Change the path used by a route dynamically

Question

Taxonomy terms have a canonical path of /taxonomy/term/{taxonomy_term} by default, which displays a View with content tagged with that term.

For certain taxonomies I would like to use a different view, dependent on the taxonomy bundle, so I can't just override the path entirely.

For example, "article" tags should link to /articles/{taxonomy_term}, "product" tags to /products/{taxonomy_term}.

My idea is to override the entity.taxonomy_term.canonical route adding some kind of callback that generates the path dynamically based on the taxonomy_term. Is this possible?

Answer 1

I don't believe that there is any need for custom route manipulation in your case, and besides, while I am not entirely sure, I don't think that something like what you describe, would actually work, since then you might have issues with the view's contextual filtering.

I believe the TVI Module is the answer to your problem. It can be used to specify the view/views that will be used in the vocabularies of your choice.

Answer 2

I used a path processor service to rewrite the outgoing paths for taxonomy terms that belong to a specific bundle.

Service definition:

services:
  my_module.path_processor:
    class: Drupal\my_module\Path\PathProcessor
    tags:
      - { name: path_processor_outbound, priority: 50 }

The processor class:

<?php

namespace Drupal\my_module\PathProcessor;

use Drupal\Core\PathProcessor\OutboundPathProcessorInterface;
use Drupal\Core\Render\BubbleableMetadata;
use Drupal\Core\Url;
use Symfony\Component\HttpFoundation\Request;

/**
 * Path processor to redirect taxonomy paths to a view with contextual arg.
 */
class TaxonomyPathProcessor implements OutboundPathProcessorInterface {

  /**
   * {@inheritdoc}
   */
  public function processOutbound($path, &$options = [], Request $request = NULL, BubbleableMetadata $bubbleable_metadata = NULL) {
    if (isset($options['entity_type'], $options['entity']) && $options['entity_type'] === 'taxonomy_term') {
      /** @var Drupal\taxonomy\Entity\Term $entity */
      $entity = $options['entity'];
      if ($entity->bundle() === 'article_tags') {
        $url = Url::fromRoute('view.articles.page_1', ['arg_0' => $entity->id()]);
        return $url->toString();
      }
    }

    return $path;
  }

}