diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 61e3701..0fe58ed 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -195,13 +195,9 @@ function book_menu() {
   );
   $items['node/%node/outline'] = array(
     'title' => 'Outline',
-    'page callback' => 'book_outline',
-    'page arguments' => array(1),
-    'access callback' => '_book_outline_access',
-    'access arguments' => array(1),
+    'route_name' => 'book_outline',
     'type' => MENU_LOCAL_TASK,
     'weight' => 2,
-    'file' => 'book.pages.inc',
   );
   $items['node/%node/outline/remove'] = array(
     'title' => 'Remove from outline',
@@ -250,20 +246,8 @@ function _book_outline_access(EntityInterface $node) {
  * @see book_menu()
  */
 function _book_outline_remove_access(EntityInterface $node) {
-  return _book_node_is_removable($node) && _book_outline_access($node);
-}
-
-/**
- * Determines if a node can be removed from the book.
- *
- * A node can be removed from a book if it is actually in a book and it either
- * is not a top-level page or is a top-level page with no children.
- *
- * @param \Drupal\Core\Entity\EntityInterface $node
- *   The node to remove from the outline.
- */
-function _book_node_is_removable(EntityInterface $node) {
-  return (!empty($node->book['bid']) && (($node->book['bid'] != $node->nid) || !$node->book['has_children']));
+  return Drupal::service('book.manager')->bookNodeIsRemovable($node)
+    && _book_outline_access($node);
 }
 
 /**
@@ -302,6 +286,9 @@ function book_get_books() {
  * @see book_pick_book_nojs_submit()
  */
 function book_form_node_form_alter(&$form, &$form_state, $form_id) {
+  // Get BookManager service
+  $book_manager = Drupal::service('book.manager');
+
   $node = $form_state['controller']->getEntity();
   $access = user_access('administer book outlines');
   if (!$access) {
@@ -310,9 +297,8 @@ function book_form_node_form_alter(&$form, &$form_state, $form_id) {
       $access = TRUE;
     }
   }
-
   if ($access) {
-    _book_add_form_elements($form, $form_state, $node);
+    $book_manager->bookAddFormElements($form, $form_state, $node);
     // Since the "Book" dropdown can't trigger a form submission when
     // JavaScript is disabled, add a submit button to do that. book.admin.css hides
     // this button when JavaScript is enabled.
@@ -329,6 +315,15 @@ function book_form_node_form_alter(&$form, &$form_state, $form_id) {
 }
 
 /**
+ * Implements hook_form_BASE_FORM_ID_alter() for the book_outline form.
+ */
+function book_form_book_outline_alter(&$form, &$form_state, $form_id) {
+  // Dynamically set title
+  $node = reset($form_state['build_info']['args']);
+  drupal_set_title($node->label());
+}
+
+/**
  * Form submission handler for node_form().
  *
  * This handler is run when JavaScript is disabled. It triggers the form to
@@ -400,92 +395,6 @@ function _book_parent_select($book_link) {
 }
 
 /**
- * Builds the common elements of the book form for the node and outline forms.
- *
- * @param \Drupal\Core\Entity\EntityInterface $node
- *   The node whose form is being viewed.
- */
-function _book_add_form_elements(&$form, &$form_state, EntityInterface $node) {
-  // If the form is being processed during the Ajax callback of our book bid
-  // dropdown, then $form_state will hold the value that was selected.
-  if (isset($form_state['values']['book'])) {
-    $node->book = $form_state['values']['book'];
-  }
-
-  $form['book'] = array(
-    '#type' => 'details',
-    '#title' => t('Book outline'),
-    '#weight' => 10,
-    '#collapsed' => TRUE,
-    '#group' => 'advanced',
-    '#attributes' => array(
-      'class' => array('book-outline-form'),
-    ),
-    '#attached' => array(
-      'library' => array(array('book', 'drupal.book')),
-    ),
-    '#tree' => TRUE,
-  );
-  foreach (array('menu_name', 'mlid', 'nid', 'router_path', 'has_children', 'options', 'module', 'original_bid', 'parent_depth_limit') as $key) {
-    $form['book'][$key] = array(
-      '#type' => 'value',
-      '#value' => $node->book[$key],
-    );
-  }
-
-  $form['book']['plid'] = _book_parent_select($node->book);
-
-  // @see _book_admin_table_tree(). The weight may be larger than 15.
