Taxonomy.php

<?php

namespace Drupal\taxonomy\Plugin\views\argument;

use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Drupal\views\Plugin\views\argument\NumericArgument;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Argument handler for basic taxonomy tid.
 *
 * @ingroup views_argument_handlers
 *
 * @ViewsArgument("taxonomy")
 */
class Taxonomy extends NumericArgument implements ContainerFactoryPluginInterface {
    
    /**
     * @var \Drupal\Core\Entity\EntityStorageInterface
     */
    protected $termStorage;
    
    /**
     * {@inheritdoc}
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityStorageInterface $term_storage) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->termStorage = $term_storage;
    }
    
    /**
     * {@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')
            ->getStorage('taxonomy_term'));
    }
    
    /**
     * Override the behavior of title(). Get the title of the node.
     */
    public function title() {
        // There might be no valid argument.
        if ($this->argument) {
            $term = $this->termStorage
                ->load($this->argument);
            if (!empty($term)) {
                return $term->getName();
            }
        }
        // TODO review text
        return $this->t('No name');
    }

}