feature #31294 [Form] Add intl/choice_translation_locale option to TimezoneType (ro0NL)

This PR was merged into the 4.3 branch.

Discussion
----------

[Form] Add intl/choice_translation_locale option to TimezoneType

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #28836
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/issues/11503

final step :)

for now i think any form of grouping is a user concern (i.e. by GMT offset or area name); see #31293 + #31295

having a special built in `group_by' => 'gmt_offset'` util would be nice, and can be done in the future.

includes #31434

Commits
-------

001b930611 [Form] Add intl/choice_translation_locale option to TimezoneType

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

@@ -13,10 +13,12 @@ namespace Symfony\Component\Form\Extension\Core\Type;
 
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+use Symfony\Component\Form\ChoiceList\Loader\IntlCallbackChoiceLoader;
 use Symfony\Component\Form\Exception\LogicException;
 use Symfony\Component\Form\Extension\Core\DataTransformer\DateTimeZoneToStringTransformer;
 use Symfony\Component\Form\Extension\Core\DataTransformer\IntlTimeZoneToStringTransformer;
 use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\Intl\Timezones;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 
@@ -40,19 +42,41 @@ class TimezoneType extends AbstractType
     public function configureOptions(OptionsResolver $resolver)
     {
         $resolver->setDefaults([
+            'intl' => false,
             'choice_loader' => function (Options $options) {
-                $regions = $options->offsetGet('regions', false);
                 $input = $options['input'];
 
+                if ($options['intl']) {
+                    $choiceTranslationLocale = $options['choice_translation_locale'];
+
+                    return new IntlCallbackChoiceLoader(function () use ($input, $choiceTranslationLocale) {
+                        return self::getIntlTimezones($input, $choiceTranslationLocale);
+                    });
+                }
+
+                $regions = $options->offsetGet('regions', false);
+
                 return new CallbackChoiceLoader(function () use ($regions, $input) {
-                    return self::getTimezones($regions, $input);
+                    return self::getPhpTimezones($regions, $input);
                 });
             },
             'choice_translation_domain' => false,
+            'choice_translation_locale' => null,
             'input' => 'string',
             'regions' => \DateTimeZone::ALL,
         ]);
 
+        $resolver->setAllowedTypes('intl', ['bool']);
+
+        $resolver->setAllowedTypes('choice_translation_locale', ['null', 'string']);
+        $resolver->setNormalizer('choice_translation_locale', function (Options $options, $value) {
+            if (null !== $value && !$options['intl']) {
+                throw new LogicException('The "choice_translation_locale" option can only be used if the "intl" option is set to true.');
+            }
+
+            return $value;
+        });
+
         $resolver->setAllowedValues('input', ['string', 'datetimezone', 'intltimezone']);
         $resolver->setNormalizer('input', function (Options $options, $value) {
             if ('intltimezone' === $value && !class_exists(\IntlTimeZone::class)) {
@@ -64,6 +88,13 @@ class TimezoneType extends AbstractType
 
         $resolver->setAllowedTypes('regions', 'int');
         $resolver->setDeprecated('regions', 'The option "%name%" is deprecated since Symfony 4.2.');
+        $resolver->setNormalizer('regions', function (Options $options, $value) {
+            if ($options['intl'] && \DateTimeZone::ALL !== (\DateTimeZone::ALL & $value)) {
+                throw new LogicException('The "regions" option can only be used if the "intl" option is set to false.');
+            }
+
+            return $value;
+        });
     }
 
     /**
@@ -82,10 +113,7 @@ class TimezoneType extends AbstractType
         return 'timezone';
     }
 
-    /**
-     * Returns a normalized array of timezone choices.
-     */
-    private static function getTimezones(int $regions, string $input): array
+    private static function getPhpTimezones(int $regions, string $input): array
     {
         $timezones = [];
 