-  $form['book']['weight'] = array(
-    '#type' => 'weight',
-    '#title' => t('Weight'),
-    '#default_value' => $node->book['weight'],
-    '#delta' => max(15, abs($node->book['weight'])),
-    '#weight' => 5,
-    '#description' => t('Pages at a given level are ordered first by weight and then by title.'),
-  );
-  $options = array();
-  $nid = isset($node->nid) ? $node->nid : 'new';
-
-  if (isset($node->nid) && ($nid == $node->book['original_bid']) && ($node->book['parent_depth_limit'] == 0)) {
-    // This is the top level node in a maximum depth book and thus cannot be moved.
-    $options[$node->nid] = $node->label();
-  }
-  else {
-    foreach (book_get_books() as $book) {
-      $options[$book['nid']] = $book['title'];
-    }
-  }
-
-  if (user_access('create new books') && ($nid == 'new' || ($nid != $node->book['original_bid']))) {
-    // The node can become a new book, if it is not one already.
-    $options = array($nid => t('- Create a new book -')) + $options;
-  }
-  if (!$node->book['mlid']) {
-    // The node is not currently in the hierarchy.
-    $options = array(0 => t('- None -')) + $options;
-  }
-
-  // Add a drop-down to select the destination book.
-  $form['book']['bid'] = array(
-    '#type' => 'select',
-    '#title' => t('Book'),
-    '#default_value' => $node->book['bid'],
-    '#options' => $options,
-    '#access' => (bool) $options,
-    '#description' => t('Your page will be a part of the selected book.'),
-    '#weight' => -5,
-    '#attributes' => array('class' => array('book-title-select')),
-    '#ajax' => array(
-      'callback' => 'book_form_update',
-      'wrapper' => 'edit-book-plid-wrapper',
-      'effect' => 'fade',
-      'speed' => 'fast',
-    ),
-  );
-}
-
-/**
  * Renders a new parent page select element when the book selection changes.
  *
  * This function is called via Ajax when the selected book is changed on a node
@@ -871,6 +780,9 @@ function book_node_predelete(EntityInterface $node) {
  * Implements hook_node_prepare().
  */
 function book_node_prepare(EntityInterface $node) {
+  // Get BookManager service
+  $book_manager = Drupal::service('book.manager');
+
   // Prepare defaults for the add/edit form.
   if (empty($node->book) && (user_access('add content to books') || user_access('administer book outlines'))) {
     $node->book = array();
@@ -886,7 +798,8 @@ function book_node_prepare(EntityInterface $node) {
       }
     }
     // Set defaults.
-    $node->book += _book_link_defaults(!empty($node->nid) ? $node->nid : 'new');
+    $node_ref = !empty($node->nid) ? $node->nid : 'new';
+    $node->book += $book_manager->bookLinkDefaults($node_ref);
   }
   else {
     if (isset($node->book['bid']) && !isset($node->book['original_bid'])) {
@@ -895,24 +808,11 @@ function book_node_prepare(EntityInterface $node) {
   }
   // Find the depth limit for the parent select.
   if (isset($node->book['bid']) && !isset($node->book['parent_depth_limit'])) {
-    $node->book['parent_depth_limit'] = _book_parent_depth_limit($node->book);
+    $node->book['parent_depth_limit'] = $book_manager->bookParentDepthLimit($node->book);
   }
 }
 
 /**
- * Finds the depth limit for items in the parent select.
- *
- * @param $book_link
- *   A fully loaded menu link that is part of the book hierarchy.
- *
- * @return
- *   The depth limit for items in the parent select.
- */
-function _book_parent_depth_limit($book_link) {
-  return MENU_MAX_DEPTH - 1 - (($book_link['mlid'] && $book_link['has_children']) ? entity_get_controller('menu_link')->findChildrenRelativeDepth($book_link) : 0);
-}
-
-/**
  * Implements hook_form_FORM_ID_alter() for node_delete_confirm().
  *
  * Alters the confirm form for a single node deletion.
@@ -931,19 +831,6 @@ function book_form_node_delete_confirm_alter(&$form, $form_state) {
 }
 
 /**
- * Returns an array with default values for a book page's menu link.
- *
- * @param $nid
- *   The ID of the node whose menu link is being created.
- *
- * @return
- *   The default values for the menu link.
- */
-function _book_link_defaults($nid) {
-  return array('original_bid' => 0, 'menu_name' => '', 'nid' => $nid, 'bid' => 0, 'router_path' => 'node/%', 'plid' => 0, 'mlid' => 0, 'has_children' => 0, 'weight' => 0, 'module' => 'book', 'options' => array());
-}
-
- /**
  * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function book_preprocess_block(&$variables) {
diff --git a/core/modules/book/book.pages.inc b/core/modules/book/book.pages.inc
index 67c4c99..9486786 100644
--- a/core/modules/book/book.pages.inc
+++ b/core/modules/book/book.pages.inc
@@ -84,111 +84,17 @@ function book_export_html(EntityInterface $node) {
 }
 
 /**
- * Page callback: Shows the outline form for a single node.
