Issue #3212302 by devkinetic, kachinsky, netsliver, Damien Laguerre,...

use Drupal\Core\Form\FormStateInterface;

use Drupal\node\Entity\Node;

use Drupal\node\NodeInterface;

use Drupal\Core\Cache\Cache;

/**

 * Provides an 'AddToAny share' block.

 * @Block(

 *   id = "addtoany_block",

 *   admin_label = @Translation("AddToAny share buttons"),

 *   context_definitions = {

 *     "node" = @ContextDefinition("entity:node", required = FALSE, label = @Translation("Node"))

 *   }

 * )

 */

class AddToAnyBlock extends BlockBase {

   */

  public function build() {

    $build = [];

    $node_id = \Drupal::routeMatch()->getParameter('node');

    if (is_numeric($node_id)) {

      $node = Node::load($node_id);

    }

    $node = $this->getContextValue('node');

    $is_node = isset($node) && $node instanceof NodeInterface ? TRUE : FALSE;

    $is_node = ($node instanceof NodeInterface);

    $data = $is_node ? addtoany_create_entity_data($node) : addtoany_create_data();

    $block_options = [];

      '#universal_button_placement' => $data['universal_button_placement'],

      '#buttons_size'               => $block_options['buttons_size'],

      '#theme'                      => 'addtoany_standard',

      '#cache'                      => [

        'contexts' => ['url'],

      ],

    ];

    if ($is_node) {

    }

  }

  /**

   * {@inheritdoc}

   */

  public function getCacheContexts() {

    return Cache::mergeContexts(parent::getCacheContexts(), ['url']);

  }

}