LocalTaskAssignForm.php

<?php

namespace Drupal\tmgmt_local\Form;

use Drupal\Core\Entity\ContentEntityForm;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
use Drupal\user\Entity\User;
use Drupal\views\Views;

/**
 * Assign task confirmation form.
 */
class LocalTaskAssignForm extends ContentEntityForm {

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    parent::buildForm($form, $form_state);
    $roles = tmgmt_local_translator_roles();
    if (empty($roles)) {
      $this
        ->messenger()
        ->addWarning(t('No user role has the "provide translation services" permission. <a href="@url">Configure permissions</a> for the Drupal user module.', array(
        '@url' => URL::fromRoute('user.admin_permissions'),
      )));
    }
    $form['tuid'] = array(
      '#title' => t('Assign to'),
      '#type' => 'select',
      '#empty_option' => t('- Select user -'),
      '#options' => tmgmt_local_get_assignees_for_tasks([
        $this
          ->getEntity()
          ->id(),
      ]),
      '#required' => TRUE,
    );
    $form['actions']['#type'] = 'actions';
    $form['actions']['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Assign tasks'),
    );
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    parent::submitForm($form, $form_state);

    /** @var \Drupal\user\Entity\User $assignee */
    $assignee = User::load($form_state
      ->getValue('tuid'));

    /** @var \Drupal\tmgmt_local\LocalTaskInterface $task */
    $task = $this
      ->getEntity();
    $task
      ->assign($assignee);
    $task
      ->save();
    $this
      ->messenger()
      ->addStatus(t('Assigned @label to user @assignee_name.', array(
      '@label' => $task
        ->label(),
      '@assignee_name' => $assignee
        ->getAccountName(),
    )));
    $view = Views::getView('tmgmt_local_task_overview');
    $view
      ->initDisplay();
    $form_state
      ->setRedirect($view
      ->getUrl()
      ->getRouteName());
  }

}