farm-2.x-dev/modules/core/asset/src/AssetTypeListBuilder.php

<?php

namespace Drupal\asset;

use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Url;

/**
 * Provides a listing of asset type entities.
 */
class AssetTypeListBuilder extends ConfigEntityListBuilder {

  /**
   * {@inheritdoc}
   */
  public function buildHeader() {
    $header['label'] = $this->t('Asset type');
    $header['id'] = $this->t('Machine name');
    return $header + parent::buildHeader();
  }

  /**
   * {@inheritdoc}
   */
  public function buildRow(EntityInterface $entity) {
    $row['label'] = $entity->label();
    $row['id'] = $entity->id();
    // You probably want a few more properties here...
    return $row + parent::buildRow($entity);
  }

  /**
   * {@inheritdoc}
   */
  public function getDefaultOperations(EntityInterface $entity) {
    $operations = parent::getDefaultOperations($entity);
    // Place the edit operation after the operations added by field_ui.module
    // which have the weights 15, 20, 25.
    if (isset($operations['edit'])) {
      $operations['edit']['weight'] = 30;
    }
    return $operations;
  }

  /**
   * {@inheritdoc}
   */
  public function render() {
    $build = parent::render();
    $build['table']['#empty'] = $this->t('No asset types available. <a href=":link">Add asset type</a>.', [
      ':link' => Url::fromRoute('entity.asset_type.add_form')->toString(),
    ]);
    return $build;
  }

}