Read-only Symfony form field ~ Robert Basic, software developer making web applications better

The future me will be grateful for this post. I always get it wrong the first time.

To set a Symfony form field as a read-only, we can’t set the readonly attribute as an option on that field:

src/AppBundle/Form/FooType.php

<?php
declare(strict_types=1);

namespace AppBundle\Form;

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

class FooType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('title', TextType::class, [
                'readonly' => true,
            ]);
    }
}

This won’t work, and will give the The option "readonly" does not exist. Defined options are:... exception.

We need to set it as an attribute of that field:

src/AppBundle/Form/FooType.php

<?php
declare(strict_types=1);

namespace AppBundle\Form;

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

class FooType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('title', TextType::class, [
                'attr' => ['readonly' => true],
            ]);
    }
}

Happy hackin’!