feature #31195 [Form] Add intltimezone input to TimezoneType (ro0NL)

This PR was squashed before being merged into the 4.3-dev branch (closes #31195).

Discussion
----------

[Form] Add intltimezone input 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 | #22302 (ref #28836)
| License       | MIT
| Doc PR        | symfony/symfony-docs#11463

cc @rvanlaak

Commits
-------

e169dfb [Form] Add intltimezone input to TimezoneType

src/Symfony/Component/Form/Extension/Core/DataTransformer/IntlTimeZoneToStringTransformer.php

@@ -0,0 +1,84 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataTransformer;
+
+use Symfony\Component\Form\DataTransformerInterface;
+use Symfony\Component\Form\Exception\TransformationFailedException;
+
+/**
+ * Transforms between a timezone identifier string and a IntlTimeZone object.
+ *
+ * @author Roland Franssen <franssen.roland@gmail.com>
+ */
+class IntlTimeZoneToStringTransformer implements DataTransformerInterface
+{
+    private $multiple;
+
+    public function __construct(bool $multiple = false)
+    {
+        $this->multiple = $multiple;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function transform($intlTimeZone)
+    {
+        if (null === $intlTimeZone) {
+            return;
+        }
+
+        if ($this->multiple) {
+            if (!\is_array($intlTimeZone)) {
+                throw new TransformationFailedException('Expected an array of \IntlTimeZone objects.');
+            }
+
+            return array_map([new self(), 'transform'], $intlTimeZone);
+        }
+
+        if (!$intlTimeZone instanceof \IntlTimeZone) {
+            throw new TransformationFailedException('Expected a \IntlTimeZone object.');
+        }
+
+        return $intlTimeZone->getID();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function reverseTransform($value)
+    {
+        if (null === $value) {
+            return;
+        }
+
+        if ($this->multiple) {
+            if (!\is_array($value)) {
+                throw new TransformationFailedException('Expected an array of timezone identifier strings.');
+            }
+
+            return array_map([new self(), 'reverseTransform'], $value);
+        }
+
+        if (!\is_string($value)) {
+            throw new TransformationFailedException('Expected a timezone identifier string.');
+        }
+
+        $intlTimeZone = \IntlTimeZone::createTimeZone($value);
+
+        if ('Etc/Unknown' === $intlTimeZone->getID()) {
+            throw new TransformationFailedException(sprintf('Unknown timezone identifier "%s".', $value));
+        }
+
+        return $intlTimeZone;
+    }
+}

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

@@ -13,7 +13,9 @@
 
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+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\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
@@ -27,6 +29,8 @@ public function buildForm(FormBuilderInterface $builder, array $options)
     {
         if ('datetimezone' === $options['input']) {
             $builder->addModelTransformer(new DateTimeZoneToStringTransformer($options['multiple']));
+        } elseif ('intltimezone' === $options['input']) {
+            $builder->addModelTransformer(new IntlTimeZoneToStringTransformer($options['multiple']));
         }
     }
 
@@ -38,17 +42,25 @@ public function configureOptions(OptionsResolver $resolver)
         $resolver->setDefaults([
             'choice_loader' => function (Options $options) {
                 $regions = $options->offsetGet('regions', false);
+                $input = $options['input'];
 
-                return new CallbackChoiceLoader(function () use ($regions) {
-                    return self::getTimezones($regions);
+                return new CallbackChoiceLoader(function () use ($regions, $input) {
+                    return self::getTimezones($regions, $input);
                 });
             },
             'choice_translation_domain' => false,
             'input' => 'string',
             'regions' => \DateTimeZone::ALL,
         ]);
 
-        $resolver->setAllowedValues('input', ['string', 'datetimezone']);
+        $resolver->setAllowedValues('input', ['string', 'datetimezone', 'intltimezone']);
+        $resolver->setNormalizer('input', function (Options $options, $value) {
+            if ('intltimezone' === $value && !class_exists(\IntlTimeZone::class)) {
+                throw new LogicException('Cannot use "intltimezone" input because the PHP intl extension is not available.');
+            }
+
+            return $value;
+        });
 
