symfony · peter-gribanov · Jan 23, 2018 · Jan 25, 2018 · Jan 25, 2018 · Jan 25, 2018
diff --git a/UPGRADE-4.1.md b/UPGRADE-4.1.md
@@ -45,6 +45,25 @@ Validator
  * Calling `EmailValidator::__construct()` method with a boolean parameter is deprecated and will be removed in 5.0, use `EmailValidator("strict")` instead.
  * Deprecated the `checkDNS` and `dnsMessage` options of the `Url` constraint. They will be removed in 5.0.
 
+Form
+----
+
+ * Using callable strings as `empty_data` in `ChoiceType` is deprecated and will be removed in Symfony 5.0, use a `\Closure` instead.
+
+  Before:
+
+  ```php
+  'empty_data' => 'some_function',
+  ```
+
+  After:
+
+  ```php
+  'empty_data' => function (FormInterface $form, $data) {
+      return some_function($form, $data);
+  },
+  ```
+
 Workflow
 --------
 

diff --git a/UPGRADE-5.0.md b/UPGRADE-5.0.md
@@ -42,6 +42,25 @@ Validator
  * Calling `EmailValidator::__construct()` method with a boolean parameter has been removed, use `EmailValidator("strict")` instead.
  * Removed the `checkDNS` and `dnsMessage` options from the `Url` constraint.
 
+Form
+----
+
+ * Support for callable strings as `empty_data` in `ChoiceType` has been removed. Use a `\Closure` instead.
+
+  Before:
+
+  ```php
+  'empty_data' => 'some_function',
+  ```
+
+  After:
+
+  ```php
+  'empty_data' => function (FormInterface $form, $data) {
+      return some_function($form, $data);
+  },
+  ```
+
 Workflow
 --------
 

diff --git a/src/Symfony/Component/Form/CHANGELOG.md b/src/Symfony/Component/Form/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.1.0
+-----
+
+ * deprecated support for callable strings as `empty_data` in `ChoiceType`
+
 4.0.0
 -----
 

diff --git a/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php b/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php
@@ -91,7 +91,14 @@ public function buildForm(FormBuilderInterface $builder, array $options)
                     $emptyData = $form->getConfig()->getEmptyData();
 
                     if (false === FormUtil::isEmpty($emptyData) && array() !== $emptyData) {
-                        $data = is_callable($emptyData) ? call_user_func($emptyData, $form, $data) : $emptyData;
+                        if (is_callable($emptyData)) {
+                            if (is_string($emptyData)) {
+                                @trigger_error('Passing callable strings is deprecated since version 4.1 and will be removed in 5.0. You should use a "\Closure" instead.', E_USER_DEPRECATED);
+                            }
+                            $data = call_user_func($emptyData, $form, $data);
+                        } else {
+                            $data = $emptyData;
+                        }
                     }
                 }
 

diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php
@@ -640,6 +640,47 @@ public function testSubmitMultipleChoiceExpandedWithEmptyData()
         $this->assertSame(array('test'), $form->getData());
     }
 
+    /**
+     * @group legacy
+     */
+    public function testSubmitSingleChoiceWithCallableEmptyData()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, array(
+            'multiple' => false,
+            'expanded' => true,
+            'choices' => array('test'),
+            'empty_data' => __CLASS__.'::emptyDataResolver',
+        ));
+
+        $form->submit(null);
+
+        $this->assertSame('test', $form->getData());
+    }
+
+    /**
+     * @return string
+     */
+    public static function emptyDataResolver()
+    {
+        return 'test';
+    }
+
+    public function testSubmitSingleChoiceWithClosureEmptyData()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, array(
+            'multiple' => false,
+            'expanded' => true,
+            'choices' => array('test'),
+            'empty_data' => function () {
+                return 'test';
+            },
+        ));
+
+        $form->submit(null);
+
+        $this->assertSame('test', $form->getData());
+    }
+
     public function testSubmitMultipleNonExpanded()
     {
         $form = $this->factory->create(static::TESTED_TYPE, null, array(