Define Form Field with Priority in Symfony 8

In Symfony applications, form fields are displayed in the same sequence in which they are added inside the form type class. In more advanced scenarios - especially when fields are appended dynamically using form events - the final rendering order may not always be ideal. This tutorial explains how to define form field with priority in Symfony 8 application.

Symfony provides a built-in solution for controlling field position: the priority option. This option allows explicit ordering of form elements without changing the logical structure of the form definition.

Let's say we have a simple Task entity:

src/Entity/Task.php

<?php

namespace App\Entity;

class Task
{
    private string $title;

    private string $description;

    public function getTitle(): string { return $this->title; }
    public function setTitle(string $title): void { $this->title = $title; }

    public function getDescription(): string { return $this->description; }
    public function setDescription(string $description): void { $this->description = $description; }
}

The priority value is an integer. It can be positive or negative, and its default value is 0. Fields with higher values are rendered before those with lower values. When two fields share the same priority, their original order is preserved.

In the following example, the description field is defined first, followed by title. However, since the title field has a priority of 1 and description uses the default priority 0, the title field will be displayed before description when the form is rendered.

src/Form/Type/TaskType.php

<?php

namespace App\Form\Type;

use App\Entity\Task;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\Extension\Core\Type\TextareaType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class TaskType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder
            ->add('description', TextareaType::class)
            ->add('title', TextType::class, ['priority' => 1])
            ->add('save', SubmitType::class);
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults(['data_class' => Task::class]);
    }
}

Here is the controller that creates and renders the form in a standard way for testing:

src/Controller/TestController.php

<?php

namespace App\Controller;

use App\Entity\Task;
use App\Form\Type\TaskType;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Attribute\Route;

class TestController extends AbstractController
{
    #[Route('/')]
    public function index(): Response
    {
        $task = new Task();
        $form = $this->createForm(TaskType::class, $task);

        return $this->render('test/index.html.twig', ['fview' => $form]);
    }
}

templates/test/index.html.twig

{{ form(fview) }}