Symfony - Request to Command

YourCommand.php

<?php declare(strict_types=1);

namespace App;

use Webmozart\Assert\Assert;

final class YourCommand
{
    /** @var string */
    private string $foo;

    /** @var array<string> */
    private array $bar;

    public function __construct(string $foo, array $bar)
    {
        // Assert away, make the command as strict (or loose for that matter) as you want
        Assert::minLength($foo, 3);
        Assert::maxLength($foo, 50);
        $this->foo = $foo;

        Assert::allString($bar);
        $this->bar = $bar;
    }
}

YourCommandMapper.php

<?php declare(strict_types=1);

namespace App;

use Symfony\Component\Form\DataMapperInterface;
use Throwable;
use function iterator_to_array;

final class YourCommandMapper implements DataMapperInterface
{
    public function mapDataToForms($data, $forms)
    {
        // Uni-directional is probably fine, otherwise, fill form here with stuff
    }

    public function mapFormsToData($forms, &$data)
    {
        try {
            $forms = iterator_to_array($forms);

            $data = new YourCommand(
                $forms['foo']->getData(),
                $forms['bar']->getData(),
            );
        } catch (Throwable $exception) {
            // Nothing to see here... We just need to catch it so symfony continues and eventually starts validating the form
        }
    }
}

YourCommandType.php

<?php declare(strict_types=1);

namespace App;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Validator\Constraints\Length;
use Symfony\Component\Validator\Constraints\NotBlank;

final class YourCommandType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('foo', TextType::class, [
                'constraints' => [
                    // All the validator constraints you need.
                    new NotBlank(),
                    new Length([
                        'min' => 3,
                        'max' => 50,
                    ]),
                ]
            ])
            // Whatever else you want
            ->add('bar', ChoiceType::class, [
                'choices' => [
                    // ...
                ],
                'multiple' => true,
            ])
        ;

        $builder->setDataMapper(new YourCommandMapper());
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'data_class' => YourCommand::class,
            'empty_data' => null,
            'constraints' => [
                // This is kind of a last resort, in case you missed a constraint on one of the fields
                // Dont rely on this, as the feedback to the user isn't all that usefull
                new NotNull([
                    'message' => 'Something went wrong, please check your request and try again.',
                ]),
            ],
        ]);
    }
}

YourController.php

<?php declare(strict_types=1);

namespace App;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

final class YourController
{
    public function yourAction(Request $request): Response
    {
        $form = $this->createForm(YourCommandType::class);
        $form->submit($request->request->all());

        if ($form->isSubmitted() && $form->isValid()) {
            /** @var YourCommand $command */
            $command = $form->getData();

            // Do things

            return new Response(null, Response::HTTP_NO_CONTENT);
        }

        // Handle form errors
        // $errors = $form->getErrors(true);
        
        return new Response(null, Response::HTTP_BAD_REQUEST);
    }
}