Add i18n cache to speed up form build

lib/simple_form/form_builder.rb

@@ -3,6 +3,7 @@ require 'simple_form/input'
 require 'simple_form/hint'
 require 'simple_form/error'
 require 'simple_form/map_type'
+require 'simple_form/i18n_cache'
 
 module SimpleForm
   class FormBuilder < ActionView::Helpers::FormBuilder
@@ -12,6 +13,7 @@ module SimpleForm
     include SimpleForm::Error
 
     extend SimpleForm::MapType
+    extend SimpleForm::I18nCache
 
     map_type :boolean,  :to => :check_box
     map_type :text,     :to => :text_area

lib/simple_form/i18n_cache.rb

@@ -0,0 +1,18 @@
+module SimpleForm
+  # A lot of configuration valeus are retrived from I18n,
+  # like boolean collection, required string. This module provides
+  # caching facility to speed up form construciton.
+  module I18nCache
+    def i18n_cache(key)
+      get_i18n_cache(key)[I18n.locale] ||= yield.freeze
+    end
+    
+    def get_i18n_cache(key)
+      instance_variable_get(:"@#{key}") || reset_i18n_cache(key)
+    end
+
+    def reset_i18n_cache(key)
+      instance_variable_set(:"@#{key}", {})
+    end
+  end
+end

lib/simple_form/input.rb

@@ -1,6 +1,19 @@
 module SimpleForm
   module Input
 
+    def self.included(base) #:nodoc:
+      base.extend ClassMethods
+    end
+
+    module ClassMethods
+      def boolean_collection
+        i18n_cache :boolean_collection do
+          [ [I18n.t(:"simple_form.true", :default => 'Yes'), true],
+            [I18n.t(:"simple_form.false", :default => 'No'), false] ]
+        end
+      end
+    end
+
     private
 
       def generate_input
@@ -14,7 +27,7 @@ module SimpleForm
         args = [ @attribute ]
 
         if mapping.collection
-          collection = @options[:collection] || boolean_collection
+          collection = @options[:collection] || self.class.boolean_collection
           detect_collection_methods(collection, @options)
           args.push(collection, @options[:value_method], @options[:label_method])
         end
@@ -25,11 +38,6 @@ module SimpleForm
         send(mapping.method, *args)
       end
 
-      def boolean_collection
-        [ [I18n.t(:"simple_form.true", :default => 'Yes'), true],
-          [I18n.t(:"simple_form.false", :default => 'No'), false] ]
-      end
-
       def detect_collection_methods(collection, options)
         sample = collection.first
 

lib/simple_form/label.rb

@@ -1,18 +1,17 @@
 module SimpleForm
   module Label
 
-    def self.included(base)
-      base.class_eval do
-        extend ClassMethods
-        @translate_required_string = {}
-      end
+    def self.included(base) #:nodoc:
+      base.extend ClassMethods
     end
 
-    module ClassMethods
+    module ClassMethods #:nodoc:
       def translate_required_string
-        @translate_required_string[I18n.locale] ||= I18n.t(:"simple_form.required.string", :default =>
-          %[<abbr title="#{translate_required_text}">#{translate_required_mark}</abbr> ]
-        )
+        i18n_cache :translate_required_string do
+          I18n.t(:"simple_form.required.string", :default =>
+            %[<abbr title="#{translate_required_text}">#{translate_required_mark}</abbr> ]
+          )
+        end
       end
 
       def translate_required_text
@@ -42,7 +41,7 @@ module SimpleForm
       end
 
       def required_text
-        attribute_required? ? self.class.translate_required_string : ''
+        attribute_required? ? self.class.translate_required_string.dup : ''
       end
 
       def translate_label

test/input_test.rb

@@ -2,6 +2,10 @@ require 'test_helper'
 
 class InputTest < ActionView::TestCase
 
+  setup do
+    SimpleForm::FormBuilder.reset_i18n_cache :boolean_collection
+  end
+
   test 'input should verify options hash' do
     assert_raise ArgumentError do
       simple_form_for @user do |f|

test/label_test.rb

@@ -3,7 +3,7 @@ require 'test_helper'
 class LabelTest < ActionView::TestCase
 
   setup do
-    SimpleForm::FormBuilder.instance_variable_set(:@translate_required_string, {})
+    SimpleForm::FormBuilder.reset_i18n_cache :translate_required_string
   end
 
   test 'input should generate a label with the text field' do