ContextDelete.php

<?php

namespace Drupal\ctools\Form;

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Form\ConfirmFormBase;
use Drupal\Core\TempStore\SharedTempStoreFactory;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a form for deleting an contexts and relationships.
 */
abstract class ContextDelete extends ConfirmFormBase {
  
  /**
   * @var \Drupal\Core\TempStore\SharedTempStoreFactory
   */
  protected $tempstore;
  
  /**
   * @var string
   */
  protected $tempstore_id;
  
  /**
   * @var string
   */
  protected $machine_name;
  
  /**
   * The static context's machine name.
   *
   * @var string|array
   */
  protected $context_id;
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container->get('tempstore.shared'));
  }
  
  /**
   * Context Delete Constructor.
   *
   * @param \Drupal\Core\TempStore\SharedTempStoreFactory $tempstore
   *   Tempstore Service.
   */
  public function __construct(SharedTempStoreFactory $tempstore) {
    $this->tempstore = $tempstore;
  }
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'ctools_context_delete_form';
  }
  
  /**
   * {@inheritdoc}
   */
  public function getConfirmText() {
    return $this->t('Delete');
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state, $tempstore_id = NULL, $machine_name = NULL, $context_id = NULL) {
    $this->tempstore_id = $tempstore_id;
    $this->machine_name = $machine_name;
    $this->context_id = $context_id;
    return parent::buildForm($form, $form_state);
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $form_state->setRedirectUrl($this->getCancelUrl());
  }
  
  /**
   * Get a temp storage object.
   *
   * @return mixed
   *   The tempstore object.
   */
  protected function getTempstore() {
    return $this->tempstore
      ->get($this->tempstore_id)
      ->get($this->machine_name);
  }
  
  /**
   * Set the temp storage.
   *
   * @param array $cached_values
   *   Cached values to use in the tempstore.
   *
   * @throws \Drupal\Core\TempStore\TempStoreException
   */
  protected function setTempstore($cached_values) {
    $this->tempstore
      ->get($this->tempstore_id)
      ->set($this->machine_name, $cached_values);
  }

}