reflect on allow_blank option to determine required status

lib/formtastic.rb

@@ -631,6 +631,8 @@ def method_required?(attribute) #:nodoc:
 
       # Determines whether the given options evaluate to true
       def options_require_validation?(options) #nodoc
+        allow_blank = options[:allow_blank]
+        return !allow_blank unless allow_blank.nil?
         if_condition = !options[:if].nil?
         condition = if_condition ? options[:if] : options[:unless]
 

spec/input_spec.rb

@@ -332,6 +332,19 @@ def should_be_required(options)
                 output_buffer.should have_tag('form li.required')
                 output_buffer.should_not have_tag('form li.optional')
               end
+
+              it 'should not be required if allow_blank is true' do
+                @new_post.class.should_receive(:validators_on).with(:published).any_number_of_times.and_return([
+                  active_model_inclusion_validator([:published], {:in => [false, true], :allow_blank => true})
+                ])
+
+                form = semantic_form_for(@new_post) do |builder|
+                  concat(builder.input(:published))
+                end
+                output_buffer.concat(form) if Formtastic::Util.rails3?
+                output_buffer.should_not have_tag('form li.required')
+                output_buffer.should have_tag('form li.optional')
+              end
             end
 
             # TODO make a matcher for this?