add ability to specify checked and uncked values for boolean input

CHANGELOG.md

@@ -6,6 +6,9 @@
   ([@nashby](https://github.com/nashby))
 
 ### bug fix
+  * Allow to specify checked and uncked values for boolean input
+  ([@nashby](https://github.com/nashby)).
+  Closes [#643](https://github.com/plataformatec/simple_form/issues/629)
   * Allow to add additional classes only for wrapper.
   ([@nashby](https://github.com/nashby)).
   Closes [#629](https://github.com/plataformatec/simple_form/issues/629)

lib/simple_form/inputs/boolean_input.rb

@@ -34,8 +34,8 @@ def label_input
       # reuse the method for nested boolean style, but with no unchecked value,
       # which won't generate the hidden checkbox. This is the default functionality
       # in Rails > 3.2.1, and is backported in SimpleForm AV helpers.
-      def build_check_box(unchecked_value='0')
-        @builder.check_box(attribute_name, input_html_options, '1', unchecked_value)
+      def build_check_box(unchecked_value = unchecked_value)
+        @builder.check_box(attribute_name, input_html_options, checked_value, unchecked_value)
       end
 
       # Build a checkbox without generating the hidden field. See
@@ -49,7 +49,7 @@ def build_check_box_without_hidden_field
       # we need the hidden field to be *outside* the label (otherwise it
       # generates invalid html - html5 only).
       def build_hidden_field_for_checkbox
-        @builder.hidden_field(attribute_name, :value => '0', :id => nil,
+        @builder.hidden_field(attribute_name, :value => unchecked_value, :id => nil,
                               :disabled => input_html_options[:disabled],
                               :name => input_html_options[:name])
       end
@@ -65,6 +65,14 @@ def inline_label
       def required_by_default?
         false
       end
+
+      def checked_value
+        options.fetch(:checked_value, '1')
+      end
+
+      def unchecked_value
+        options.fetch(:unchecked_value, '0')
+      end
     end
   end
 end

test/inputs/boolean_input_test.rb

@@ -14,6 +14,24 @@ class BooleanInputTest < ActionView::TestCase
     assert_no_select 'label'
   end
 
+  test 'input uses custom checked value' do
+    @user.action = 'on'
+    with_input_for @user, :action, :boolean, :checked_value => 'on', :unchecked_value => 'off'
+    assert_select 'input[type=checkbox][value=on][checked=checked]'
+  end
+
+  test 'input uses custom unchecked value' do
+    @user.action = 'off'
+    with_input_for @user, :action, :boolean, :checked_value => 'on', :unchecked_value => 'off'
+    assert_select 'input[type=checkbox][value=on]'
+    assert_no_select 'input[checked=checked][value=on]'
+  end
+
+  test 'input generates hidden input with custom unchecked value' do
+    with_input_for @user, :action, :boolean, :checked_value => 'on', :unchecked_value => 'off'
+    assert_select 'input[type=hidden][value=off]'
+  end
+
   test 'input uses inline boolean style by default' do
     with_input_for @user, :active, :boolean
     assert_select 'input.boolean + label.boolean.optional'