- *
- * @param \Drupal\Core\Entity\EntityInterface $node
- *   The book node for which to show the outline.
- *
- * @return string
- *   A HTML-formatted string with the outline form for a single node.
- *
- * @see book_menu()
- */
-function book_outline(EntityInterface $node) {
-  drupal_set_title($node->label());
-  return drupal_get_form('book_outline_form', $node);
-}
-
-/**
- * Form constructor for the book outline form.
- *
- * Allows handling of all book outline operations via the outline tab.
- *
- * @param \Drupal\Core\Entity\EntityInterface $node
- *   The book node for which to show the outline.
- *
- * @see book_outline_form_submit()
- * @see book_remove_button_submit()
- * @ingroup forms
- */
-function book_outline_form($form, &$form_state, EntityInterface $node) {
-  if (!isset($node->book)) {
-    // The node is not part of any book yet - set default options.
-    $node->book = _book_link_defaults($node->nid);
-  }
-  else {
-    $node->book['original_bid'] = $node->book['bid'];
-  }
-
-  // Find the depth limit for the parent select.
-  if (!isset($node->book['parent_depth_limit'])) {
-    $node->book['parent_depth_limit'] = _book_parent_depth_limit($node->book);
-  }
-  $form['#node'] = $node;
-  $form['#id'] = 'book-outline';
-  _book_add_form_elements($form, $form_state, $node);
-
-  $form['update'] = array(
-    '#type' => 'submit',
-    '#value' => $node->book['original_bid'] ? t('Update book outline') : t('Add to book outline'),
-    '#weight' => 15,
-  );
-
-  $form['remove'] = array(
-    '#type' => 'submit',
-    '#value' => t('Remove from book outline'),
-    '#access' => _book_node_is_removable($node),
-    '#weight' => 20,
-    '#submit' => array('book_remove_button_submit'),
-  );
-
-  return $form;
-}
-
-/**
  * Form submission handler for book_outline_form().
  *
  * Redirects to removal confirmation form.
  *
- * @see book_outline_form_submit()
+ * @see \Drupal\book\Form\BookOutlineForm::buildForm()
  */
 function book_remove_button_submit($form, &$form_state) {
   $form_state['redirect'] = 'node/' . $form['#node']->nid . '/outline/remove';
 }
 
 /**
- * Form submission handler for book_outline_form().
- *
- * @see book_remove_button_submit()
- */
-function book_outline_form_submit($form, &$form_state) {
-  $node = $form['#node'];
-  $form_state['redirect'] = "node/" . $node->nid;
-  $book_link = $form_state['values']['book'];
-  if (!$book_link['bid']) {
-    drupal_set_message(t('No changes were made'));
-
-    return;
-  }
-
-  $book_link['menu_name'] = book_menu_name($book_link['bid']);
-  $node->book = $book_link;
-  if (_book_update_outline($node)) {
-    if ($node->book['parent_mismatch']) {
-      // This will usually only happen when JS is disabled.
-      drupal_set_message(t('The post has been added to the selected book. You may now position it relative to other pages.'));
-      $form_state['redirect'] = "node/" . $node->nid . "/outline";
-    }
-    else {
-      drupal_set_message(t('The book outline has been updated.'));
-    }
-  }
-  else {
-    drupal_set_message(t('There was an error adding the post to the book.'), 'error');
-  }
-}
-
-/**
  * Form constructor to confirm removal of a node from a book.
  *
  * @param \Drupal\Core\Entity\EntityInterface $node
@@ -217,7 +123,7 @@ function book_remove_form($form, &$form_state, EntityInterface $node) {
  */
 function book_remove_form_submit($form, &$form_state) {
   $node = $form['#node'];
-  if (_book_node_is_removable($node)) {
+  if (Drupal::service('book.manager')->bookNodeIsRemovable($node)) {
     menu_link_delete($node->book['mlid']);
     db_delete('book')
       ->condition('nid', $node->nid)
diff --git a/core/modules/book/book.routing.yml b/core/modules/book/book.routing.yml
index 6c8b010..9c501fe 100644
--- a/core/modules/book/book.routing.yml
+++ b/core/modules/book/book.routing.yml
@@ -18,3 +18,10 @@ book_settings:
     _form: 'Drupal\book\BookSettingsForm'
   requirements:
     _permission: 'administer site configuration'
+
+book_outline:
+  pattern: 'node/{node}/outline'
+  defaults:
+    _form: 'Drupal\book\Form\BookOutlineForm'
+  requirements:
+    _permission: 'administer book outlines'
diff --git a/core/modules/book/lib/Drupal/book/BookManager.php b/core/modules/book/lib/Drupal/book/BookManager.php
index b037429..e093f49 100644
--- a/core/modules/book/lib/Drupal/book/BookManager.php
+++ b/core/modules/book/lib/Drupal/book/BookManager.php
@@ -8,6 +8,7 @@
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Entity\EntityManager;
+use Drupal\Core\Entity\EntityInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -94,4 +95,129 @@ protected function loadBooks() {
     }
   }
 
+  /**
+   * Returns an array with default values for a book page's menu link.
