Block.php

<?php

namespace Drupal\arti_custom\Plugin\Block;

use Drupal\Core\Block\BlockBase;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a 'ContactsBlock' block.
 *
 * @Block(
 *  id = "arti_contacts",
 *  admin_label = @Translation("Contacts"),
 * )
 */
class ContactsBlock extends BlockBase implements ContainerFactoryPluginInterface {

  const INSTITUTE_SETTINGS = 'arti_custom.institute';
  /**
   * Drupal\Core\Config\ConfigFactoryInterface definition.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * Drupal\Core\Render\RendererInterface definition.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    $instance = new static($configuration, $plugin_id, $plugin_definition);
    $instance->configFactory = $container->get('config.factory');
    $instance->renderer = $container->get('renderer');
    return $instance;
  }

  /**
   * {@inheritdoc}
   */
  public function build() {
    $instituteConfig = $this->configFactory->get(static::INSTITUTE_SETTINGS);
    $build = [];
    $build['#attributes']['class'] = ['check-class--arti_contacts'];
    $build['content']['#theme'] = 'arti_contacts';
    $build['content']['#address'] = $instituteConfig->get('address');
    $build['content']['#email'] = $instituteConfig->get('email');
    $build['content']['#global_tel'] = $instituteConfig->get('telephones.global');
    $build['content']['#fax_tel'] = $instituteConfig->get('telephones.fax');

    $build['#contextual_links']['arti'] = [
      'route_parameters' => [],
    ];
    $this->renderer->addCacheableDependency($build['content'], $instituteConfig);
    return $build;
  }

}