Fix some issues in Choice field with PHP Enums

[javiereguiluz]

Fixes the issues reported in #4988.

[abozhinov]

When you plan to merge it?

[abozhinov]

Hi,
my implementation is:

yield ChoiceField::new('weight.unit', new TranslatableMessage('weight.unit.label'));

#[Embeddable]
final class Weight
{
    #[Column(type: 'float', nullable: false)]
    #[Assert\GreaterThanOrEqual(0)]
    #[Groups(['read', 'write'])]
    private float $value;

    #[Column(type: 'string', nullable: false, enumType: WeightUnit::class)]
    #[Groups(['read', 'write'])]
    private WeightUnit $unit;

The error:

#message: "An error has occurred resolving the options of the form "Symfony\Component\Form\Extension\Core\Type\EnumType": The required option "class" is missing."
  #code: 0
  #file: "[/var/www/html/dreamshop/vendor/symfony/form/ResolvedFormType.php](https://docker.mydreamshop.io/_profiler/open?file=vendor/symfony/form/ResolvedFormType.php&line=78#line78)"

[abozhinov]

On 42 line should set CLASS option -> $field->setFormTypeOption('class', $enumTypeClass);

[abozhinov]

Choices should be ENUM not STRING.

foreach ($choices as $choice) {
    $processedEnumChoices[$choice->name] = $choice;
}

[ksn135]

My work with Enum with the current 4.x branch looks like this:

enum Nds: string
{
    case RATE_NONE = 'rate_none';
    case RATE_ZERO = 'rate_0';
    case RATE_10 = 'rate_10';
    case RATE_20 = 'rate_20';

    public static function choices(): array
    {
        return [
            self::RATE_NONE->getLabel() => self::RATE_NONE->name,
            self::RATE_ZERO->getLabel() => self::RATE_ZERO->name,
            self::RATE_10->getLabel() => self::RATE_10->name,
            self::RATE_20->getLabel() => self::RATE_20->name,
        ];
    }

    public function trans(TranslatorInterface $translator, string $locale = null): string
    {
        return $translator->trans($this->getLabel(), locale: $locale);
    }

    public function getLabel(): string
    {
        return 'admin_label.enum.nds.'.$this->value;
    }

    public function getRate(): int
    {
        return (int) (substr($this->value, 5));
    }
}

# messages.en.yaml
admin_label:
  enum:
    nds:
      rate_none: Without VAT
      rate_0: 0%
      rate_10: 10%
      rate_20: 20%

class MyEnumType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder->addModelTransformer(
            new CallbackTransformer(
                static fn (mixed $value): mixed => $value, // no convertion
                static fn (?string $value): ?\BackedEnum => call_user_func([$options['class'], 'tryFrom'], $value)
            )
        );
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setNormalizer('choice_label', static fn (Options $options, ?\Closure $value): \Closure => static fn ($choice): ?string => self::getTranslatableLabel($options, $choice)); 
        $resolver->setNormalizer('choice_value', static fn (Options $options, ?\Closure $value): \Closure => static fn ($choice): ?string => $choice instanceof \BackedEnum ? $choice->value : $choice);
        $resolver->setRequired('label_prefix');
        $resolver->setAllowedTypes('label_prefix', 'string');
        $resolver->setDefault('label_prefix', 'admin_label.enum.');
        $resolver->setRequired('class');
        $resolver->setAllowedTypes('class', 'string');

    }

    public static function getTranslatableLabel(Options $options, string $value) {
        return $options['label_prefix'] . lcfirst(self::classShortName($options['class'])) . '.' . $value;
    }

    public static function classShortName(string $class): string
    {
        return (false === $pos = strrpos($class, '\\')) ? $class : substr($class, $pos + 1);
    }

    public function getParent(): string
    {
        return EnumType::class;
    }
}

class DocCrudController extends AbstractCrudController
{
...
    public function configureFields(string $pageName): iterable
    {
      ...
        yield Fields\ChoiceField::new('nds', 'admin_label.doc.field.nds')->setRequired(true)
           ->setPermission(DocAccessVoter::SHOW_NDS)
            ->renderAsNativeWidget()
            ->addCssClass('col-md-6 col-xxl-5')
            ->setFormType(MyEnumType::class)
            ->setFormTypeOption('placeholder', false)
            ->setFormTypeOption('class', Nds::class)
            ->setChoices(in_array($pageName, [Crud::PAGE_INDEX, Crud::PAGE_DETAIL], true) ? Nds::choices() : Nds::cases())
        ;
       ...
     }
...
}

[abozhinov]

This is my PR -> #5640

[ksn135]

#5641

[sylvaindeloux]

@javiereguiluz
Is it planned to be merged soon ?
#5641 is quite annoying :/

[javiereguiluz]

Closing in favor of #5740.