bug symfony#15945 [Form] trigger deprecation warning when using empty_value (xabbuh)

This PR was merged into the 2.7 branch.

Discussion
----------

[Form] trigger deprecation warning when using empty_value

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#15908
| License       | MIT
| Doc PR        |

The `empty_value` option is deprecated in the `choice`, `date`, and
`time` form types. Therefore, a deprecation warning must be triggered
when the users configures a value for this option.

The `datetime` form type does not need to be updated as it passes
configured values to the `date` and `time` form types which trigger
deprecation warnings anyway.

Commits
-------

405d4a8 trigger deprecation warning when using empty_value

Author: fabpot

src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php

@@ -248,13 +248,8 @@ public function configureOptions(OptionsResolver $resolver)
             return '';
         };
 
-        $emptyValue = function (Options $options) {
-            return $options['required'] ? null : '';
-        };
-
-        // for BC with the "empty_value" option
         $placeholder = function (Options $options) {
-            return $options['empty_value'];
+            return $options['required'] ? null : '';
         };
 
         $choiceListNormalizer = function (Options $options, $choiceList) use ($choiceListFactory) {
@@ -287,6 +282,12 @@ public function configureOptions(OptionsResolver $resolver)
         };
 
         $placeholderNormalizer = function (Options $options, $placeholder) {
+            if (!is_object($options['empty_value']) || !$options['empty_value'] instanceof \Exception) {
+                @trigger_error('The form option "empty_value" is deprecated since version 2.6 and will be removed in 3.0. Use "placeholder" instead.', E_USER_DEPRECATED);
+
+                $placeholder = $options['empty_value'];
+            }
+
             if ($options['multiple']) {
                 // never use an empty value for this case
                 return;
@@ -328,7 +329,7 @@ public function configureOptions(OptionsResolver $resolver)
             'preferred_choices' => array(),
             'group_by' => null,
             'empty_data' => $emptyData,
-            'empty_value' => $emptyValue, // deprecated
+            'empty_value' => new \Exception(), // deprecated
             'placeholder' => $placeholder,
             'error_bubbling' => false,
             'compound' => $compound,
@@ -340,7 +341,6 @@ public function configureOptions(OptionsResolver $resolver)
         ));
 
         $resolver->setNormalizer('choice_list', $choiceListNormalizer);
-        $resolver->setNormalizer('empty_value', $placeholderNormalizer);
         $resolver->setNormalizer('placeholder', $placeholderNormalizer);
         $resolver->setNormalizer('choice_translation_domain', $choiceTranslationDomainNormalizer);
 

src/Symfony/Component/Form/Extension/Core/Type/DateType.php

@@ -175,15 +175,17 @@ public function configureOptions(OptionsResolver $resolver)
             return $options['widget'] !== 'single_text';
         };
 
-        $emptyValue = $placeholderDefault = function (Options $options) {
+        $placeholder = $placeholderDefault = function (Options $options) {
             return $options['required'] ? null : '';
         };
 
-        $placeholder = function (Options $options) {
-            return $options['empty_value'];
-        };
-
         $placeholderNormalizer = function (Options $options, $placeholder) use ($placeholderDefault) {
+            if (!is_object($options['empty_value']) || !$options['empty_value'] instanceof \Exception) {
+                @trigger_error('The form option "empty_value" is deprecated since version 2.6 and will be removed in 3.0. Use "placeholder" instead.', E_USER_DEPRECATED);
+
+                $placeholder = $options['empty_value'];
+            }
+
             if (is_array($placeholder)) {
                 $default = $placeholderDefault($options);
 
@@ -213,7 +215,7 @@ public function configureOptions(OptionsResolver $resolver)
             'format' => $format,
             'model_timezone' => null,
             'view_timezone' => null,
-            'empty_value' => $emptyValue, // deprecated
+            'empty_value' => new \Exception(), // deprecated
             'placeholder' => $placeholder,
             'html5' => true,
             // Don't modify \DateTime classes by reference, we treat
@@ -228,7 +230,6 @@ public function configureOptions(OptionsResolver $resolver)
             'compound' => $compound,
         ));
 
-        $resolver->setNormalizer('empty_value', $placeholderNormalizer);
         $resolver->setNormalizer('placeholder', $placeholderNormalizer);
 
         $resolver->setAllowedValues('input', array(

src/Symfony/Component/Form/Extension/Core/Type/TimeType.php

@@ -163,16 +163,17 @@ public function configureOptions(OptionsResolver $resolver)
             return $options['widget'] !== 'single_text';
         };
 
-        $emptyValue = $placeholderDefault = function (Options $options) {
+        $placeholder = $placeholderDefault = function (Options $options) {
             return $options['required'] ? null : '';
         };
 
-        // for BC with the "empty_value" option
-        $placeholder = function (Options $options) {
-            return $options['empty_value'];
-        };
-
         $placeholderNormalizer = function (Options $options, $placeholder) use ($placeholderDefault) {
+            if (!is_object($options['empty_value']) || !$options['empty_value'] instanceof \Exception) {
+                @trigger_error('The form option "empty_value" is deprecated since version 2.6 and will be removed in 3.0. Use "placeholder" instead.', E_USER_DEPRECATED);
+
+                $placeholder = $options['empty_value'];
+            }
+
             if (is_array($placeholder)) {
                 $default = $placeholderDefault($options);
 
@@ -199,7 +200,7 @@ public function configureOptions(OptionsResolver $resolver)
             'with_seconds' => false,
             'model_timezone' => null,
             'view_timezone' => null,
-            'empty_value' => $emptyValue, // deprecated
+            'empty_value' => new \Exception(), // deprecated
             'placeholder' => $placeholder,
             'html5' => true,
             // Don't modify \DateTime classes by reference, we treat
@@ -214,7 +215,6 @@ public function configureOptions(OptionsResolver $resolver)
             'compound' => $compound,
         ));
 
-        $resolver->setNormalizer('empty_value', $placeholderNormalizer);
         $resolver->setNormalizer('placeholder', $placeholderNormalizer);
 
         $resolver->setAllowedValues('input', array(