+   *
+   * @param $nid
+   *   The ID of the node whose menu link is being created.
+   *
+   * @return
+   *   The default values for the menu link.
+   */
+  public function bookLinkDefaults($nid) {
+    return array('original_bid' => 0, 'menu_name' => '', 'nid' => $nid,
+      'bid' => 0, 'router_path' => 'node/%', 'plid' => 0, 'mlid' => 0,
+      'has_children' => 0, 'weight' => 0, 'module' => 'book',
+      'options' => array());
+  }
+
+  /**
+   * Finds the depth limit for items in the parent select.
+   *
+   * @param $book_link
+   *   A fully loaded menu link that is part of the book hierarchy.
+   *
+   * @return
+   *   The depth limit for items in the parent select.
+   */
+  public function bookParentDepthLimit($book_link) {
+    return MENU_MAX_DEPTH - 1 - (($book_link['mlid'] && $book_link['has_children']) ? entity_get_controller('menu_link')->findChildrenRelativeDepth($book_link) : 0);
+  }
+
+  /**
+   * Builds the common elements of the book form for the node and outline forms.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $node
+   *   The node whose form is being viewed.
+   */
+  public function bookAddFormElements(&$form, &$form_state, EntityInterface $node) {
+    // If the form is being processed during the Ajax callback of our book bid
+    // dropdown, then $form_state will hold the value that was selected.
+    if (isset($form_state['values']['book'])) {
+      $node->book = $form_state['values']['book'];
+    }
+    $form['book'] = array(
+      '#type' => 'details',
+      '#title' => t('Book outline'),
+      '#weight' => 10,
+      '#collapsed' => TRUE,
+      '#group' => 'advanced',
+      '#attributes' => array(
+        'class' => array('book-outline-form'),
+      ),
+      '#attached' => array(
+        'library' => array(array('book', 'drupal.book')),
+      ),
+      '#tree' => TRUE,
+    );
+    foreach (array('menu_name', 'mlid', 'nid', 'router_path', 'has_children', 'options', 'module', 'original_bid', 'parent_depth_limit') as $key) {
+      $form['book'][$key] = array(
+        '#type' => 'value',
+        '#value' => $node->book[$key],
+      );
+    }
+
+    $form['book']['plid'] = _book_parent_select($node->book);
+
+    // @see _book_admin_table_tree(). The weight may be larger than 15.
+    $form['book']['weight'] = array(
+      '#type' => 'weight',
+      '#title' => t('Weight'),
+      '#default_value' => $node->book['weight'],
+      '#delta' => max(15, abs($node->book['weight'])),
+      '#weight' => 5,
+      '#description' => t('Pages at a given level are ordered first by weight and then by title.'),
+    );
+    $options = array();
+    $nid = isset($node->nid) ? $node->nid : 'new';
+    if (isset($node->nid) && ($nid == $node->book['original_bid']) && ($node->book['parent_depth_limit'] == 0)) {
+      // This is the top level node in a maximum depth book and thus cannot be moved.
+      $options[$node->nid] = $node->label();
+    }
+    else {
+      foreach (book_get_books() as $book) {
+        $options[$book['nid']] = $book['title'];
+      }
+    }
+
+    if (user_access('create new books') && ($nid == 'new' || ($nid != $node->book['original_bid']))) {
+      // The node can become a new book, if it is not one already.
+      $options = array($nid => t('- Create a new book -')) + $options;
+    }
+    if (!$node->book['mlid']) {
+      // The node is not currently in the hierarchy.
+      $options = array(0 => t('- None -')) + $options;
+    }
+
+    // Add a drop-down to select the destination book.
