Add Globalize2 so that we get some nice fall backs to other languages when a translation is missing in the requested language.

vendor/plugins/globalize2/lib/globalize/model/active_record.rb

@@ -0,0 +1,38 @@
+require 'globalize/translation'
+require 'globalize/locale/fallbacks'
+require 'globalize/model/active_record/adapter'
+require 'globalize/model/active_record/translated'
+
+module Globalize
+  module Model
+    module ActiveRecord
+      class << self                
+        def create_proxy_class(klass)
+          Object.const_set "#{klass.name}Translation", Class.new(::ActiveRecord::Base){
+            belongs_to "#{klass.name.underscore}".intern
+            
+            def locale
+              read_attribute(:locale).to_sym
+            end
+            
+            def locale=(locale)
+              write_attribute(:locale, locale.to_s)
+            end
+          }
+        end
+
+        def define_accessors(klass, attr_names)
+          attr_names.each do |attr_name|
+            klass.send :define_method, attr_name, lambda {
+              globalize.fetch self.class.locale, attr_name
+            }
+            klass.send :define_method, "#{attr_name}=", lambda {|val|
+              globalize.stash self.class.locale, attr_name, val
+              self[attr_name] = val
+            }
+          end
+        end
+      end
+    end
+  end
+end

vendor/plugins/globalize2/lib/globalize/model/active_record/adapter.rb

@@ -0,0 +1,96 @@
+module Globalize
+  module Model
+    class AttributeStash < Hash
+      def contains?(locale, attr_name)
+        locale = locale.to_sym
+        self[locale] ||= {}
+        self[locale].has_key? attr_name        
+      end
+      
+      def read(locale, attr_name)
+        locale = locale.to_sym
+        self[locale] ||= {}
+        self[locale][attr_name]
+      end
+      
+      def write(locale, attr_name, value)
+        locale = locale.to_sym
+        self[locale] ||= {}
+        self[locale][attr_name] = value
+      end
+    end
+    
+    class Adapter
+      def initialize(record)
+        @record = record
+        
+        # TODO what exactly are the roles of cache and stash
+        @cache = AttributeStash.new
+        @stash = AttributeStash.new
+      end
+      
+      def fetch(locale, attr_name)
+        # locale = I18n.locale
+        is_cached = @cache.contains?(locale, attr_name)
+        is_cached ? @cache.read(locale, attr_name) : begin
+          value = fetch_attribute locale, attr_name
+          @cache.write locale, attr_name, value if value && value.locale == locale
+          value
+        end
+      end
+      
+      def stash(locale, attr_name, value)
+        @stash.write locale, attr_name, value
+        @cache.write locale, attr_name, value
+      end
+      
+      def update_translations!
+        @stash.each do |locale, attrs|
+          translation = @record.globalize_translations.find_or_initialize_by_locale(locale.to_s)
+          attrs.each{|attr_name, value| translation[attr_name] = value }
+          translation.save!
+        end
+        @stash.clear
+      end
+      
+      # Clears the cache
+      def clear
+        @cache.clear
+        @stash.clear
+      end
+      
+      private
+      
+      def fetch_attribute(locale, attr_name)
+        fallbacks = I18n.fallbacks[locale].map{|tag| tag.to_s}.map(&:to_sym)
+        
+        # If the translations were included with 
+        # :include => globalize_translations
+        # there is no need to query them again.
+        unless @record.globalize_translations.loaded?
+          translations = @record.globalize_translations.by_locales(fallbacks) 
+        else
+          translations = @record.globalize_translations
+        end
+        result, requested_locale = nil, locale
+
+        # Walk through the fallbacks, starting with the current locale itself, and moving
+        # to the next best choice, until we find a match.
+        # Check the @globalize_set_translations cache first to see if we've just changed the 
+        # attribute and not saved yet.
+        fallbacks.each do |fallback|
+          # TODO should we be checking stash or just cache?
+          result = @stash.read(fallback, attr_name) || begin
+            translation = translations.detect {|tr| tr.locale == fallback }
+            translation && translation.send(attr_name)
+          end
+          if result
+            locale = fallback
+            break
+          end
+        end
+        result && Translation::Attribute.new(result, :locale => locale, :requested_locale => requested_locale)
+      end
+    end
+  end
+end

