Add Proc support to CollectionInput

lib/simple_form/inputs/collection_input.rb

@@ -27,7 +27,8 @@ module SimpleForm
       private
 
       def collection
-        @collection ||= (options.delete(:collection) || self.class.boolean_collection).to_a
+        collection = (options.delete(:collection) || self.class.boolean_collection)
+        @collection ||= collection.is_a?(Proc) ? collection.call : collection.to_a
       end
 
       # Select components does not allow the required html tag.

test/inputs/collection_input_test.rb

@@ -161,6 +161,12 @@ class CollectionInputTest < ActionView::TestCase
     assert_select 'label.collection_radio', 'Carlos'
   end
 
+  test 'input should allow using a collection with a Proc' do
+    with_input_for @user, :name, :radio, :collection => Proc.new { ['Jose', 'Carlos' ] }
+    assert_select 'label.collection_radio', 'Jose'
+    assert_select 'label.collection_radio', 'Carlos'
+  end
+
   test 'input should allow overriding only label method for collections' do
     with_input_for @user, :name, :radio,
                           :collection => ['Jose' , 'Carlos'],