hoover.module

<?php

/**
 * @file
 * Contains hoover.module..
 */

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Template\Attribute;
use Drupal\node\Entity\NodeType;
use \Drupal\Core\Entity\EntityInterface;
use \Drupal\Core\Entity\Display\EntityViewDisplayInterface;

/**
 * Implements hook_help().
 */
function hoover_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the hoover module.
    case 'help.page.hoover':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Thomas.ltd Hoover module') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_theme().
 */
function hoover_theme() {
  return array(
    'hoover_media_block' => array(
      'variables' => array(
        'items' => NULL,
        //'plugin_id' => NULL,
      ),
      //'file' => 'search.pages.inc',
    ),
  );
}

function template_preprocess_hoover_media_block(&$variables) {
  $classes = array(
    'swiper-container-media-block',
    'swiper-hoover',
  );
  $variables['#attached']['library'][] = 'hoover/swiper_photos';
  $variables['attributes'] = new Attribute($variables['attributes']);
  $variables['attributes']->addClass($classes);
}

/**
 * Implements hook_entity_extra_field_info().
 */
function hoover_entity_extra_field_info() {
  $extra = array();

  foreach (NodeType::loadMultiple() as $bundle) {
    if($bundle->Id() == 'hoover') {
      // producing country
      $extra['node'][$bundle->Id()]['display']['producing_country'] = array(
        'label' => t('Producing country'),
        'description' => t('Producing country value'),
        'weight' => 100,
        'visible' => TRUE,
      );
    }

  }

  return $extra;
}

/**
 * Implements hook_ENTITY_TYPE_view().
 */
function hoover_node_view(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, $view_mode, $langcode) {
  if ($display->getComponent('producing_country')) {
    $build['producing_country'] = [
      '#type' => 'markup',
      '#markup' => '<span>Германия</span>',
    ];
  }
}