Setup basic layout classes for block editor

[MAILPOET-2450]

lib/Config/Menu.php

@@ -23,6 +23,7 @@ use MailPoet\AdminPages\Pages\Update;
 use MailPoet\AdminPages\Pages\WelcomeWizard;
 use MailPoet\AdminPages\Pages\WooCommerceListImport;
 use MailPoet\DI\ContainerWrapper;
+use MailPoet\Features\FeaturesController;
 use MailPoet\Util\License\Features\Subscribers as SubscribersFeature;
 use MailPoet\Util\License\License;
 use MailPoet\WP\Functions as WPFunctions;
@@ -45,17 +46,22 @@ class Menu {
   /** @var ContainerWrapper */
   private $container;
 
+  /** @var FeaturesController */
+  private $features_controller;
+
   private $subscribers_over_limit;
 
   function __construct(
     AccessControl $access_control,
     WPFunctions $wp,
     ServicesChecker $services_checker,
+    FeaturesController $features_controller,
     ContainerWrapper $container
   ) {
     $this->access_control = $access_control;
     $this->wp = $wp;
     $this->services_checker = $services_checker;
+    $this->features_controller = $features_controller;
     $this->container = $container;
   }
 
@@ -178,7 +184,7 @@ class Menu {
     });
 
     // form editor
-    $this->wp->addSubmenuPage(
+    $form_editor_page = $this->wp->addSubmenuPage(
       true,
       $this->setPageTitle(__('Form Editor', 'mailpoet')),
       $this->wp->__('Form Editor', 'mailpoet'),
@@ -190,6 +196,15 @@ class Menu {
       ]
     );
 
+    // add body class for form editor page
+    if ($this->features_controller->isSupported(FeaturesController::NEW_FORM_EDITOR)) {
+      $this->wp->addAction('load-' . $form_editor_page, function() {
+        $this->wp->addAction('admin_body_class', function ($classes) {
+          return ltrim($classes . ' block-editor-page');
+        });
+      });
+    }
+
     // Subscribers page
     $subscribers_page = $this->wp->addSubmenuPage(
       self::MAIN_PAGE_SLUG,

tests/integration/Config/MenuTest.php

@@ -7,7 +7,10 @@ use MailPoet\Config\AccessControl;
 use MailPoet\Config\Menu;
 use MailPoet\Config\ServicesChecker;
 use MailPoet\DI\ContainerWrapper;
+use MailPoet\Features\FeatureFlagsRepository;
+use MailPoet\Features\FeaturesController;
 use MailPoet\WP\Functions as WPFunctions;
+use MailPoetVendor\Doctrine\ORM\EntityManager;
 
 class MenuTest extends \MailPoetTest {
   function testItReturnsTrueIfCurrentPageBelongsToMailpoet() {
@@ -87,6 +90,7 @@ class MenuTest extends \MailPoetTest {
       new AccessControl(),
       $wp,
       new ServicesChecker,
+      new FeaturesController(new FeatureFlagsRepository(ContainerWrapper::getInstance()->get(EntityManager::class))),
       ContainerWrapper::getInstance()
     );
   }

views/form/editor.html

@@ -1,6 +1,8 @@
 <% extends 'layout.html' %>
-<% block content %>
-<div id="mailpoet_form_edit">
+<% block container %>
+<div class="block-editor">
+    <div id="mailpoet_form_edit" class="block-editor__container">
+    </div>
 </div>
 
 <script>

views/layout.html

@@ -22,6 +22,7 @@ jQuery('.toplevel_page_mailpoet-newsletters.menu-top-last')
 <% block templates %><% endblock %>
 
 <!-- main container -->
+<% block container %>
 <div class="wrap">
   <!-- notices -->
   <div id="mailpoet_notice_error" class="mailpoet_notice" style="display:none;"></div>
@@ -34,6 +35,7 @@ jQuery('.toplevel_page_mailpoet-newsletters.menu-top-last')
   <!-- content block -->
   <% block content %><% endblock %>
 </div>
+<% endblock %>
 
 <!-- stylesheets -->
 <%= stylesheet(