Alter existing route to a different route for a specific content type node using RouteSubscriber

Question

I want to modify node edit of a specific content type node to a different route .

Eg : suppose i have a node edit page route as entity.node.edit_form (core feature) . And now i want to change this route to custom_module.edit_form when taking the node to edit .

I refered This which explains altering the existing route to a different route . It only says to route to a different url . It may not work in my case as node edit form will contain node id as parameter . Its not mentioning how routes can be placed in $route->setPath() though .

For eg: In custom_module/src/Routing/RouteSubscriber.php

/**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    // Change path '/user/login' to '/login'.
    if ($route = $collection->get('user.login')) {
      $route->setPath('/login');
    }
    // Always deny access to '/user/logout'.
    // Note that the second parameter of setRequirement() is a string.
    if ($route = $collection->get('user.logout')) {
      $route->setRequirement('_access', 'FALSE');
    }
  }

How can i do this ?

Answer 1

Hi i done this as follows : in RouteSubscriber.php :

<?php

namespace Drupal\module_name\Routing;

use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;

/**
 * Listens to the dynamic route events.
 */
class RouteSubscriber extends RouteSubscriberBase {

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    // Change path '/node/edit' to custom controller action.
    if ($route = $collection->get('entity.node.edit_form')) {
        $route->setDefault('_controller', '\Drupal\module_name\Controller\MyController::alter_edit_route');
    }
  }
}    

and in MyController.php :

/**
 * Function to redirect the edit route to custom route
 */
public function alter_edit_route(){
    $node_id = \Drupal::routeMatch()->getRawParameter('node');
    //get the content type using node id 
    $entityObj  = entity_load('node',$node_id);
    $bundle = $entityObj->bundle();
    if($bundle=="custom_service_name"){
        //redirect to custom service list page
        $response = new RedirectResponse('/module_name/custom_service/'.$node_id);
        $response->send();
       return;
    }
    else return $this->redirect('entity.node.edit_form', ['node' => $node_id]);
}

NB:- A problem here is that its redirecting to the custom url for the specific content type . But when taking other content type nodes its hanging with the too many redirections.

Welcoming your insights on this . thanks .

UPDATE

Okay , here its how i resolved the problem . For the custom content type node its using the redirectResponse to redirect to custom page . For other content type nodes its creating the specific content type form and load the values to it for the specific node id . So in MyController.php

  /**
     * Function to redirect the edit route to custom route
     */
    public function alter_edit_route(){
        $node_id = \Drupal::routeMatch()->getRawParameter('node');
        //get the content type using node id 
        $entityObj  = entity_load('node',$node_id);
        $bundle = $entityObj->bundle();
        if($bundle=="custom_service_name"){
            //redirect to custom service list page
            $response = new RedirectResponse('/module_name/custom_service/'.$node_id);
            $response->send();
        }
        else {
            //programmatically load the node edit page with value
            $node = \Drupal::entityTypeManager()->getStorage('node')->load($node_id);
            $form = \Drupal::entityTypeManager()
              ->getFormObject('node', 'default')
              ->setEntity($node);
            return \Drupal::formBuilder()->getForm($form);
        }           
    }

Answer 2

You need to change the _controller for the route, check this code:

<?php

namespace Drupal\drush_help\Routing;

use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;

/**
 * Listens to the dynamic route events.
 */
class RouteSubscriber extends RouteSubscriberBase {

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    // Change the controller for the help page.
    if ($route = $collection->get('help.page')) {
      $route->setDefault('_controller', '\Drupal\drush_help\Controller\HelpController::helpPage');
    }
  }

}

In this case the route is altered to replace the Drupal help page for a custom controller.

If you want to see this in action go to check the code of the Drush Help module.

^{Disclosure: I'm the maintainer of the module Drush Help.}