@@ -99,4 +127,19 @@ class TimezoneType extends AbstractType
 
         return $timezones;
     }
+
+    private static function getIntlTimezones(string $input, string $locale = null): array
+    {
+        $timezones = array_flip(Timezones::getNames($locale));
+
+        if ('intltimezone' === $input) {
+            foreach ($timezones as $name => $timezone) {
+                if ('Etc/Unknown' === \IntlTimeZone::createTimeZone($timezone)->getID()) {
+                    unset($timezones[$name]);
+                }
+            }
+        }
+
+        return $timezones;
+    }
 }

src/Symfony/Component/Form/Tests/Extension/Core/Type/TimezoneTypeTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Form\Tests\Extension\Core\Type;
 
 use Symfony\Component\Form\ChoiceList\View\ChoiceView;
+use Symfony\Component\Intl\Util\IntlTestHelper;
 
 class TimezoneTypeTest extends BaseTypeTest
 {
@@ -83,6 +84,17 @@ class TimezoneTypeTest extends BaseTypeTest
         $this->assertContains(new ChoiceView('Europe/Amsterdam', 'Europe/Amsterdam', 'Europe / Amsterdam'), $choices, '', false, false);
     }
 
+    /**
+     * @group legacy
+     * @expectedDeprecation The option "regions" is deprecated since Symfony 4.2.
+     * @expectedException \Symfony\Component\Form\Exception\LogicException
+     * @expectedExceptionMessage The "regions" option can only be used if the "intl" option is set to false.
+     */
+    public function testFilterByRegionsWithIntl()
+    {
+        $this->factory->create(static::TESTED_TYPE, null, ['regions' => \DateTimeZone::EUROPE, 'intl' => true]);
+    }
+
     /**
      * @requires extension intl
      */
@@ -116,4 +128,54 @@ class TimezoneTypeTest extends BaseTypeTest
         $this->assertNull($form->getData());
         $this->assertNotContains('Europe/Saratov', $form->getConfig()->getAttribute('choice_list')->getValues());
     }
+
+    /**
+     * @requires extension intl
+     */
+    public function testIntlTimeZoneInputWithBcAndIntl()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'intltimezone', 'intl' => true]);
+        $form->submit('Europe/Saratov');
+
+        $this->assertNull($form->getData());
+        $this->assertNotContains('Europe/Saratov', $form->getConfig()->getAttribute('choice_list')->getValues());
+    }
+
+    public function testTimezonesAreSelectableWithIntl()
+    {
+        IntlTestHelper::requireIntl($this, false);
+
+        $choices = $this->factory->create(static::TESTED_TYPE, null, ['intl' => true])
+            ->createView()->vars['choices'];
+
+        $this->assertContains(new ChoiceView('Europe/Amsterdam', 'Europe/Amsterdam', 'Central European Time (Amsterdam)'), $choices, '', false, false);
+        $this->assertContains(new ChoiceView('Etc/UTC', 'Etc/UTC', 'Coordinated Universal Time'), $choices, '', false, false);
+    }
+
+    /**
+     * @requires extension intl
+     */
+    public function testChoiceTranslationLocaleOptionWithIntl()
+    {
+        $choices = $this->factory
+            ->create(static::TESTED_TYPE, null, [
+                'intl' => true,
+                'choice_translation_locale' => 'uk',
+            ])
+            ->createView()->vars['choices'];
+
+        $this->assertContains(new ChoiceView('Europe/Amsterdam', 'Europe/Amsterdam', 'за центральноєвропейським часом (Амстердам)'), $choices, '', false, false);
+        $this->assertContains(new ChoiceView('Etc/UTC', 'Etc/UTC', 'за всесвітнім координованим часом'), $choices, '', false, false);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\LogicException
+     * @expectedExceptionMessage The "choice_translation_locale" option can only be used if the "intl" option is set to true.
+     */
+    public function testChoiceTranslationLocaleOptionWithoutIntl()
+    {
+        $this->factory->create(static::TESTED_TYPE, null, [
+            'choice_translation_locale' => 'uk',
+        ]);
+    }
 }