Update to Drupal 8.1.1. For more information, see https://www.drupal.org/node/2718713

core/modules/views_ui/src/Form/Ajax/AddHandler.php

@@ -160,7 +160,7 @@ class AddHandler extends ViewsFormBase {
     }
     else {
       $form['options']['markup'] = array(
-        '#markup' => '<div class="js-form-item form-item">' . $this->t('There are no @types available to add.', array('@types' =>  $ltitle)) . '</div>',
+        '#markup' => '<div class="js-form-item form-item">' . $this->t('There are no @types available to add.', array('@types' => $ltitle)) . '</div>',
       );
     }
     // Add a div to show the selected items

core/modules/views_ui/src/Form/Ajax/ConfigHandlerExtra.php

@@ -53,7 +53,7 @@ class ConfigHandlerExtra extends ViewsFormBase {
 
     $form = array(
       'options' => array(
-        '#tree' => true,
+        '#tree' => TRUE,
         '#theme_wrappers' => array('container'),
         '#attributes' => array('class' => array('scroll'), 'data-drupal-views-scroll' => TRUE),
       ),

core/modules/views_ui/src/Form/Ajax/RearrangeFilter.php

@@ -352,4 +352,3 @@ class RearrangeFilter extends ViewsFormBase {
   }
 
 }
-

core/modules/views_ui/src/Form/Ajax/ViewsFormBase.php

@@ -3,17 +3,20 @@
 namespace Drupal\views_ui\Form\Ajax;
 
 use Drupal\Component\Utility\Html;
+use Drupal\Core\Ajax\AjaxResponse;
+use Drupal\Core\Ajax\CloseModalDialogCommand;
 use Drupal\Core\Ajax\OpenModalDialogCommand;
 use Drupal\Core\Form\FormBase;
 use Drupal\Core\Form\FormState;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\Render\RenderContext;
+use Drupal\views\Ajax\HighlightCommand;
+use Drupal\views\Ajax\ReplaceTitleCommand;
+use Drupal\views\Ajax\ShowButtonsCommand;
+use Drupal\views\Ajax\TriggerPreviewCommand;
 use Drupal\views\ViewEntityInterface;
-use Drupal\views\Ajax;
-use Drupal\views_ui\Ajax as AjaxUI;
-use Drupal\Core\Ajax\AjaxResponse;
-use Drupal\Core\Ajax\CloseModalDialogCommand;
+use Drupal\views_ui\Ajax\SetFormCommand;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
@@ -151,10 +154,10 @@ abstract class ViewsFormBase extends FormBase implements ViewsFormInterface {
     else {
       $response = new AjaxResponse();
       $response->addCommand(new CloseModalDialogCommand());
-      $response->addCommand(new Ajax\ShowButtonsCommand(!empty($view->changed)));
-      $response->addCommand(new Ajax\TriggerPreviewCommand());
+      $response->addCommand(new ShowButtonsCommand(!empty($view->changed)));
+      $response->addCommand(new TriggerPreviewCommand());
       if ($page_title = $form_state->get('page_title')) {
-        $response->addCommand(new Ajax\ReplaceTitleCommand($page_title));
+        $response->addCommand(new ReplaceTitleCommand($page_title));
       }
     }
     // If this form was for view-wide changes, there's no need to regenerate
@@ -248,10 +251,10 @@ abstract class ViewsFormBase extends FormBase implements ViewsFormInterface {
       // Usually this happens at the same path, but custom paths may be
       // specified in $form_state.
       $form_url = $form_state->has('url') ? $form_state->get('url')->toString() : $this->url('<current>');
-      $response->addCommand(new AjaxUI\SetFormCommand($form_url));
+      $response->addCommand(new SetFormCommand($form_url));
 
       if ($section = $form_state->get('#section')) {
-        $response->addCommand(new Ajax\HighlightCommand('.' . Html::cleanCssIdentifier($section)));
+        $response->addCommand(new HighlightCommand('.' . Html::cleanCssIdentifier($section)));
       }
 
       return $response;

core/modules/views_ui/src/Tests/CachedDataUITest.php

@@ -44,7 +44,7 @@ class CachedDataUITest extends UITestBase {
     // Test we are redirected to the view listing page.
     $this->assertUrl('admin/structure/views', array(), 'Redirected back to the view listing page.');
 
-    // Login with another user and make sure the view is locked and break.
+    // Log in with another user and make sure the view is locked and break.
     $this->drupalPostForm('admin/structure/views/nojs/display/test_view/default/title', array(), t('Apply'));
     $this->drupalLogin($this->adminUser);
 

core/modules/views_ui/src/Tests/FieldUITest.php

@@ -54,7 +54,7 @@ class FieldUITest extends UITestBase {
     $this->assertEqual((string) $result[2], '{{ name }} == Name');
 
     $result = $this->xpath('//details[@id="edit-options-more"]');
-    $this->assertEqual(empty($result), true, "Container 'more' is empty and should not be displayed.");
+    $this->assertEqual(empty($result), TRUE, "Container 'more' is empty and should not be displayed.");
   }
 
   /**

core/modules/views_ui/src/Tests/PreviewTest.php

@@ -107,7 +107,7 @@ class PreviewTest extends UITestBase {
     $this->assertText("SELECT views_test_data.name AS views_test_data_name\nFROM \n{views_test_data} views_test_data\nWHERE (( (views_test_data.id = '100' ) ))");
 
     // Test that the statistics and query are rendered above the preview.
-    $this->assertTrue(strpos($this->getRawContent(), 'views-query-info') < strpos($this->getRawContent(), 'view-test-preview') , 'Statistics shown above the preview.');
+    $this->assertTrue(strpos($this->getRawContent(), 'views-query-info') < strpos($this->getRawContent(), 'view-test-preview'), 'Statistics shown above the preview.');
 
