Move CSV export action logic to a confirmation form.

modules/core/export/modules/csv/farm_export_csv.module

@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * @file
+ * The farmOS Export CSV module.
+ */
+
+use Drupal\farm_export_csv\Form\EntityCsvActionForm;
+use Drupal\farm_export_csv\Routing\EntityCsvActionRouteProvider;
+
+/**
+ * Implements hook_entity_type_build().
+ */
+function farm_export_csv_entity_type_build(array &$entity_types) {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+
+  // Enable the entity CSV export action on assets and logs.
+  foreach (['asset', 'log'] as $entity_type) {
+    if (!empty($entity_types[$entity_type])) {
+      $route_providers = $entity_types[$entity_type]->getRouteProviderClasses();
+      $route_providers['csv'] = EntityCsvActionRouteProvider::class;
+      $entity_types[$entity_type]->setHandlerClass('route_provider', $route_providers);
+      $entity_types[$entity_type]->setLinkTemplate('csv-action-form', '/' . $entity_type . '/csv');
+      $entity_types[$entity_type]->setFormClass('csv-action-form', EntityCsvActionForm::class);
+    }
+  }
+}

modules/core/export/modules/csv/src/Form/EntityCsvActionForm.php

@@ -0,0 +1,276 @@
+<?php
+
+namespace Drupal\farm_export_csv\Form;
+
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\File\FileSystemInterface;
+use Drupal\Core\File\FileUrlGeneratorInterface;
+use Drupal\Core\Form\ConfirmFormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\TempStore\PrivateTempStoreFactory;
+use Drupal\Core\Url;
+use Drupal\file\FileRepositoryInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\Serializer\SerializerInterface;
+
+/**
+ * Provides an entity CSV action form.
+ *
+ * @see \Drupal\farm_export_csv\Plugin\Action\EntityCsv
+ * @see \Drupal\Core\Entity\Form\DeleteMultipleForm
+ */
+class EntityCsvActionForm extends ConfirmFormBase {
+
+  /**
+   * The tempstore factory.
+   *
+   * @var \Drupal\Core\TempStore\SharedTempStore
+   */
+  protected $tempStore;
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The serializer service.
+   *
+   * @var \Symfony\Component\Serializer\SerializerInterface
+   */
+  protected $serializer;
+
+  /**
+   * The file system service.
+   *
+   * @var \Drupal\Core\File\FileSystemInterface
+   */
+  protected $fileSystem;
+
+  /**
+   * The default file scheme.
+   *
+   * @var string
+   */
+  protected $defaultFileScheme;
+
+  /**
+   * The file repository service.
+   *
+   * @var \Drupal\file\FileRepositoryInterface
+   */
+  protected $fileRepository;
+
+  /**
+   * The file URL generator.
+   *
+   * @var \Drupal\Core\File\FileUrlGeneratorInterface
+   */
+  protected $fileUrlGenerator;
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $user;
+
+  /**
+   * The entity type.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeInterface
+   */
+  protected $entityType;
+
+  /**
+   * The entities to export.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface[]
+   */
+  protected $entities;
+
+  /**
+   * Constructs an EntityCsvActionForm form object.
+   *
+   * @param \Drupal\Core\TempStore\PrivateTempStoreFactory $temp_store_factory
+   *   The tempstore factory.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   * @param \Symfony\Component\Serializer\SerializerInterface $serializer
+   *   The serializer service.
+   * @param \Drupal\Core\File\FileSystemInterface $file_system
+   *   The file system service.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The config factory service.
+   * @param \Drupal\file\FileRepositoryInterface $file_repository
+   *   The file repository service.
+   * @param \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator
+   *   The file URL generator.
+   * @param \Drupal\Core\Session\AccountInterface $user
+   *   The current user.
+   */
+  public function __construct(PrivateTempStoreFactory $temp_store_factory, EntityTypeManagerInterface $entity_type_manager, SerializerInterface $serializer, FileSystemInterface $file_system, ConfigFactoryInterface $config_factory, FileRepositoryInterface $file_repository, FileUrlGeneratorInterface $file_url_generator, AccountInterface $user) {
+    $this->tempStore = $temp_store_factory->get('entity_csv_confirm');
+    $this->entityTypeManager = $entity_type_manager;
+    $this->serializer = $serializer;
+    $this->fileSystem = $file_system;
+    $this->defaultFileScheme = $config_factory->get('system.file')->get('default_scheme') ?? 'public';
+    $this->fileRepository = $file_repository;
+    $this->fileUrlGenerator = $file_url_generator;
+    $this->user = $user;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('tempstore.private'),
+      $container->get('entity_type.manager'),
+      $container->get('serializer'),
+      $container->get('file_system'),
+      $container->get('config.factory'),
+      $container->get('file.repository'),
+      $container->get('file_url_generator'),
+      $container->get('current_user'),
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    // Get entity type ID from the route because ::buildForm has not yet been
+    // called.
