<?php

public function deleteAction()
{
    $toDoId = $this->params()->fromRoute('id', -1);

    $toDo = $this->entityManager->getRepository(ToDo::class)->findOneById($toDoId);
    if ($toDo == null) {
        $this->getResponse()->setStatusCode(404);
        return;
    }

    $this->toDoManager->removeToDo($toDo);

    $this->redirect()->toUrl('/');
}