Symfony4/5 forms Cheatsheet

FormType / Configuration

// /src/Form/Type/FooFormType.php

namespace App\Form\Type;

class fooFormType extends AbstractType
{
    // Inject a service
    protected $myService;
    public function __construct(MyService $myService)
    {
        $this->myService = $myService;
    }

    // Configure options
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'action' => '/my/url/',
            'csrf_protection' => false,
            'method' => 'GET',

            // bind to a data class (form binding returns this object as result)
            'data_class' => Foo::class,

            // pass custom options to the form
            'myOption => '',
        ]);
    }

    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        // Set a dynamic action
        $builder->setAction('/foo/ . $options['myOption'];

        $builder->add('first_name', TextType::class, [
            'required' => false,
            'label' => 'First name',
            'attr' => ['placeholder' => 'Enter your first name'],
        ]);

        $builder->add('secret', HiddenType::class, [
            'empty_data' => 'default',
            'required' => false,
            'label' => 'Secret',
        ]);
        // Set value for hidden
        $builder->setData(['bereich' => $options['bereich']]);


        // Use service
        $this->myService->doSomething();

        // Use options
        $options['myOption'];
    }
}

Set Placeholder for TextType Field

Why not support 'placeholder' option like in ChoiceType?
https://github.com/symfony/symfony/issues/45214

$builder->add('location', TextType::class, [
    'attr' => ['placeholder' => 'Town or State)'],
]);

Form Builder

With a lot of options

    $formBuilder = $formFactory->createNamedBuilder(
        'filterForm',
        FormType::class,
        null,
        ['csrf_protection' => false,
        'attr' => ['id' => 'filter-form']
    ]);

    $formBuilder->setMethod('GET');

Controller / Action / Usage

namespace App\Controller;

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

class myController extends AbstractController {

    public function myAction(Request $request,
                             FormFactoryInterface $formFactory
    ) {
        // With data class 'Foo' and options
        $form = $this->createForm(FooFormType::class, $foo, [
            'myOption' => 'some value',
        ]);

        $form->handleRequest($request);

        // Or if you don't want to clear missing fields
        $form->submit($request->get($form->getName()), false);

        // Check for valid form
        if (!($form->isSubmitted() && $form->isValid())) {

            // Debugging only. Giving true to ->getErrors() is very important!!!
            dd($form->isSubmitted(), $form->isValid(), $form->getErrors(true));
            throw new \RuntimeException('Form is not submitted or not valid');
        }

        return $this->renderForm('myTemplate.html.twig', [
            'form' => $form,
        ]);

    }

}

Do not clear missing fields

We have a form object and set some defaults, then we create the form with it.

Does not work because it clears missing fields:

```
$form->handleRequest($request);
```

Use instead:

$form->submit($request->get($form->getName()), false);

Use custom prefix or without prefix / form name

With custom form name / prefix

If set to empty string '' -> <input name="first_name"> instead of <input name="foo[first_name]">

use Symfony\Component\Form\FormFactoryInterface;

public function myAction(Request $request, FormFactoryInterface $formFactory ) {

    $form = $this->formFactory->createNamed('', FooType::class);
}

Wishlist

Allow to change values in bound form (e.g. update "offset" pagination field)

Allow to set form name (field prefix) in config:

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'name' => 'my_prefix',

Renders: <input name="my_prefix[first_name]">

Support 'placeholder' option in all suitable form field types (like in ChoiceType)
Form Twig functions are cumbersome for custom attributes like CSS classes -> no IDE autocompletion e.g. for Bootstrap
Allow to get the form as http url / query similar to JS
- ```
new URLSearchParams(newFormData(formElement))
```
- or PHP http_build_query()
  - ```
  $form->getHttpParams()
```

Handle CKEditor Upload Data

src/Form/Type/CKEditorFormType.php

<?php

namespace App\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\FileType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Validator\Constraints\File;

class CKEditorFormType extends AbstractType
{

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'csrf_protection' => false,
        ]);
    }

