diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index 06e3cb2..5315722 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -141,6 +141,10 @@ function aggregator_menu() {
     'title' => 'Categories',
     'route_name' => 'aggregator.categories',
   );
+  $items['aggregator/opml'] = array(
+    'title' => 'OPML feed',
+    'route_name' => 'aggregator_opml',
+  );
   $items['aggregator/categories/%aggregator_category'] = array(
     'title callback' => '_aggregator_category_title',
     'title arguments' => array(2),
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index cd938e7..5032123 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -6,8 +6,87 @@
  */
 
 use Drupal\aggregator\Entity\Feed;
+use Symfony\Component\HttpFoundation\Response;
 use Drupal\Core\Entity\EntityInterface;
 
+
+/**
+ * Page callback: Displays all the items captured from the particular feed.
+ *
+ * @param \Drupal\aggregator\Entity\Feed $feed
+ *   The feed for which to display all items.
+ *
+ * @return string
+ *   The rendered list of items for the feed.
+ *
+ * @see aggregator_menu()
+ */
+function aggregator_page_source(Feed $feed) {
+  $feed_source = entity_view($feed, 'default');
+
+  // It is safe to include the fid in the query because it's loaded from the
+  // database by aggregator_feed_load().
+  $items = aggregator_load_feed_items('source', $feed);
+
+  return _aggregator_page_list($items, arg(3), $feed_source);
+}
+
+/**
+ * Form constructor to show all items captured from a feed.
+ *
+ * @param $feed
+ *   The feed for which to list all of the aggregated items.
+ *
+ * @return string
+ *   The rendered list of items for the feed.
+ *
+ * @see aggregator_menu()
+ * @see aggregator_page_source()
+ * @ingroup forms
+ */
+function aggregator_page_source_form($form, $form_state, $feed) {
+  return aggregator_page_source($feed);
+}
+
+/**
+ * Form constructor to list items aggregated in a category.
+ *
+ * @param $category
+ *   The category for which to list all of the aggregated items.
+ *
+ * @return string
+ *   The rendered list of items for the feed.
+ *
+ * @see aggregator_menu()
+ * @ingroup forms
+ */
+function aggregator_page_category($category) {
+  drupal_add_feed('aggregator/rss/' . $category->cid, Drupal::config('system.site')->get('name') . ' ' . t('aggregator - @title', array('@title' => $category->title)));
+
+  // It is safe to include the cid in the query because it's loaded from the
+  // database by aggregator_category_load().
+  $items = aggregator_load_feed_items('category', $category);
+
+  return _aggregator_page_list($items, arg(3));
+}
+
+/**
+ * Form constructor to list items aggregated in a category.
+ *
+ * @param $category
+ *   The category for which to list all of the aggregated items.
+ *
+ * @return string
+ *   The rendered list of items for the feed.
+ *
+ * @see aggregator_menu()
+ * @see aggregator_page_category()
+ * @ingroup forms
+ */
+function aggregator_page_category_form($form, $form_state, $category) {
+  return aggregator_page_category($category);
+}
+
 /**
  * Loads and optionally filters feed items.
  *
@@ -104,36 +183,6 @@ function template_preprocess_aggregator_item(&$variables) {
 }
 
 /**
- * Page callback: Generates an OPML representation of all feeds.
- *
- * @param $cid
- *   (optional) If set, feeds are exported only from a category with this ID.
- *   Otherwise, all feeds are exported. Defaults to NULL.
- *
- * @return string
- *   An OPML formatted string.
- *
- * @see aggregator_menu()
- *
- * @deprecated Use \Drupal\aggregator\Controller\AggregatorController::opmlPage()
- */
-function aggregator_page_opml($cid = NULL) {
-  if ($cid) {
-    $result = db_query('SELECT f.title, f.url FROM {aggregator_feed} f LEFT JOIN {aggregator_category_feed} c on f.fid = c.fid WHERE c.cid = :cid ORDER BY title', array(':cid' => $cid));
-  }
-  else {
-    $result = db_query('SELECT * FROM {aggregator_feed} ORDER BY title');
-  }
-
-  $feeds = $result->fetchAll();
-  $aggregator_page_opml = array(
-    '#theme' => 'aggregator_page_opml',
-    '#feeds' => $feeds,
-  );
-  return drupal_render($aggregator_page_opml);
-}
-
-/**
  * Prints the OPML page for the feed.
  *
  * @param array $variables
@@ -144,9 +193,8 @@ function aggregator_page_opml($cid = NULL) {
  */
 function theme_aggregator_page_opml($variables) {
   $feeds = $variables['feeds'];
-
-  drupal_add_http_header('Content-Type', 'text/xml; charset=utf-8');
-
+  $response = new Response();
+  $response->headers->set('Content-Type', 'text/xml; charset=utf-8');
   $output  = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
   $output .= "<opml version=\"1.1\">\n";
   $output .= "<head>\n";
diff --git a/core/modules/aggregator/aggregator.routing.yml b/core/modules/aggregator/aggregator.routing.yml
index e05c4d9..fc7d64c 100644
--- a/core/modules/aggregator/aggregator.routing.yml
+++ b/core/modules/aggregator/aggregator.routing.yml
@@ -147,3 +147,10 @@ aggregator.opml_page:
     cid: null
   requirements:
     _permission: 'access news feeds'
+
+aggregator_opml:
+    pattern: 'aggregator/opml'
+    defaults:
+      _controller: '\Drupal\aggregator\Controller\AggregatorController::opml'
+    requirements:
+      _permission: 'administer news feeds'
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
index bfbf5b0..6327773 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
@@ -23,6 +23,20 @@
 class AggregatorController extends ControllerBase implements ContainerInjectionInterface {
 
   /**
+   * Stores the Entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManager
+   */
+  protected $entityManager;
+
+  /**
+   * The configuration factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
    * The database connection.
    *
    * @var \Drupal\Core\Database\Connection;
@@ -353,4 +367,32 @@ public function opmlPage($cid = NULL) {
     return aggregator_page_opml($cid);
   }
 
+/**
+ * Generates an OPML representation of all feeds.
+ *
+ * @param \Drupal\aggregator\FeedInterface $aggregator_feed
+ *  (optional) If set, feeds are exported only from a category with this ID.
+ *   Otherwise, all feeds are exported. Defaults to NULL.
+ *
+ * @return array
+ *   A render array as expected by drupal_render().
+ */
+ public function opml(FeedInterface $aggregator_feed = NULL) {
+  if ($aggregator_feed) {
+     $result =  $this->database->query('SELECT f.title, f.url FROM {aggregator_feed} f LEFT JOIN {aggregator_category_feed} c on f.fid = c.fid WHERE c.cid = :cid ORDER BY title',
+       array(
+         ':cid' => $aggregator_feed,
+       )
+     );
+  }
+  else {
+    $result = $this->database->query(db_query('SELECT * FROM {aggregator_feed} ORDER BY title'));
+  }
+  $feeds = $result->fetchAllAssoc('title');
+  $aggregator_page_opml = array(
+    '#theme' => 'aggregator_page_opml',
+    '#feeds' => $feeds,
+  );
+  return $aggregator_page_opml;
+ }
 }