RoomCalendar.php

<?php

namespace Drupal\bebooking\Plugin\Block;

use Drupal\Core\Block\BlockBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Drupal\Core\Entity\EntityTypeManager;
use Drupal\Core\Entity\Query\QueryFactory;

/**
 * Provides a 'RoomCalendar' block.
 *
 * @Block(
 *  id = "room_calendar",
 *  admin_label = @Translation("Room calendar"),
 * )
 */
class RoomCalendar extends BlockBase implements ContainerFactoryPluginInterface {

  /**
   * Drupal\Core\Entity\EntityTypeManager definition.
   *
   * @var \Drupal\Core\Entity\EntityTypeManager
   */
  protected $entityTypeManager;
  /**
   * Drupal\Core\Entity\Query\QueryFactory definition.
   *
   * @var \Drupal\Core\Entity\Query\QueryFactory
   */
  protected $entityQuery;
  /**
   * Construct.
   *
   * @param array $configuration
   *   A configuration array containing information about the plugin instance.
   * @param string $plugin_id
   *   The plugin_id for the plugin instance.
   * @param string $plugin_definition
   *   The plugin implementation definition.
   */
  public function __construct(
        array $configuration,
        $plugin_id,
        $plugin_definition,
        EntityTypeManager $entity_type_manager, 
	QueryFactory $entity_query
  ) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->entityTypeManager = $entity_type_manager;
    $this->entityQuery = $entity_query;
  }
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager'),
      $container->get('entity.query')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    return [
         'color' => $this->t(''),
        ] + parent::defaultConfiguration();

 }

  /**
   * {@inheritdoc}
   */
  public function blockForm($form, FormStateInterface $form_state) {
    $form['color'] = [
      '#type' => 'color',
      '#title' => $this->t('Color'),
      '#description' => $this->t(''),
      '#default_value' => $this->configuration['color'],
      '#weight' => '0',
    ];

    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function blockSubmit($form, FormStateInterface $form_state) {
    $this->configuration['color'] = $form_state->getValue('color');
  }

  /**
   * {@inheritdoc}
   */
  public function build() {
    $build = [];
    $build['room_calendar_color']['#markup'] = '<p>' . $this->configuration['color'] . '</p>';

    return $build;
  }

}