    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder->add('upload', FileType::class, [
           'required' => false,
            'constraints' => [
                new File([
                    'maxSize' => '2048k',
                    'mimeTypes' => [
                        'image/jpeg',
                        'image/x-png',
                    ],
                    'mimeTypesMessage' => 'Please upload a valid image',
                ])
            ],
        ]);

    }

}

Controller:

    public function CkEditorUpload(Request $request, FormFactoryInterface $formFactory)
    {
        //create form with empty name/prefix to handle plain POST variables
        $form = $this->formFactory->createNamed('', CKEditorFormType::class);

        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            $file = $form->get('upload')->getData();

            ... validate and process file
        }

Use validator constraints for file upload

Controller:

// Inject ValidatorInterface $validator

/* @var UploadedFile $file */
 $file = $request->files->get('upload');

 if ($file) {
            $violations = $validator->validate($file, new Image([
                'maxSize' => '8192k',
                'mimeTypes' => [
                    'image/jpeg',
                    'image/x-png',
                ],
            ]));
            if (count($violations)) {
                $response = new Response($violations[0]->getMessage(), 400);

                return $response;
            }

            $originalFilename = pathinfo($file->getClientOriginalName(), PATHINFO_FILENAME);
            $safeFilename = $slugger->slug($originalFilename);
            $newFilename = $safeFilename . '-' . uniqid() . '.' . $file->guessExtension();

            try {
                $uploadDir = $kernel->getProjectDir() . '/public/uploads';
                $file->move( $uploadDir, $newFilename);
            } catch (FileException $e) {
                $response = new Response('Error: uploaded file could not be saved.', 400);

                return $response;
            }

Custom Validator Constraints

Constraints also work well for conditional validation.

e.g. cross check if a username exists in the other of two tables:

src/Validator/Constraints/UniqueUsername.php

<?php
namespace App\Validator\Constraints;

use Symfony\Component\Validator\Constraint;

/**
* @Annotation
*/
class UniqueUsername extends Constraint
{
    public $message = 'The username "{{ value }}" is already in use in table {{ entity }}.';
}

src/Validator/Constraints/UniqueUsernameValidator.php

<?php

namespace App\Validator\Constraints;

use App\Entity\Foo;
use App\Entity\Bar;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Doctrine\ORM\EntityManagerInterface;

/**
 * Cross check for Bar <-> Foo if username exists in other table and if so add a validation error
 */
class UniqueUsernameValidator extends ConstraintValidator
{
    private $entityManager;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->entityManager = $entityManager;
    }

    public function validate($value, Constraint $constraint)
    {
        $username = $value;
        $entity = $this->context->getObject();
//        dd($username, $entity, get_class($entity));

        if ("App\Entity\Bar" == get_class($entity)) {
            $Foo = $this->entityManager->getRepository(Foo::class)->findOneBy(['username' => $username]);

            if ($Foo) {
                // If the check fails, use the following method to add a validation error to the field
                $this->context->buildViolation($constraint->message)
                    ->setParameter('{{ value }}', $value)
                    ->setParameter('{{ entity }}', 'Foo')
                    ->addViolation();
            }
        }

        if ("App\Entity\Foo" == get_class($entity)) {
            $Bar = $this->entityManager->getRepository(Bar::class)->findOneBy(['username' => $username]);

            if ($Bar) {
                // If the check fails, use the following method to add a validation error to the field
                $this->context->buildViolation($constraint->message)
                    ->setParameter('{{ value }}', $value)
                    ->setParameter('{{ entity }}', 'Bar')
                    ->addViolation();
            }
        }
    }
}

src/Entity/Foo.php

/**
 * @var string|null
 *
 * @ORM\Column(name="username", type="string", length=30, nullable=true, unique=true)
 *
 * Cross check if username already exists in entity "Bar":
 * @UniqueUsername
 */
private $username;

Repeat the same for entity "Bar"

Updated at 03/08/2024 15:15

https://www.ullright.org/ullWiki/show/symfony4-5-forms-cheatsheet

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