Drupal 8: How create a simple custom module for breadcrumbs: Example #1

4 Aug.2016
Own custom breadcrumb

When in front of me there was a task to make a simple site with breadcrumbs, which can show me the necessary view I started looking my familiar and beloved path_breadcrumbs. However, the module has been for drupal 7 only. So I had to quickly write my own module. Below is an example of how you can do it yourself. I tried to leave the necessary comments in the code. I hope this will help anyone :-)

File
easydrupal_breadcrumb.info.yml
name: EasyDrupal Breadcrumbs
type: module
description: Setting breadcrumbs for custom content types.
core: 8.x
package: Custom
File
easydrupal_breadcrumb.module
<?php
/**
* @file
* Contains easydrupal_breadcrumb.module.
*/
 
 
use Drupal\Core\Routing\RouteMatchInterface;
 
 
/**
* Implements hook_help().
*/
function easydrupal_breadcrumb_help($route_name, RouteMatchInterface $route_match) {
 switch ($route_name) {
   // Main module help for the easydrupal_breadcrumb module.
   case 'help.page.easydrupal_breadcrumb':
     $output = '';
     $output .= '<h3>' . t('About') . '</h3>';
     $output .= '<p>' . t('Setting breadcrumbs for custom content types') . '</p>';
     return $output;
 
 
   default:
 }
}
File
easydrupal_breadcrumb.services.yml
services:
 easydrupal_breadcrumb.breadcrumb:
   class: Drupal\easydrupal_breadcrumb\Breadcrumb\EasydrupalBreadcrumbBuilder
   tags:
    - { name: breadcrumb_builder, priority: 100 }
File
/src/Breadcrumb/EasydrupalBreadcrumbBuilder.php
<?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 EasydrupalBreadCrumbBuilder implements BreadcrumbBuilderInterface {
 /**
  * {@inheritdoc}
  */
 public function applies(RouteMatchInterface $attributes) {
   $parameters = $attributes->getParameters()->all();
   // I need my breadcrumbs for a few node types ONLY,
   // so it should be applied on node page ONLY.
   if (isset($parameters['node']) && !empty($parameters['node'])) {
     return TRUE;
   }
 }
 
 
 /**
  * {@inheritdoc}
  */
 public function build(RouteMatchInterface $route_match) {
   $breadcrumb = new Breadcrumb();
   $breadcrumb->addLink(Link::createFromRoute('Home', '<front>'));
 
   $node = \Drupal::routeMatch()->getParameter('node');
   $node_type = $node->bundle();
 
   switch ($node_type) {
     // If node type is "project"
     // I want to add as parent of breadcrumb my summary projects view.
     case 'project':
       $breadcrumb->addLink(Link::createFromRoute('Projects', 'view.portfolio.page_1'));
 
       break;
 
     // If node type is "article".
     // I want to add as parent of breadcrumb my summary articles view.
     case 'article':
       $breadcrumb->addLink(Link::createFromRoute('Articles', 'view.articles.page_1'));
 
       break;
   }
 
   // Don't forget to add cache control by a route,
   // otherwise you will surprice,
   // all breadcrumb will be the same for all pages.
   $breadcrumb->addCacheContexts(['route']);
 
   return $breadcrumb;
 }
 
}

Conclusion

In this example, I showed how to quickly make a simple module for yourself. This example can be easily changed, for example, show "Active menu trail". Or, for example, another reason if you don't want any large >100kb module for your site and you know how to do that yourself.

I hope the information in this article helpful. And of course, I would happy if you can provide the own solution in a comment below.

I think will be interesting also "How to create a simple custom module for breadcrumbs: Example #2" which has more real examples.

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