knowledge-8.x-1.x-dev/src/KnowledgeBreadcrumbBuilder.php

<?php

namespace Drupal\knowledge;

use Drupal\Core\Breadcrumb\Breadcrumb;
use Drupal\Core\Breadcrumb\BreadcrumbBuilderInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Link;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;

/**
 * Class to define the knowledge breadcrumb builder.
 */
class KnowledgeBreadcrumbBuilder implements BreadcrumbBuilderInterface {
  use StringTranslationTrait;

  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;

  /**
   * Constructs the KnowledgeBreadcrumbBuilder.
   *
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   */
  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
    $this->entityTypeManager = $entity_type_manager;
  }

  /**
   * {@inheritdoc}
   */
  public function applies(RouteMatchInterface $route_match) {
    return FALSE && $route_match->getParameter('entity');
  }

  /**
   * {@inheritdoc}
   */
  public function build(RouteMatchInterface $route_match) {
    $breadcrumb = new Breadcrumb();
    $breadcrumb->addCacheContexts(['route']);
    $breadcrumb->addLink(Link::createFromRoute($this->t('Home'), '<front>'));

    $entity = $route_match->getParameter('entity');
    $breadcrumb->addLink(new Link($entity->label(), $entity->toUrl()));
    $breadcrumb->addCacheableDependency($entity);

    return $breadcrumb;
  }

}