vendor/plugins/globalize2/lib/globalize/model/active_record/translated.rb

@@ -0,0 +1,154 @@
+module Globalize
+  module Model
+  
+    class MigrationError < StandardError; end
+    class UntranslatedMigrationField < MigrationError; end
+    class MigrationMissingTranslatedField < MigrationError; end
+    class BadMigrationFieldType < MigrationError; end
+  
+    module ActiveRecord
+      module Translated
+        def self.included(base)
+          base.extend ActMethods
+        end
+
+        module ActMethods
+          def translates(*attr_names)
+            options = attr_names.extract_options!
+            options[:translated_attributes] = attr_names
+
+            # Only set up once per class
+            unless included_modules.include? InstanceMethods
+              class_inheritable_accessor :globalize_options, :globalize_proxy
+              
+              include InstanceMethods
+              extend  ClassMethods
+              
+              self.globalize_proxy = Globalize::Model::ActiveRecord.create_proxy_class(self)
+              has_many(
+                :globalize_translations,
+                :class_name   => globalize_proxy.name,
+                :extend       => Extensions,
+                :dependent    => :delete_all,
+                :foreign_key  => class_name.foreign_key
+              )
+
+              after_save :update_globalize_record              
+            end
+
+            self.globalize_options = options
+            Globalize::Model::ActiveRecord.define_accessors(self, attr_names)
+            
+            # Import any callbacks that have been defined by extensions to Globalize2
+            # and run them.
+            extend Callbacks
+            Callbacks.instance_methods.each {|cb| send cb }
+          end
+
+          def locale=(locale)
+            @@locale = locale
+          end
+          
+          def locale
+            (defined?(@@locale) && @@locale) || I18n.locale
+          end          
+        end
+
+        # Dummy Callbacks module. Extensions to Globalize2 can insert methods into here
+        # and they'll be called at the end of the translates class method.
+        module Callbacks
+        end
+        
+        # Extension to the has_many :globalize_translations association
+        module Extensions
+          def by_locales(locales)
+            find :all, :conditions => { :locale => locales.map(&:to_s) }
+          end
+        end
+        
+        module ClassMethods          
+          def method_missing(method, *args)
+            if method.to_s =~ /^find_by_(\w+)$/ && globalize_options[:translated_attributes].include?($1.to_sym)
+              find(:first, :joins => :globalize_translations,
+                   :conditions => [ "#{i18n_attr($1)} = ? AND #{i18n_attr('locale')} IN (?)",
+                                   args.first,I18n.fallbacks[I18n.locale].map{|tag| tag.to_s}])
+            else
+              super
+            end
+          end
+                    
+          def create_translation_table!(fields)
+            translated_fields = self.globalize_options[:translated_attributes]
+            translated_fields.each do |f|
+              raise MigrationMissingTranslatedField, "Missing translated field #{f}" unless fields[f]
+            end
+            fields.each do |name, type|
+              unless translated_fields.member? name 
+                raise UntranslatedMigrationField, "Can't migrate untranslated field: #{name}"
+              end              
+              unless [ :string, :text ].member? type
+                raise BadMigrationFieldType, "Bad field type for #{name}, should be :string or :text"
+              end 
+            end
+            translation_table_name = self.name.underscore + '_translations'
+            self.connection.create_table(translation_table_name) do |t|
+              t.references self.table_name.singularize
+              t.string :locale
+              fields.each do |name, type|
+                t.column name, type
+              end
+              t.timestamps              
+            end
+          end
+
+          def drop_translation_table!
+            translation_table_name = self.name.underscore + '_translations'
+            self.connection.drop_table translation_table_name
+          end
+          
+          private
+          
+          def i18n_attr(attribute_name)
+            self.base_class.name.underscore + "_translations.#{attribute_name}"
+          end          
+        end
+        
+        module InstanceMethods
+          def reload(options = nil)
+            globalize.clear
+            
+            # clear all globalized attributes
+            # TODO what's the best way to handle this?
+            self.class.globalize_options[:translated_attributes].each do |attr|
+              @attributes.delete attr.to_s
+            end
+            
+            super options
+          end
+          
+          def globalize
+            @globalize ||= Adapter.new self
+          end
+          
+          def update_globalize_record
+            globalize.update_translations!
+          end
+          
+          def translated_locales
+            globalize_translations.scoped(:select => 'DISTINCT locale').map {|gt| gt.locale.to_sym }
+          end
+          
+          def set_translations options
+            options.keys.each do |key|
+
+              translation = globalize_translations.find_by_locale(key.to_s) ||
+                globalize_translations.build(:locale => key.to_s)
+              translation.update_attributes!(options[key])
+            end
+          end
+          
+        end
+      end
+    end
+  end
+end