Plugin not found

Question

I am overwriting the CommentBulkForm class in my module.

namespace Drupal\mymod\Plugin\views\field;

use Drupal\comment\Plugin\views\field\CommentBulkForm;

/**
 * Defines a custom comment operations bulk form element.
 *
 * @ViewsField("custom_comment_bulk_form")
 */
class CustomCommentBulkForm extends CommentBulkForm {

  /**
   * {@inheritdoc}
   */
  protected function emptySelectedMessage() {
    return $this->t('some other message.');
  }

}

This file is placed inside mymodule\src\Plugin\views\field. I overwrote the views.view.comment to look for this class. However, I get the following error when I try to load the comments view.

Drupal\Component\Plugin\Exception\PluginException: Plugin (custom_comment_bulk_form) instance class "Drupal\mymod\Plugin\views\field\custom_comment_bulk_form" does not exist. in Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass() (line 97 of /vagrant/web/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php).

What's wrong in the code?

Answer 1

1. For PSR-2 loading to work is important:

• Check namespace, folders are coherent. If your module is ahrq, ensure the namespace uses ahrq, and the folder it sits is ahrq/src/Plugin/views/field. Check the casing is respected just in case (lowercase/uppercase matters).

• Ensure the file is named CustomCommentBulkForm.php

2. Yeah, obvious, but have you cleared your cache?

Answer 2

Plugin (xxx) instance class "Drupal\mymod\Plugin\views\field\custom_comment_bulk_form" does not exist. in Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass()

This happens when you've references to that plugin and Drupal cannot find it.

First step is obviously to try to clear the caches (drush cr, in case of Redis - redis-cli flushall). Alternatively try truncating cache_discovery table where this reference is stored.

If the clear cache didn't work, others things that can be done:

• Identify and ensure the module using that plugin/namespace is enabled.
• Ensure class/plugin is defined in module's .services.yml file.
• Ensure no files are missing, no typos and permission are fine.
• Re-run composer install.
• Briefly check Composer's autoload values (such as vendor/composer/autoload* and vendor/composer/installed.json), whether it has the right paths (sometimes mixing different environments or copying/committing these files can mess up with the paths).
• If this happened after module upgrade: review existing release changes, bugs and patches that you're using. Sometimes the old patch could break the working module on the upgrade.
• Review code for any typos.
• Otherwise consider removing/disabling broken code (all the references), then clearing up caches (cache_discovery table), if it's not needed.