AutocompleteEntityFilterType.php

<?php

namespace App\Form\Filter\Type;

use EasyCorp\Bundle\EasyAdminBundle\Form\EventListener\CrudAutocompleteSubscriber;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\DataMapperInterface;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\OptionsResolver\OptionsResolver;

class AutocompleteEntityFilterType extends AbstractType implements DataMapperInterface
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->addEventSubscriber(new CrudAutocompleteSubscriber())
            ->setDataMapper($this)
        ;
    }

    public function finishView(FormView $view, FormInterface $form, array $options)
    {
        // Add a custom block prefix to inner field to ease theming:
        array_splice($view['autocomplete']->vars['block_prefixes'], -1, 0, 'ea_autocomplete_inner');

        // allowClear option needs a placeholder value (it can be empty)
        if (($view->vars['attr']['data-allow-clear'] ?? false) && (!isset($view->vars['attr']['data-placeholder']))) {
            $view->vars['attr']['data-placeholder'] = '';
        }
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'multiple' => false,
            // force display errors on this form field
            'error_bubbling' => false,
            'placeholder' => '',
        ]);

        $resolver->setRequired(['class']);
    }

    public function getBlockPrefix(): string
    {
        return 'ea_autocomplete';
    }

    public function mapDataToForms($viewData, $forms)
    {
        $form = current(iterator_to_array($forms, false));
        $form->setData($viewData);
    }

    public function mapFormsToData($forms, &$viewData)
    {
        $form = current(iterator_to_array($forms, false));
        $viewData = $form->getData();
    }
}

EntityFilterConfigurator.php

<?php

namespace App\EasyAdmin\Filter\Configurator;

use App\Form\Filter\Type\AutocompleteEntityFilterType;
use EasyCorp\Bundle\EasyAdminBundle\Config\Option\EA;
use EasyCorp\Bundle\EasyAdminBundle\Context\AdminContext;
use EasyCorp\Bundle\EasyAdminBundle\Contracts\Filter\FilterConfiguratorInterface;
use EasyCorp\Bundle\EasyAdminBundle\Dto\EntityDto;
use EasyCorp\Bundle\EasyAdminBundle\Dto\FieldDto;
use EasyCorp\Bundle\EasyAdminBundle\Dto\FilterDto;
use EasyCorp\Bundle\EasyAdminBundle\Field\AssociationField;
use EasyCorp\Bundle\EasyAdminBundle\Filter\EntityFilter;
use EasyCorp\Bundle\EasyAdminBundle\Router\AdminUrlGenerator;

final class EntityFilterConfigurator implements FilterConfiguratorInterface
{
    private AdminUrlGenerator $adminUrlGenerator;

    public function __construct(AdminUrlGenerator $adminUrlGenerator)
    {
        $this->adminUrlGenerator = $adminUrlGenerator;
    }

    public function supports(
        FilterDto $filterDto,
        ?FieldDto $fieldDto,
        EntityDto $entityDto,
        AdminContext $context
    ): bool {
        return EntityFilter::class === $filterDto->getFqcn();
    }

    public function configure(
        FilterDto $filterDto,
        ?FieldDto $fieldDto,
        EntityDto $entityDto,
        AdminContext $context
    ): void {
        $propertyName = $filterDto->getProperty();
        if (!$entityDto->isAssociation($propertyName)) {
            return;
        }

        if ($fieldDto && $fieldDto->getCustomOption(AssociationField::OPTION_AUTOCOMPLETE)) {
            $doctrineMetadata = $entityDto->getPropertyMetadata($propertyName);
            $filterDto->setFormTypeOptionIfNotSet('value_type_options.attr.data-ea-widget', 'ea-autocomplete');

            $targetEntityFqcn = $doctrineMetadata->get('targetEntity');
            $targetCrudControllerFqcn = $context->getCrudControllers()->findCrudFqcnByEntityFqcn($targetEntityFqcn);

            if ($targetCrudControllerFqcn) {
                $filterDto->setFormTypeOptionIfNotSet('value_type', AutocompleteEntityFilterType::class);

                $autocompleteEndpointUrl = $this->adminUrlGenerator
                    ->set('page', 1)
                    ->setController($targetCrudControllerFqcn)
                    ->setAction('autocomplete')
                    ->setEntityId(null)
                    ->unset(EA::SORT)
                    ->set('autocompleteContext', [
                        EA::CRUD_CONTROLLER_FQCN => $context->getRequest()->query->get(EA::CRUD_CONTROLLER_FQCN),
                        'propertyName' => $propertyName,
                        'originatingPage' => $context->getCrud()->getCurrentAction(),
                    ])
                    ->generateUrl()
                ;
                $filterDto->setFormTypeOption(
                    'value_type_options.attr.data-ea-autocomplete-endpoint-url',
                    $autocompleteEndpointUrl
                );
            }
        }
    }
}

services.yaml

services:
    _defaults:
        autowire: true
        autoconfigure: true

    App\EasyAdmin\Filter\Configurator\:
        resource: '../../src/EasyAdmin/Filter/Configurator/*'
        exclude: '../../src/EasyAdmin/Filter/Configurator/Abstract*'

    App\EasyAdmin\Filter\Configurator\AutocompleteEntityFilterConfigurator:
        tags:
            - { name: ea.filter_configurator }

    App\EasyAdmin\Filter\Configurator\EntityFilterConfigurator:
        tags:
            - { name: ea.filter_configurator }