Issue #3337102 by Chester_, Panchuk, boddy: Configurations off-canvas: route and form

paragraphs_gridstack.permissions.yml

 administer paragraphs gridstack:
   title: "Administer Gridstack Optionsets settings"
+
+administer paragraphs gridstack styles:
+  title: "Administer Gridstack Optionsets styles settings"

paragraphs_gridstack.routing.yml

@@ -36,3 +36,12 @@ entity.paragraphs_gridstack.delete_form:
     _entity_form: paragraphs_gridstack.delete
   requirements:
     _entity_access: paragraphs_gridstack.delete
+
+# This is the router item for manage styles of the GridStack Items.
+entity.paragraphs_gridstack.manage_styles:
+  path: "/admin/paragraphs-gridstack/manage/{paragraphs_gridstack}/style-off-canvas"
+  defaults:
+    _title: "Get css styles for Gridstack Optionset"
+    _entity_form: paragraphs_gridstack.manage_styles
+  requirements:
+    _permission: "administer paragraphs gridstack styles"

src/Entity/ParagraphsGridstack.php

@@ -41,7 +41,8 @@ use Drupal\Core\Entity\Annotation\ConfigEntityType;
  *     "form" = {
  *       "add" = "Drupal\paragraphs_gridstack\Form\ParagraphsGridstackAddForm",
  *       "edit" = "Drupal\paragraphs_gridstack\Form\ParagraphsGridstackEditForm",
- *       "delete" = "Drupal\paragraphs_gridstack\Form\ParagraphsGridstackDeleteForm"
+ *       "delete" = "Drupal\paragraphs_gridstack\Form\ParagraphsGridstackDeleteForm",
+ *       "manage_styles" = "Drupal\paragraphs_gridstack\Form\ParagraphsGridstackManageStyles"
  *     }
  *   },
  *   config_prefix = "optionset",

src/Form/ParagraphsGridstackManageStyles.php

+<?php
+
+namespace Drupal\paragraphs_gridstack\Form;
+
+use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\paragraphs_gridstack\GridstackBreakpointsManagerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Class ParagraphsGridstackEditForm.
+ *
+ * Provides the edit form for our ParagraphsGridstack optionset entity.
+ */
+class ParagraphsGridstackManageStyles extends EntityForm {
+
+  /**
+   * An entity query factory for the ParagraphsGridstack entity type.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected EntityStorageInterface $entityStorage;
+
+  /**
+   * Gridstack Manager for the breakpoints.
+   *
+   * @var \Drupal\paragraphs_gridstack\GridstackBreakpointsManagerInterface
+   */
+  protected GridstackBreakpointsManagerInterface $gridstackBreakpointsManager;
+
+  /**
+   * Construct the ParagraphsGridstackFormBase.
+   *
+   * For simple entity forms, there's no need for a constructor. Our form
+   * base, however, requires an entity query factory to be injected into it
+   * from the container. We later use this query factory to build an entity
+   * query for the exists() method.
+   *
+   * @param \Drupal\Core\Entity\EntityStorageInterface $entity_storage
+   *   An entity query factory for the ParagraphsGridstack entity type.
+   */
+  public function __construct(EntityStorageInterface $entity_storage, GridstackBreakpointsManagerInterface $gridstack_breakpoints_manager) {
+    $this->entityStorage = $entity_storage;
+    $this->gridstackBreakpointsManager = $gridstack_breakpoints_manager;
+  }
+
+  /**
+   * Factory method for ParagraphsGridstackFormBase.
+   *
+   * When Drupal builds this class it does not call the constructor directly.
+   * Instead, it relies on this method to build the new object. Why? The class
+   * constructor may take multiple arguments that are unknown to Drupal. The
+   * create() method always takes one parameter -- the container. The purpose
+   * of the create() method is twofold: It provides a standard way for Drupal
+   * to construct the object, meanwhile it provides you a place to get needed
+   * constructor parameters from the container.
+   *
+   * In this case, we ask the container for an entity query factory. We then
+   * pass the factory to our class as a constructor parameter.
+   */
+  public static function create(ContainerInterface $container) {
+    $form = new static(
+      $container->get('entity_type.manager')->getStorage('paragraphs_gridstack'),
+      $container->get('paragraphs_gridstack.breakpoints_manager'),
+    );
+    $form->setMessenger($container->get('messenger'));
+    return $form;
+  }
+
+  /**
+   * Overrides Drupal\Core\Entity\EntityFormController::form().
+   *
+   * Builds the entity manage styles form.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   An associative array containing the current state of the form.
+   *
+   * @return array
+   *   An associative array containing the ParagraphsGridstack manage styles form.
+   */
+  function buildForm(array $form, FormStateInterface $form_state) {
+
+    // Build the form.
+    $form['classes'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Css classes'),
+      '#maxlength' => 255,
+      '#size' => 100,
+      '#description' => $this->t('Place your css class, if you need multiple styles use: (.d-flex .flex-column)'),
+    ];
+
+    //@todo Create correct #options.
+
+    $options= [];
+    $form['options'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Choose style options'),
+      '#options' => $options,
+      '#description' => $this->t('What options you choose?'),
+    ];
+
+    // Return the form.
+    return $form;
+  }
+
+}