+    $form['book']['bid'] = array(
+      '#type' => 'select',
+      '#title' => t('Book'),
+      '#default_value' => $node->book['bid'],
+      '#options' => $options,
+      '#access' => (bool) $options,
+      '#description' => t('Your page will be a part of the selected book.'),
+      '#weight' => -5,
+      '#attributes' => array('class' => array('book-title-select')),
+      '#ajax' => array(
+        'callback' => 'book_form_update',
+        'wrapper' => 'edit-book-plid-wrapper',
+        'effect' => 'fade',
+        'speed' => 'fast',
+      ),
+    );
+  }
+
+  /**
+   * Determines if a node can be removed from the book.
+   *
+   * A node can be removed from a book if it is actually in a book and it either
+   * is not a top-level page or is a top-level page with no children.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $node
+   *   The node to remove from the outline.
+   */
+  public function bookNodeIsRemovable(EntityInterface $node) {
+    return (!empty($node->book['bid']) && (($node->book['bid'] != $node->nid) || !$node->book['has_children']));
+  }
 }
diff --git a/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
new file mode 100644
index 0000000..9cbfcfa
--- /dev/null
+++ b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
@@ -0,0 +1,124 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\book\Form\BasicSettingsForm.
+ */
+
+namespace Drupal\book\Form;
+
+use Drupal\Core\ControllerInterface;
+use Drupal\Core\Form\FormInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\book\BookManager;
+use Drupal\Core\Entity\EntityBCDecorator;
+
+/**
+ * Displays the book outline form.
+ */
+class BookOutlineForm implements ControllerInterface, FormInterface {
+
+  /**
+   * BookManager service
+   * @var Drupal\book\BookManager
+   */
+  protected $bookManager;
+
+  /**
+   * Constructs a BookOutlineForm object.
+   */
+  public function __construct(BookManager $bookManager) {
+    $this->bookManager = $bookManager;
+  }
+
+  /**
+   * This method lets us inject the services this class needs.
+   *
+   * Only inject services that are actually needed. Which services
+   * are needed will vary by the controller.
+   */
+  public static function create(ContainerInterface $container) {
+    return new static($container->get('book.manager'));
+  }
+
+  /**
+   * Implements \Drupal\Core\Form\FormInterface::getFormID().
+   */
+  public function getFormID() {
+    return 'book_outline';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, array &$form_state, EntityBCDecorator $node = NULL) {
+    if (!isset($node->book)) {
+      // The node is not part of any book yet - set default options.
+      $node->book = $this->bookManager->bookLinkDefaults($node->nid);
+    }
+    else {
+      $node->book['original_bid'] = $node->book['bid'];
+    }
+
+    // Find the depth limit for the parent select.
+    if (!isset($node->book['parent_depth_limit'])) {
+      $node->book['parent_depth_limit'] = $this->bookManager->bookParentDepthLimit($node->book);
+    }
+    $form['#node'] = $node;
+    $form['#id'] = 'book-outline';
+    $this->bookManager->bookAddFormElements($form, $form_state, $node);
+
+    $form['update'] = array(
+      '#type' => 'submit',
+      '#value' => $node->book['original_bid'] ? t('Update book outline') : t('Add to book outline'),
+      '#weight' => 15,
+    );
+
+    $form['remove'] = array(
+      '#type' => 'submit',
+      '#value' => t('Remove from book outline'),
+      '#access' => $this->bookManager->bookNodeIsRemovable($node),
+      '#weight' => 20,
+      '#submit' => array('book_remove_button_submit'),
+    );
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateForm(array &$form, array &$form_state) {}
+
+  /**
+   * {@inheritdoc}
+   *
+   * @see book_remove_button_submit()
+   */
+  public function submitForm(array &$form, array &$form_state) {
+    $node = $form['#node'];
+    $form_state['redirect'] = "node/" . $node->nid;
+    $book_link = $form_state['values']['book'];
+    if (!$book_link['bid']) {
+      drupal_set_message(t('No changes were made'));
+
+      return;
+    }
+
+    $book_link['menu_name'] = book_menu_name($book_link['bid']);
+    $node->book = $book_link;
+    if (_book_update_outline($node)) {
+      if ($node->book['parent_mismatch']) {
+        // This will usually only happen when JS is disabled.
+        drupal_set_message(t('The post has been added to the selected book. You may now position it relative to other pages.'));
+        $form_state['redirect'] = "node/" . $node->nid . "/outline";
+      }
+      else {
+        drupal_set_message(t('The book outline has been updated.'));
+      }
+    }
+    else {
+      drupal_set_message(t('There was an error adding the post to the book.'), 'error');
+    }
+  }
+}