Add Accept-Language negotiation.

lib/webbed/helpers/request_headers_helper.rb

@@ -58,7 +58,7 @@ def referer=(referer)
         headers['Referer'] = referer.to_s
       end
 
-      # The accepted Media Ranges of the Request (as defined in the Allow Header).
+      # The accepted Media Ranges of the Request (as defined in the Accept Header).
       #  
       # @return [<Webbed::MediaRange>, nil]
       def accepted_media_ranges
@@ -71,7 +71,7 @@ def accepted_media_ranges
         end
       end
 
-      # Sets the accepted Media Ranges of the Request (as defined in the Allow Header).
+      # Sets the accepted Media Ranges of the Request (as defined in the Accept Header).
       # 
       # @param [<#to_s>] accepted_media_ranges
       def accepted_media_ranges=(accepted_media_ranges)
@@ -87,7 +87,7 @@ def accepted_media_ranges=(accepted_media_ranges)
       def preferred_media_ranges
         accepted_media_ranges = self.accepted_media_ranges
 
-        # Fix the broken `text/html` Media Range.
+        # Fix the broken `text/xml` Media Range.
         text_xml = accepted_media_ranges.find { |media_type| media_type.mime_type == 'text/xml' }
         application_xml = accepted_media_ranges.find { |media_type| media_type.mime_type == 'application/xml' }
         if text_xml && application_xml
@@ -126,6 +126,59 @@ def negotiate_media_type(media_types)
         matches.sort! { |a, b| b[1] <=> a[1] }
         matches[0] ? matches[0][0] : nil
       end
+
+      # The accepted language ranges of the Request (as defined in the Accept-Language Header).
+      #  
+      # @return [<Webbed::LanguageRange>, nil]
+      def accepted_language_ranges
+        if headers['Accept-Language']
+          headers['Accept-Language'].split(/\s*,\s*/).each_with_index.map do |language_tag, index|
+            Webbed::LanguageRange.new(language_tag, :order => index)
+          end
+        else
+          [Webbed::LanguageRange.new('*')]
+        end
+      end
+
+      # Sets the accepted language ranges of the Request (as defined in the Accept-Language Header).
+      # 
+      # @param [<#to_s>] accepted_language_ranges
+      def accepted_language_ranges=(accepted_language_ranges)
+        headers['Accept-Language'] = accepted_language_ranges.join(', ')
+      end
+
+      # Sorts the accepted language ranges of the Request in order of preference.
+      # 
+      # @return [<Webbed::LanguageRange>]
+      def preferred_language_ranges
+        accepted_language_ranges.sort.reverse
+      end
+
+      # Negotiates which language tag to use based on the accepted language ranges.
+      # 
+      # @param [<Webbed::LanguageTag>] language_tags
+      # @return [Webbed::LanguageTag, nil]
+      def negotiate_language_tag(language_tags)
+        preferred_language_ranges = self.preferred_language_ranges
+        matches = []
+
+        language_tags.each do |language_tag|
+          language_tag_match = nil
+
+          preferred_language_ranges.each do |language_range|
+            if language_range.include?(language_tag) && (!language_tag_match || language_tag_match.specificity < language_range.specificity)
+              language_tag_match = language_range
+            end
+          end
+
+          if language_tag_match && language_tag_match.quality != 0
+            matches.push([language_tag, language_tag_match])
+          end
+        end
+
+        matches.sort! { |a, b| b[1] <=> a[1] }
+        matches[0] ? matches[0][0] : nil
+      end
     end
   end
 end

lib/webbed/language_range.rb

@@ -6,16 +6,26 @@ class LanguageRange < LanguageTag
     # @return [Fixnum]
     attr_reader :quality
 
+    # The order of the language range.
+    # 
+    # @return [Fixnum]
+    attr_accessor :order
+
     Q_REGEX = /(?:\s*;\s*q\s*=\s*(.*))?/
     STAR_REGEX = /(\*)#{Q_REGEX}/
     TAG_REGEX = /[a-zA-Z]{0,8}/
     LANGUAGE_TAG_REGEX = /(#{TAG_REGEX}(?:-#{TAG_REGEX})*)#{Q_REGEX}/
 
-    # (see Webbed::LanguageTag#initialize)
-    def initialize(string)
+    # Creates a new language range.
+    # 
+    # @param [String] tag
+    # @param [Hash] options the options to create the language range with
+    # @option options [Fixnum] :order (0) the order of the language range
+    def initialize(string, options = {})
       STAR_REGEX =~ string || LANGUAGE_TAG_REGEX =~ string
       super($1)
       @quality = $2
+      @order = options.fetch(:order, 0)
     end
 
     # Whether or not the language range is a catch-all.

lib/webbed/media_range.rb

@@ -6,6 +6,9 @@ class MediaRange < MediaType
     GLOBAL_GROUP_REGEX = /^(\*)\/(\*)$/
     TYPE_GROUP_REGEX = /^([-\w.+]+)\/(\*)$/
 
