symfony - 无法将回调断言与没有 data_class 的表单一起使用

Question

我正在创建一个名为 IntervalType 的自定义 FormType。我的 IntervalType 将有两个字段，start并且end是整数类型。此自定义 FormType 将始终在没有data_class.

我想添加一个约束来保证start低于end.

如何在没有 FormType 的情况下直接使用 Symfony\Component\Validator\Constraints\Callback data_class？

这是我的IntervalType，仅供参考：

// src/AppBundle/Form/Type/IntervalType.php
namespace AppBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\Extension\Core\Type\IntegerType;
use Symfony\Component\Validator\Constraints\NotBlank;

class TaskType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('start', IntegerType::class, array(
                'constraints' => array(
                    new NotBlank(),
                ),
            ))
            ->add('end', IntegerType::class, array(
                'constraints' => array(
                    new NotBlank(),
                ),
            ))
        );
    }
}

Answer 1

当表单不使用任何 data_class 时，唯一的选择似乎是回调约束。

namespace AppBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\Extension\Core\Type\IntegerType;
use Symfony\Component\Validator\Constraints\Callback;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Context\ExecutionContextInterface;

class IntervalType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('start', IntegerType::class, array(
                'constraints' => array(
                    new NotBlank(),
                ),
            ))
            ->add('end', IntegerType::class, array(
                'constraints' => array(
                    new NotBlank(),
                    new Callback(array($this, 'validateInterval')),
                ),
            ))
            ->add('submit', SubmitType::class);
    }

    public function validateInterval($value, ExecutionContextInterface $context)
    {
        $form = $context->getRoot();
        $data = $form->getData();

        if ($data['start'] >= $value) {
            $context
                ->buildViolation('The end value has to be higher than the start value')
                ->addViolation();
        }
    }
}