+    $entity_type_id = $this->getRouteMatch()->getParameter('entity_type_id');
+    return $entity_type_id . '_csv_action_confirm_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getQuestion() {
+    return $this->formatPlural(count($this->entities), 'Are you sure you want to export a CSV of this @item?', 'Are you sure you want to export a CSV of these @items?', [
+      '@item' => $this->entityType->getSingularLabel(),
+      '@items' => $this->entityType->getPluralLabel(),
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCancelUrl() {
+    if ($this->entityType->hasLinkTemplate('collection')) {
+      return new Url('entity.' . $this->entityType->id() . '.collection');
+    }
+    else {
+      return new Url('<front>');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDescription() {
+    return '';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConfirmText() {
+    return $this->t('Export');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, $entity_type_id = NULL) {
+
+    // If we don't have an entity type or list of entities, redirect.
+    $this->entityType = $this->entityTypeManager->getDefinition($entity_type_id);
+    $this->entities = $this->tempStore->get($this->user->id() . ':' . $entity_type_id);
+    if (empty($entity_type_id) || empty($this->entities)) {
+      return new RedirectResponse($this->getCancelUrl()
+        ->setAbsolute()
+        ->toString());
+    }
+
+    // Delegate to the parent method.
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+
+    // Filter out entities the user doesn't have access to.
+    $inaccessible_entities = [];
+    $accessible_entities = [];
+    foreach ($this->entities as $entity) {
+      if (!$entity->access('view', $this->currentUser())) {
+        $inaccessible_entities[] = $entity;
+        continue;
+      }
+      $accessible_entities[] = $entity;
+    }
+
+    // Serialize the entities with the csv format.
+    $output = $this->serializer->serialize($accessible_entities, 'csv');
+
+    // Prepare the file directory.
+    $directory = $this->defaultFileScheme . '://csv';
+    $this->fileSystem->prepareDirectory($directory, FileSystemInterface::CREATE_DIRECTORY);
+
+    // Create the file.
+    $filename = 'csv_export-' . date('c') . '.csv';
+    $destination = "$directory/$filename";
+    try {
+      $file = $this->fileRepository->writeData($output, $destination);
+    }
+
+    // If file creation failed, bail with a warning.
+    catch (\Exception $e) {
+      $this->messenger()->addWarning($this->t('Could not create file.'));
+      return;
+    }
+
+    // Make the file temporary.
+    $file->status = 0;
+    $file->save();
+
+    // Add warning message for inaccessible entities.
+    if (!empty($inaccessible_entities)) {
+      $inaccessible_count = count($inaccessible_entities);
+      $this->messenger()->addWarning($this->formatPlural($inaccessible_count, 'Could not export @count @item because you do not have the necessary permissions.', 'Could not export @count @items because you do not have the necessary permissions.', [
+        '@item' => $this->entityType->getSingularLabel(),
+        '@items' => $this->entityType->getPluralLabel(),
+      ]));
+    }
+
+    // Add confirmation message.
+    if (count($accessible_entities)) {
+      $this->messenger()->addStatus($this->formatPlural(count($accessible_entities), 'Exported @count @item.', 'Exported @count @items', [
+        '@item' => $this->entityType->getSingularLabel(),
+        '@items' => $this->entityType->getPluralLabel(),
+      ]));
+    }
+
+    // Show a link to the file.
+    $url = $this->fileUrlGenerator->generateAbsoluteString($file->getFileUri());
+    $this->messenger()->addMessage($this->t('CSV file created: <a href=":url">%filename</a>', [
+      ':url' => $url,
+      '%filename' => $file->label(),
+    ]));
+
+    $this->tempStore->delete($this->currentUser()->id() . ':' . $this->entityType->id());
+    $form_state->setRedirectUrl($this->getCancelUrl());
+  }
+
+}

modules/core/export/modules/csv/src/Plugin/Action/Derivative/EntityCsvDeriver.php

@@ -22,6 +22,7 @@ class EntityCsvDeriver extends EntityActionDeriverBase {
         $definition = $base_plugin_definition;
         $definition['type'] = $entity_type_id;
         $definition['label'] = $this->t('Export @entity_type CSV', ['@entity_type' => $entity_type->getSingularLabel()]);
+        $definition['confirm_form_route_name'] = 'entity.' . $entity_type->id() . '.csv_form';
         $definitions[$entity_type_id] = $definition;
       }
       $this->derivatives = $definitions;

modules/core/export/modules/csv/src/Plugin/Action/EntityCsv.php

@@ -3,14 +3,10 @@
 namespace Drupal\farm_export_csv\Plugin\Action;
 
 use Drupal\Core\Action\Plugin\Action\EntityActionBase;
-use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\File\FileSystemInterface;
-use Drupal\Core\File\FileUrlGeneratorInterface;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\file\FileRepositoryInterface;
+use Drupal\Core\TempStore\PrivateTempStoreFactory;
 use Symfony\Component\DependencyInjection\ContainerInterface;
-use Symfony\Component\Serializer\SerializerInterface;
 
