AttributeClassDiscoveryAutomatedProviders.php

<?php

declare (strict_types=1);
namespace Drupal\migrate\Plugin\Discovery;

use Drupal\Component\Plugin\Attribute\AttributeInterface;
use Drupal\Core\Plugin\Discovery\AttributeClassDiscovery;
use Drupal\migrate\Attribute\MultipleProviderAttributeInterface;

/**
 * Determines providers based on the namespaces of a class and its ancestors.
 *
 * @internal
 *   This is a temporary solution to the fact that migration source plugins have
 *   more than one provider. This functionality will be moved to core in
 *   https://www.drupal.org/node/2786355.
 */
class AttributeClassDiscoveryAutomatedProviders extends AttributeClassDiscovery {
    
    /**
     * Prepares the attribute definition.
     *
     * @param \Drupal\Component\Plugin\Attribute\AttributeInterface $attribute
     *   The attribute derived from the plugin.
     * @param string $class
     *   The class used for the plugin.
     *
     * @throws \LogicException
     *   When the attribute class does not allow for multiple providers.
     */
    protected function prepareAttributeDefinition(AttributeInterface $attribute, string $class) : void {
        if (!$attribute instanceof MultipleProviderAttributeInterface) {
            throw new \LogicException('AttributeClassDiscoveryAutomatedProviders must implement ' . MultipleProviderAttributeInterface::class);
        }
        // @see Drupal\Component\Plugin\Discovery\AttributeClassDiscovery::prepareAttributeDefinition()
        $attribute->setClass($class);
        // Loop through all the parent classes and add their providers (which we
        // infer by parsing their namespaces) to the $providers array.
        $providers = $attribute->getProviders();
        do {
            $providers[] = $this->getProviderFromNamespace($class);
        } while (($class = get_parent_class($class)) !== FALSE);
        $providers = array_diff(array_unique(array_filter($providers)), [
            'component',
        ]);
        $attribute->setProviders($providers);
    }

}