Order vocabulary page with ICU to handle each language collation

_plugins/alphab_for.rb

@@ -0,0 +1,75 @@
+require 'yaml'
+require 'ffi-icu'
+
+#alphab_for allows to loop in an array sorted by the translated value of
+#each key using appropriate collation for the current language. Example :
+#{% alphab_for v in page.voc %}
+#  ..
+#{% endalphab_for %}
+
+module Jekyll
+  module AlphabForImpl
+    def render(context)
+      #load translations files
+      site = context.registers[:site].config
+      if !site.has_key?("loc")
+        site['loc'] = {}
+        site['langs'].each do |key,value|
+          site['loc'][key] = YAML.load_file('_translations/'+key+'.yml')[key]
+        end
+      end
+      #load collection and context variables
+      sorted_collection = collection_to_sort context
+      return if sorted_collection.empty?
+      lang = Liquid::Template.parse('{{page.lang}}').render context
+      page = Liquid::Template.parse('{{page.id}}').render context
+      #build translated array and associative hash
+      translated = []
+      assoc = {}
+      for key in sorted_collection do
+        next if !site['loc'][lang].has_key?(page) || !site['loc'][lang][page].has_key?(key) || site['loc'][lang][page][key].nil?
+        t = site['loc'][lang][page][key]
+        translated.push(t)
+        assoc[key] = t
+      end
+      #sort translated array using appropriate collation
+      translated = ICU::Collation.collate(lang, translated)
+      #recreate collection with new ordering
+      sorted_collection = []
+      for va in translated do
+        val = assoc.select{|k,v| v == va}
+        #compatibility with old ruby versions that return an Array
+        if val.is_a?(Array)
+          val = { val[0][0] => va }
+        end
+        val = val.keys[0]
+        sorted_collection.push(val)
+      end
+      #return modified array
+      original_name = @collection_name
+      result = nil
+      context.stack do
+        sorted_collection_name = "#{@collection_name}_sorted".sub('.', '_')
+        context[sorted_collection_name] = sorted_collection
+        @collection_name = sorted_collection_name
+        result = super
+        @collection_name = original_name
+      end
+      result
+    end
+  end
+ 
+  class AlphabForTag < Liquid::For
+    include AlphabForImpl
+ 
+    def collection_to_sort(context)
+      return context[@collection_name].dup
+    end
+ 
+    def end_tag
+      'endalphab_for'
+    end
+  end
+end
+ 
+Liquid::Template.register_tag('alphab_for', Jekyll::AlphabForTag)