Added error notification class and id as configuration option

lib/generators/simple_form/templates/simple_form.rb

@@ -22,6 +22,12 @@ SimpleForm.setup do |config|
   # Default tag used for error notification helper.
   # config.error_notification_tag = :p
 
+  # CSS class to add for error notification helper.
+  # config.error_notification_class = ''
+
+  # ID to add for error notification helper.
+  # config.error_notification_id = ''
+
   # You can wrap all inputs in a pre-defined tag.
   # config.wrapper_tag = :div
 

lib/simple_form.rb

@@ -35,6 +35,14 @@ module SimpleForm
   mattr_accessor :error_notification_tag
   @@error_notification_tag = :p
 
+  # CSS class to add for error notification helper.
+  mattr_accessor :error_notification_class
+  @@error_notification_class = nil
+
+  # ID to add for error notification helper.
+  mattr_accessor :error_notification_id
+  @@error_notification_id = nil
+
   # Components used by the form builder.
   mattr_accessor :components
   @@components = [ :label_input, :hint, :error ]

lib/simple_form/error_notification.rb

@@ -26,7 +26,9 @@ module SimpleForm
     end
 
     def html_options
-      @options[:class] = "error_notification #{@options[:class]}".strip
+      css_class = SimpleForm.error_notification_class || @options[:class]
+      @options[:class] = "error_notification #{css_class}".strip
+      @options[:id] = SimpleForm.error_notification_id if SimpleForm.error_notification_id
       @options
     end