Drupal 8 & 9: How create a simple custom module for breadcrumbs: Example #2

services:
  easydrupal_breadcrumb.breadcrumb_nodes:
    class: Drupal\easydrupal_breadcrumb\Breadcrumb\BreadcrumbNodesBuilder
    tags:
     - { name: breadcrumb_builder, priority: 100 }
  easydrupal_breadcrumb.breadcrumb_views:
    class: Drupal\easydrupal_breadcrumb\Breadcrumb\BreadcrumbViewsBuilder
    tags:
     - { name: breadcrumb_builder, priority: 100 }

<?php
 
namespace Drupal\easydrupal_breadcrumb\Breadcrumb;
 
use Drupal\Core\Breadcrumb\Breadcrumb;
use Drupal\Core\Breadcrumb\BreadcrumbBuilderInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Link;
use Drupal\node\NodeInterface;
 
class BreadcrumbNodesBuilder implements BreadcrumbBuilderInterface {
 
  /**
   * {@inheritdoc}
   */
  public function applies(RouteMatchInterface $attributes) {
    $parameters = $attributes->getParameters()->all();
    if (isset($parameters['node']) && $parameters['node'] instanceof NodeInterface) {
      return TRUE;
    }
  }
 
  /**
   * {@inheritdoc}
   */
  public function build(RouteMatchInterface $route_match) {
    $breadcrumb = new Breadcrumb();
 
    $node = \Drupal::routeMatch()->getParameter('node');
    $node_type = $node->bundle();
 
    switch ($node_type) {
 
      // If node type is "article".
      // I want to add as parent of breadcrumb my summary articles view.
      case 'article':
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
        $breadcrumb->addLink(Link::createFromRoute('News', 'entity.node.canonical', ['node' => '10360']));
 
        break;
 
      // If node type is "event"
      // I want to add as parent of breadcrumb my summary event view.
      case 'event':
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
        $breadcrumb->addLink(Link::createFromRoute('Events', 'entity.node.canonical', ['node' => '8085']));
 
        break;
 
      // If node type is "location / venue"
      // I want to add as parent of breadcrumb my Campus Map page.
      case 'location':
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
        $breadcrumb->addLink(Link::createFromRoute('Campus Map', 'entity.node.canonical', ['node' => '6']));
 
        break;
 
      // If node type is "person"
      // I want to add as parent of breadcrumb my Directory page.
      case 'person':
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
        $breadcrumb->addLink(Link::createFromRoute('Directory', 'view.a_z.page_1'));
 
        break;
      // If node type is "page"
      // I want to add custom breadcrumbs for few pages.
      case 'page':
 
        // Apply the custom breadcrumbs for News page.
        if ($node->id() == '10360') {
          $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
          $breadcrumb->addLink(Link::createFromRoute('About', 'entity.node.canonical', ['node' => '15220']));
        }
 
        break;
 
      default:
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
 
        break;
 
    }
 
    // Don't forget to add cache control,otherwise you will surprised,
    // all breadcrumb will be the same for all pages.
    // By setting a "cache context" to the "url", each requested URL gets it's
    // own cache. This way a single breadcrumb isn't cached for all pages on the
    // site.
    $breadcrumb->addCacheContexts(['url']);
 
    // By adding "cache tags" for this specific node, the cache is invalidated
    // when the node is edited.
    $breadcrumb->addCacheTags(["node:{$node->id()}"]);
 
    return $breadcrumb;
  }
 
}

<?php
 
namespace Drupal\easydrupal_breadcrumb\Breadcrumb;
 
use Drupal\Core\Breadcrumb\Breadcrumb;
use Drupal\Core\Breadcrumb\BreadcrumbBuilderInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Link;
 
class BreadcrumbViewsBuilder implements BreadcrumbBuilderInterface {
 
  /**
   * {@inheritdoc}
   */
  public function applies(RouteMatchInterface $attributes) {
    $parameters = $attributes->getParameters()->all();
    // I need my breadcrumbs for a few views ONLY.
    if (isset($parameters['view_id']) && !empty($parameters['view_id'])) {
      return TRUE;
    }
  }
 
  /**
   * {@inheritdoc}
   */
  public function build(RouteMatchInterface $route_match) {
    $breadcrumb = new Breadcrumb();
 
    $view_name = \Drupal::routeMatch()->getParameter('view_id');
 
    switch ($view_name) {
 
      case 'glossary':
        $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
        $breadcrumb->addLink(Link::createFromRoute('A-Z Index', '<nolink>'));
 
        break;
 
    }
 
    // Don't forget to add cache control by a route, otherwise you will surprised,
    // all breadcrumb will be the same for all pages.
    $breadcrumb->addCacheContexts(['route']);
 
    return $breadcrumb;
  }
 
}