app/bundles/PageBundle/Controller/Api/PageApiController.php

<?php

namespace Mautic\PageBundle\Controller\Api;

use Doctrine\Persistence\ManagerRegistry;
use Mautic\ApiBundle\Controller\CommonApiController;
use Mautic\ApiBundle\Helper\EntityResultHelper;
use Mautic\CoreBundle\Factory\MauticFactory;
use Mautic\CoreBundle\Factory\ModelFactory;
use Mautic\CoreBundle\Helper\AppVersion;
use Mautic\CoreBundle\Helper\CoreParametersHelper;
use Mautic\CoreBundle\Helper\UserHelper;
use Mautic\CoreBundle\Security\Permissions\CorePermissions;
use Mautic\CoreBundle\Translation\Translator;
use Mautic\PageBundle\Entity\Page;
use Mautic\PageBundle\Model\PageModel;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\Form\FormFactoryInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\Routing\RouterInterface;

/**
 * @extends CommonApiController<Page>
 */
class PageApiController extends CommonApiController
{
    /**
     * @var PageModel|null
     */
    protected $model;

    public function __construct(CorePermissions $security, Translator $translator, EntityResultHelper $entityResultHelper, RouterInterface $router, FormFactoryInterface $formFactory, AppVersion $appVersion, RequestStack $requestStack, ManagerRegistry $doctrine, ModelFactory $modelFactory, EventDispatcherInterface $dispatcher, CoreParametersHelper $coreParametersHelper, MauticFactory $factory)
    {
        $pageModel = $modelFactory->getModel('page');
        \assert($pageModel instanceof PageModel);

        $this->model            = $pageModel;
        $this->entityClass      = Page::class;
        $this->entityNameOne    = 'page';
        $this->entityNameMulti  = 'pages';
        $this->serializerGroups = ['pageDetails', 'categoryList', 'publishDetails'];
        $this->dataInputMasks   = ['customHtml' => 'html'];

        parent::__construct($security, $translator, $entityResultHelper, $router, $formFactory, $appVersion, $requestStack, $doctrine, $modelFactory, $dispatcher, $coreParametersHelper, $factory);
    }

    /**
     * Obtains a list of pages.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function getEntitiesAction(Request $request, UserHelper $userHelper)
    {
        // get parent level only
        $this->listFilters[] = [
            'column' => 'p.variantParent',
            'expr'   => 'isNull',
        ];

        $this->listFilters[] = [
            'column' => 'p.translationParent',
            'expr'   => 'isNull',
        ];

        return parent::getEntitiesAction($request, $userHelper);
    }
}