Add support to file method.

lib/simple_form.rb

@@ -35,4 +35,8 @@ module SimpleForm
   # How the label text should be generated altogether with the required text.
   mattr_accessor :label_text
   @@label_text = lambda { |label, required| "#{required} #{label}" }
+
+  # Collection of methods to detect if a file type was given.
+  mattr_accessor :file_methods
+  @@file_methods = [ :file?, :public_filename ]
 end

lib/simple_form/components/input.rb

@@ -17,6 +17,7 @@ module SimpleForm
       map_type :select,   :to => :collection_select, :options => true, :collection => true
       map_type :radio,    :to => :collection_radio, :collection => true
       map_type :string,   :to => :text_field
+      map_type :file,     :to => :file_field
 
       # Numeric types
       map_type :integer, :float, :decimal, :to => :text_field

lib/simple_form/form_builder.rb

@@ -265,12 +265,24 @@ module SimpleForm
         when :timestamp
           :datetime
         when :string, nil
-          @attribute.to_s =~ /password/ ? :password : :string
+          match = case @attribute.to_s
+            when /password/  then :password
+            when /time_zone/ then :time_zone
+            when /country/   then :country
+          end
+
+          match || input_type || file_method? || :string
         else
           input_type
       end
     end
 
+    # Checks if attribute is a file_method.
+    def file_method? #:nodoc:
+      file = @object.send(@attribute) if @object.respond_to?(@attribute)
+      :file if file && SimpleForm.file_methods.any? { |m| file.respond_to?(m) }
+    end
+
     # Finds the database column for the given attribute
     def find_attribute_column #:nodoc:
       @object.column_for_attribute(@attribute) if @object.respond_to?(:column_for_attribute)

test/components/input_test.rb

@@ -78,6 +78,11 @@ class InputTest < ActionView::TestCase
     assert_select 'input#user_name[type=hidden]'
   end
 
+  test 'input should generate a file field' do
+    with_input_for @user, :name, :file
+    assert_select 'input#user_name[type=file]'
+  end
+
   test 'input should generate a datetime select by default for datetime attributes' do
     with_input_for @user, :created_at, :datetime
     1.upto(5) do |i|

test/form_builder_test.rb

@@ -88,6 +88,15 @@ class FormBuilderTest < ActionView::TestCase
     assert_select 'form select#user_updated_at_1i.datetime'
   end
 
+  test 'builder should generate file for file columns' do
+    @user.avatar = mock("file")
+    @user.avatar.expects(:respond_to?).with(:file?).returns(false)
+    @user.avatar.expects(:respond_to?).with(:public_filename).returns(true)
+
+    with_form_for @user, :avatar
+    assert_select 'form input#user_avatar.file'
+  end
+
   test 'build should generate select if a collection is given' do
     with_form_for @user, :age, :collection => 1..60
     assert_select 'form select#user_age.select'