         $resolver->setAllowedTypes('regions', 'int');
         $resolver->setDeprecated('regions', 'The option "%name%" is deprecated since Symfony 4.2.');
@@ -73,11 +85,15 @@ public function getBlockPrefix()
     /**
      * Returns a normalized array of timezone choices.
      */
-    private static function getTimezones(int $regions): array
+    private static function getTimezones(int $regions, string $input): array
     {
         $timezones = [];
 
         foreach (\DateTimeZone::listIdentifiers($regions) as $timezone) {
+            if ('intltimezone' === $input && 'Etc/Unknown' === \IntlTimeZone::createTimeZone($timezone)->getID()) {
+                continue;
+            }
+
             $parts = explode('/', $timezone);
 
             if (\count($parts) > 2) {

src/Symfony/Component/Form/Tests/Extension/Core/DataTransformer/IntlTimeZoneToStringTransformerTest.php

@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests\Extension\Core\DataTransformer;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Form\Extension\Core\DataTransformer\IntlTimeZoneToStringTransformer;
+
+/**
+ * @requires extension intl
+ */
+class IntlTimeZoneToStringTransformerTest extends TestCase
+{
+    public function testSingle()
+    {
+        $transformer = new IntlTimeZoneToStringTransformer();
+
+        $this->assertNull($transformer->transform(null));
+        $this->assertNull($transformer->reverseTransform(null));
+
+        $this->assertSame('Europe/Amsterdam', $transformer->transform(\IntlTimeZone::createTimeZone('Europe/Amsterdam')));
+        $this->assertEquals(\IntlTimeZone::createTimeZone('Europe/Amsterdam'), $transformer->reverseTransform('Europe/Amsterdam'));
+    }
+
+    public function testMultiple()
+    {
+        $transformer = new IntlTimeZoneToStringTransformer(true);
+
+        $this->assertNull($transformer->transform(null));
+        $this->assertNull($transformer->reverseTransform(null));
+
+        $this->assertSame(['Europe/Amsterdam'], $transformer->transform([\IntlTimeZone::createTimeZone('Europe/Amsterdam')]));
+        $this->assertEquals([\IntlTimeZone::createTimeZone('Europe/Amsterdam')], $transformer->reverseTransform(['Europe/Amsterdam']));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function testInvalidTimezone()
+    {
+        (new IntlTimeZoneToStringTransformer())->transform(1);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function testUnknownTimezone()
+    {
+        (new IntlTimeZoneToStringTransformer(true))->reverseTransform(['Foo/Bar']);
+    }
+}

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

@@ -65,6 +65,15 @@ public function testDateTimeZoneInput()
         $this->assertEquals([new \DateTimeZone('Europe/Amsterdam'), new \DateTimeZone('Europe/Paris')], $form->getData());
     }
 
+    public function testDateTimeZoneInputWithBc()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'datetimezone']);
+        $form->submit('Europe/Saratov');
+
+        $this->assertEquals(new \DateTimeZone('Europe/Saratov'), $form->getData());
+        $this->assertContains('Europe/Saratov', $form->getConfig()->getAttribute('choice_list')->getValues());
+    }
+
     /**
      * @group legacy
      * @expectedDeprecation The option "regions" is deprecated since Symfony 4.2.
@@ -76,4 +85,38 @@ public function testFilterByRegions()
 
         $this->assertContains(new ChoiceView('Europe/Amsterdam', 'Europe/Amsterdam', 'Amsterdam'), $choices, '', false, false);
     }
+
+    /**
+     * @requires extension intl
+     */
+    public function testIntlTimeZoneInput()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, \IntlTimeZone::createTimeZone('America/New_York'), ['input' => 'intltimezone']);
+
+        $this->assertSame('America/New_York', $form->createView()->vars['value']);
+
+        $form->submit('Europe/Amsterdam');
+
+        $this->assertEquals(\IntlTimeZone::createTimeZone('Europe/Amsterdam'), $form->getData());
+
+        $form = $this->factory->create(static::TESTED_TYPE, [\IntlTimeZone::createTimeZone('America/New_York')], ['input' => 'intltimezone', 'multiple' => true]);
+
+        $this->assertSame(['America/New_York'], $form->createView()->vars['value']);
+
+        $form->submit(['Europe/Amsterdam', 'Europe/Paris']);
+
+        $this->assertEquals([\IntlTimeZone::createTimeZone('Europe/Amsterdam'), \IntlTimeZone::createTimeZone('Europe/Paris')], $form->getData());
+    }
+
+    /**
+     * @requires extension intl
+     */
+    public function testIntlTimeZoneInputWithBc()
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, ['input' => 'intltimezone']);
+        $form->submit('Europe/Saratov');
+
+        $this->assertNull($form->getData());
+        $this->assertNotContains('Europe/Saratov', $form->getConfig()->getAttribute('choice_list')->getValues());
+    }
 }