+    # The order of the Media Range.
+    # 
+    # @return [Fixnum]
     attr_accessor :order
 
     # Creates a new Media Range.
@@ -15,7 +18,7 @@ class MediaRange < MediaType
     # @option options [Fixnum] :order (0) the order of the Media Range
     # @see Webbed::MediaType#initialize
     def initialize(media_range, options = {})
-      self.order = options.delete(:order) || 0
+      self.order = options.fetch(:order, 0)
       super(media_range)
     end
 

test/webbed/helpers/request_headers_helper_test.rb

@@ -140,42 +140,81 @@ def setup
       end
 
       test '#accepted_language_ranges' do
-        assert_equal '*/*', @request.accepted_media_ranges[0].mime_type
-        assert_equal 1, @request.accepted_media_ranges[0].quality
-        assert_equal 0, @request.accepted_media_ranges[0].order
+        assert_equal '*', @request.accepted_language_ranges[0].range
+        assert_equal 1, @request.accepted_language_ranges[0].quality
+        assert_equal 0, @request.accepted_language_ranges[0].order
+
+        @request.headers['Accept-Language'] = 'en-gb; q=0.5, en-us, x-pig-latin; q=0.8, i-cherokee, *'
+        assert_equal 'en-gb', @request.accepted_language_ranges[0].range
+        assert_equal 0.5, @request.accepted_language_ranges[0].quality
+        assert_equal 0, @request.accepted_language_ranges[0].order
+        assert_equal 'en-us', @request.accepted_language_ranges[1].range
+        assert_equal 1.0, @request.accepted_language_ranges[1].quality
+        assert_equal 1, @request.accepted_language_ranges[1].order
+        assert_equal 'x-pig-latin', @request.accepted_language_ranges[2].range
+        assert_equal 0.8, @request.accepted_language_ranges[2].quality
+        assert_equal 2, @request.accepted_language_ranges[2].order
+        assert_equal 'i-cherokee', @request.accepted_language_ranges[3].range
+        assert_equal 1.0, @request.accepted_language_ranges[3].quality
+        assert_equal 3, @request.accepted_language_ranges[3].order
+        assert_equal '*', @request.accepted_language_ranges[4].range
+        assert_equal 1.0, @request.accepted_language_ranges[4].quality
+        assert_equal 4, @request.accepted_language_ranges[4].order
+
+        @request.accepted_language_ranges = ['en', Webbed::LanguageRange.new('en-gb'), 'en-gb-foo', '*']
+        assert_equal 'en, en-gb, en-gb-foo, *', @request.headers['Accept-Language']
+        assert_equal 'en', @request.accepted_language_ranges[0].range
+        assert_equal 1.0, @request.accepted_language_ranges[0].quality
+        assert_equal 0, @request.accepted_language_ranges[0].order
+        assert_equal 'en-gb', @request.accepted_language_ranges[1].range
+        assert_equal 1.0, @request.accepted_language_ranges[1].quality
+        assert_equal 1, @request.accepted_language_ranges[1].order
+        assert_equal 'en-gb-foo', @request.accepted_language_ranges[2].range
+        assert_equal 1.0, @request.accepted_language_ranges[2].quality
+        assert_equal 2, @request.accepted_language_ranges[2].order
+        assert_equal '*', @request.accepted_language_ranges[3].range
+        assert_equal 1.0, @request.accepted_language_ranges[3].quality
+        assert_equal 3, @request.accepted_language_ranges[3].order
+      end
+
+      test '#preferred_language_ranges' do
+        assert_equal '*', @request.preferred_language_ranges[0].to_s
+
+        @request.headers['Accept-Language'] = 'en;q=0.3, en-gb;q=0.7, en-gb-foo, en-gb-bar, en-gb-bar;q=0.4, *;q=0.5'
+        assert_equal 'en-gb-foo', @request.preferred_language_ranges[0].to_s
+        assert_equal 'en-gb-bar', @request.preferred_language_ranges[1].to_s
+        assert_equal 'en-gb; q=0.7', @request.preferred_language_ranges[2].to_s
+        assert_equal '*; q=0.5', @request.preferred_language_ranges[3].to_s
+        assert_equal 'en-gb-bar; q=0.4', @request.preferred_language_ranges[4].to_s
+        assert_equal 'en; q=0.3', @request.preferred_language_ranges[5].to_s
+      end
+
+      test '#negotiate_language_tag' do
+        en_gb = Webbed::LanguageTag.new('en-gb')
+        i_cherokee = Webbed::LanguageTag.new('i-cherokee')
 
