quality = 0 # we sort smallest first
+      options.delete_if { |e| quality = 1 - e[2..-1].to_f if e.start_with? 'q=' }
+      [type, [quality, type.count('*'), 1 - options.size]]
+    end
+
     ##
     # Outputs an HTTP `406 Not Acceptable` response.
     #
     # @param  [String, #to_s] message
     # @return [Array(Integer, Hash, #each)]
@@ -167,10 +167,10 @@
     # @param  [String, #to_s]          message
     # @param  [Hash{String => String}] headers
     # @return [Array(Integer, Hash, #each)]
     def http_error(code, message = nil, headers = {})
       message = http_status(code) + (message.nil? ? "\n" : " (#{message})\n")
-      [code, {'Content-Type' => 'text/plain; charset=utf-8'}.merge(headers), [message]]
+      [code, {'Content-Type' => "#{DEFAULT_CONTENT_TYPE}; charset=utf-8"}.merge(headers), [message]]
     end
 
     ##
     # Returns the standard HTTP status message for the given status `code`.
     #