Symfony 3.2表单在文本字段上添加过滤器以删除不需要的字符的最佳方式

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;

class MyFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('myField', TextType::class, [
                'label' => 'My Field',
                'required' => true,
                'attr' => [
                    'maxlength' => 100,
                ],
            ]);
    }
}

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;

class MyController extends AbstractController
{
    public function myAction(Request $request)
    {
        $form = $this->createForm(MyFormType::class);

        $form->handleRequest($request);
        if ($form->isSubmitted() && $form->isValid()) {
            // 处理表单提交
            $data = $form->getData();
            // 进行过滤操作
            $filteredValue = $this->filterValue($data['myField']);
            // 其他操作...
        }

        return $this->render('my_template.html.twig', [
            'form' => $form->createView(),
        ]);
    }

    private function filterValue($value)
    {
        // 在这里进行过滤操作，例如使用正则表达式删除不需要的字符
        $filteredValue = preg_replace('/[^a-zA-Z0-9]/', '', $value);

        return $filteredValue;
    }
}