-        @request.headers['Accept'] = 'text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c, */*'
-        assert_equal 'text/plain', @request.accepted_media_ranges[0].mime_type
-        assert_equal 0.5, @request.accepted_media_ranges[0].quality
-        assert_equal 0, @request.accepted_media_ranges[0].order
-        assert_equal 'text/html', @request.accepted_media_ranges[1].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[1].quality
-        assert_equal 1, @request.accepted_media_ranges[1].order
-        assert_equal 'text/x-dvi', @request.accepted_media_ranges[2].mime_type
-        assert_equal 0.8, @request.accepted_media_ranges[2].quality
-        assert_equal 2, @request.accepted_media_ranges[2].order
-        assert_equal 'text/x-c', @request.accepted_media_ranges[3].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[3].quality
-        assert_equal 3, @request.accepted_media_ranges[3].order
-        assert_equal '*/*', @request.accepted_media_ranges[4].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[4].quality
-        assert_equal 4, @request.accepted_media_ranges[4].order
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb])
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb, i_cherokee])
 
-        @request.accepted_media_ranges = ['text/*', Webbed::MediaType.new('text/html'), 'text/html;level=1', '*/*']
-        assert_equal 'text/*, text/html, text/html;level=1, */*', @request.headers['Accept']
-        assert_equal 'text/*', @request.accepted_media_ranges[0].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[0].quality
-        assert_equal 0, @request.accepted_media_ranges[0].order
-        assert_equal 'text/html', @request.accepted_media_ranges[1].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[1].quality
-        assert_equal 1, @request.accepted_media_ranges[1].order
-        assert_equal 'text/html', @request.accepted_media_ranges[2].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[2].quality
-        assert_equal '1', @request.accepted_media_ranges[2].parameters['level']
-        assert_equal 2, @request.accepted_media_ranges[2].order
-        assert_equal '*/*', @request.accepted_media_ranges[3].mime_type
-        assert_equal 1.0, @request.accepted_media_ranges[3].quality
-        assert_equal 3, @request.accepted_media_ranges[3].order
+        @request.headers['Accept-Language'] = 'i'
+        assert_nil @request.negotiate_language_tag([en_gb])
+        assert_equal i_cherokee, @request.negotiate_language_tag([en_gb, i_cherokee])
+
+        @request.headers['Accept-Language'] = 'i, en'
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb])
+        assert_equal i_cherokee, @request.negotiate_language_tag([en_gb, i_cherokee])
+
+        @request.headers['Accept-Language'] = 'en, i'
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb])
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb, i_cherokee])
+
+        @request.headers['Accept-Language'] = 'en;q=0, i'
+        assert_nil @request.negotiate_language_tag([en_gb])
+        assert_equal i_cherokee, @request.negotiate_language_tag([en_gb, i_cherokee])
+
+        @request.headers['Accept-Language'] = 'en, en-gb;q=0.2, i;q=0.5'
+        assert_equal en_gb, @request.negotiate_language_tag([en_gb])
+        assert_equal i_cherokee, @request.negotiate_language_tag([en_gb, i_cherokee])
       end
     end
   end

test/webbed/language_range_test.rb

@@ -101,5 +101,23 @@ class LanguageRangeTest < TestCase
       other_with_q = Webbed::LanguageRange.new('en-gb; q=0.99')
       assert_equal 0.99, other_with_q.quality
     end
+
+    test '#<=>' do
+      language_range_high_quality = Webbed::LanguageRange.new('en-gb')
+      language_range_low_quality = Webbed::LanguageRange.new('x-pig-latin;q=0.2')
+      language_range_ordered_0 = Webbed::LanguageRange.new('en-gb;q=0.5', :order => 0)
+      language_range_ordered_1 = Webbed::LanguageRange.new('en-gb;q=0.5', :order => 1)
+      language_range_ordered_2 = Webbed::LanguageRange.new('en-gb;q=0.5', :order => 2)
+
+      language_ranges = [
+        language_range_low_quality,
+        language_range_ordered_2,
+        language_range_ordered_1,
+        language_range_ordered_0,
+        language_range_high_quality
+      ]
+
+      assert_equal(language_ranges, language_ranges.shuffle.sort)
+    end
   end
 end

test/webbed/media_range_test.rb

@@ -64,21 +64,15 @@ class MediaRangeTest < TestCase
       media_range_ordered_1 = Webbed::MediaRange.new('text/html;q=0.5', :order => 1)
       media_range_ordered_2 = Webbed::MediaRange.new('text/html;q=0.5', :order => 2)
 
-      shuffled_media_ranges = [
-        media_range_high_quality,
-        media_range_low_quality,
-        media_range_ordered_0,
-        media_range_ordered_1,
-        media_range_ordered_2
-      ].shuffle
-
-      assert_equal([
+      media_ranges = [
         media_range_low_quality,
         media_range_ordered_2,
         media_range_ordered_1,
         media_range_ordered_0,
         media_range_high_quality
-      ], shuffled_media_ranges.sort)
+      ]
+
+      assert_equal(media_ranges, media_ranges.shuffle.sort)
     end
 
     test '#specificity' do