--- /dev/null
+<?php
+
+namespace Drupal\aggregator\Plugin\views\argument;
+
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\views\Plugin\views\argument\NumericArgument;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Argument handler to accept an aggregator feed id.
+ *
+ * @ingroup views_argument_handlers
+ *
+ * @ViewsArgument("aggregator_fid")
+ */
+class Fid extends NumericArgument {
+
+ /**
+ * The entity manager service.
+ *
+ * @var \Drupal\Core\Entity\EntityManagerInterface
+ */
+ protected $entityManager;
+
+ /**
+ * Constructs a Drupal\Component\Plugin\PluginBase object.
+ *
+ * @param array $configuration
+ * A configuration array containing information about the plugin instance.
+ * @param string $plugin_id
+ * The plugin_id for the plugin instance.
+ * @param mixed $plugin_definition
+ * The plugin implementation definition.
+ * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+ * The entity manager.
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityManagerInterface $entity_manager) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+ $this->entityManager = $entity_manager;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+ return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity.manager'));
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function titleQuery() {
+ $titles = [];
+
+ $feeds = $this->entityManager->getStorage('aggregator_feed')->loadMultiple($this->value);
+ foreach ($feeds as $feed) {
+ $titles[] = $feed->label();
+ }
+ return $titles;
+ }
+
+}