     // Test that statistics and query rendered below the preview.
     $settings->set('ui.show.sql_query.where', 'below')->save();

core/modules/views_ui/src/Tests/RedirectTest.php

@@ -25,7 +25,7 @@ class RedirectTest extends UITestBase {
     $random_destination = $this->randomMachineName();
     $edit_path = "admin/structure/views/view/$view_name/edit";
 
-    $this->drupalPostForm($edit_path, array(), t('Save') , array('query' => array('destination' => $random_destination)));
+    $this->drupalPostForm($edit_path, array(), t('Save'), array('query' => array('destination' => $random_destination)));
     $this->assertUrl($random_destination, array(), 'Make sure the user got redirected to the expected page defined in the destination.');
 
     // Setup a view with a certain page display path. If you change the path

core/modules/views_ui/src/Tests/TranslatedViewTest.php

@@ -48,7 +48,7 @@ class TranslatedViewTest extends WebTestBase {
       'translate interface',
     ];
 
-    // Create and login user.
+    // Create and log in user.
     $this->adminUser = $this->drupalCreateUser($permissions);
     $this->drupalLogin($this->adminUser);
 

core/modules/views_ui/tests/src/FunctionalJavascript/LibraryCachingTest.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace Drupal\Tests\views_ui\FunctionalJavascript;
+
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+
+/**
+ * Tests the JavaScript library caching on consecutive requests.
+ *
+ * @group views_ui
+ */
+class LibraryCachingTest extends JavascriptTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['node', 'views', 'views_ui'];
+
+  /**
+   * Tests if the Views UI dialogs open on consecutive requests.
+   */
+  public function testConsecutiveDialogRequests() {
+    $admin_user = $this->drupalCreateUser([
+      'administer site configuration',
+      'administer views',
+      'administer nodes',
+      'access content overview',
+    ]);
+
+    // Disable automatic live preview to make the sequence of calls clearer.
+    \Drupal::configFactory()->getEditable('views.settings')->set('ui.always_live_preview', FALSE)->save();
+    $this->drupalLogin($admin_user);
+
+    $this->drupalGet('admin/structure/views/view/content');
+    $page = $this->getSession()->getPage();
+
+    // Use the 'Add' link for fields to open a dialog. This will load the proper
+    // dialog libraries.
+    $add_link = $page->findById('views-add-field');
+    $this->assertTrue($add_link->isVisible(), 'Add fields button found.');
+    $add_link->click();
+    $this->getSession()->wait(5000, "jQuery('.ui-dialog-titlebar').length > 0");
+    // Close the dialog and open it again. No no libraries will be loaded, but a
+    // cache entry will be made for not loading any libraries.
+    $page->pressButton('Close');
+    $add_link->click();
+    $this->getSession()->wait(5000, "jQuery('.ui-dialog-titlebar').length > 0");
+    $page->pressButton('Close');
+
+    // Reload the page.
+    $this->drupalGet('admin/structure/views/view/content');
+    $page = $this->getSession()->getPage();
+
+    // Now use the 'Update preview' button to load libraries.
+    $preview = $page->findById('preview-submit');
+    // The first click will load all the libraries.
+    $preview->click();
+    $this->getSession()->wait(5000, "jQuery('.ajax-progress').length === 0");
+    // The second click will not load any new libraries.
+    $preview->click();
+    $this->getSession()->wait(5000, "jQuery('.ajax-progress').length === 0");
+    // Check to see if the dialogs still open.
+    $add_link = $page->findById('views-add-field');
+    $add_link->click();
+    $this->getSession()->wait(5000, "jQuery('.ui-dialog-titlebar').length > 0");
+    $page->pressButton('Close');
+  }
+
+}

core/modules/views_ui/views_ui.module

@@ -270,7 +270,7 @@ function views_ui_contextual_links_suppress($set = NULL) {
  * @see views_ui_contextual_links_suppress_pop()
  */
 function views_ui_contextual_links_suppress_push() {
-  views_ui_contextual_links_suppress(((int) views_ui_contextual_links_suppress())+1);
+  views_ui_contextual_links_suppress(((int) views_ui_contextual_links_suppress()) + 1);
 }
 
 /**
@@ -279,7 +279,7 @@ function views_ui_contextual_links_suppress_push() {
  * @see views_ui_contextual_links_suppress_push()
  */
 function views_ui_contextual_links_suppress_pop() {
-  views_ui_contextual_links_suppress(((int) views_ui_contextual_links_suppress())-1);
+  views_ui_contextual_links_suppress(((int) views_ui_contextual_links_suppress()) - 1);
 }
 
 /**

core/modules/views_ui/views_ui.theme.inc

@@ -8,6 +8,8 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Form\FormState;
 use Drupal\Core\Render\Element;
+use Drupal\Core\Render\Element\Checkboxes;
+use Drupal\Core\Render\Element\Radios;
 use Drupal\Core\Url;
 
 /**
@@ -88,8 +90,8 @@ function template_preprocess_views_ui_build_group_filter_form(&$variables) {
 
   // Prepare default selectors.
   $form_state = new FormState();
-  $form['default_group'] = Element\Radios::processRadios($form['default_group'], $form_state, $form);
-  $form['default_group_multiple'] = Element\Checkboxes::processCheckboxes($form['default_group_multiple'], $form_state, $form);
+  $form['default_group'] = Radios::processRadios($form['default_group'], $form_state, $form);
+  $form['default_group_multiple'] = Checkboxes::processCheckboxes($form['default_group_multiple'], $form_state, $form);
   $form['default_group']['All']['#title'] = '';
 
   $rows[] = array(