 /**
  * Action that exports a CSV file of entities.
@@ -24,39 +20,18 @@ use Symfony\Component\Serializer\SerializerInterface;
 class EntityCsv extends EntityActionBase {
 
   /**
-   * The serializer service.
+   * The tempstore object.
    *
-   * @var \Symfony\Component\Serializer\SerializerInterface
+   * @var \Drupal\Core\TempStore\SharedTempStore
    */
-  protected $serializer;
+  protected $tempStore;
 
   /**
-   * The file system service.
+   * The current user.
    *
-   * @var \Drupal\Core\File\FileSystemInterface
+   * @var \Drupal\Core\Session\AccountInterface
    */
-  protected $fileSystem;
-
-  /**
-   * The default file scheme.
-   *
-   * @var string
-   */
-  protected $defaultFileScheme;
-
-  /**
-   * The file repository service.
-   *
-   * @var \Drupal\file\FileRepositoryInterface
-   */
-  protected $fileRepository;
-
-  /**
-   * The file URL generator.
-   *
-   * @var \Drupal\Core\File\FileUrlGeneratorInterface
-   */
-  protected $fileUrlGenerator;
+  protected $currentUser;
 
   /**
    * Constructs a new EntityCsv object.
@@ -69,24 +44,15 @@ class EntityCsv extends EntityActionBase {
    *   The plugin implementation definition.
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager service.
-   * @param \Symfony\Component\Serializer\SerializerInterface $serializer
-   *   The serializer service.
-   * @param \Drupal\Core\File\FileSystemInterface $file_system
-   *   The file system service.
-   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
-   *   The config factory service.
-   * @param \Drupal\file\FileRepositoryInterface $file_repository
-   *   The file repository service.
-   * @param \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator
-   *   The file URL generator.
+   * @param \Drupal\Core\TempStore\PrivateTempStoreFactory $temp_store_factory
+   *   The tempstore factory.
+   * @param \Drupal\Core\Session\AccountInterface $current_user
+   *   Current user.
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, SerializerInterface $serializer, FileSystemInterface $file_system, ConfigFactoryInterface $config_factory, FileRepositoryInterface $file_repository, FileUrlGeneratorInterface $file_url_generator) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, PrivateTempStoreFactory $temp_store_factory, AccountInterface $current_user) {
     parent::__construct($configuration, $plugin_id, $plugin_definition, $entity_type_manager);
-    $this->serializer = $serializer;
-    $this->fileSystem = $file_system;
-    $this->defaultFileScheme = $config_factory->get('system.file')->get('default_scheme') ?? 'public';
-    $this->fileRepository = $file_repository;
-    $this->fileUrlGenerator = $file_url_generator;
+    $this->tempStore = $temp_store_factory->get('entity_csv_confirm');
+    $this->currentUser = $current_user;
   }
 
   /**
@@ -98,11 +64,8 @@ class EntityCsv extends EntityActionBase {
       $plugin_id,
       $plugin_definition,
       $container->get('entity_type.manager'),
-      $container->get('serializer'),
-      $container->get('file_system'),
-      $container->get('config.factory'),
-      $container->get('file.repository'),
-      $container->get('file_url_generator'),
+      $container->get('tempstore.private'),
+      $container->get('current_user'),
     );
   }
 
@@ -110,37 +73,8 @@ class EntityCsv extends EntityActionBase {
    * {@inheritdoc}
    */
   public function executeMultiple(array $entities) {
-
-    // Serialize the entities.
-    $output = $this->serializer->serialize($entities, 'csv');
-
-    // Prepare the file directory.
-    $directory = $this->defaultFileScheme . '://csv';
-    $this->fileSystem->prepareDirectory($directory, FileSystemInterface::CREATE_DIRECTORY);
-
-    // Create the file.
-    $filename = 'csv_export-' . date('c') . '.csv';
-    $destination = "$directory/$filename";
-    try {
-      $file = $this->fileRepository->writeData($output, $destination);
-    }
-
-    // If file creation failed, bail with a warning.
-    catch (\Exception $e) {
-      $this->messenger()->addWarning($this->t('Could not create file.'));
-      return;
-    }
-
-    // Make the file temporary.
-    $file->status = 0;
-    $file->save();
-
-    // Show a link to the file.
-    $url = $this->fileUrlGenerator->generateAbsoluteString($file->getFileUri());
-    $this->messenger()->addMessage($this->t('CSV file created: <a href=":url">%filename</a>', [
-      ':url' => $url,
-      '%filename' => $file->label(),
-    ]));
+    /** @var \Drupal\Core\Entity\EntityInterface[] $entities */
+    $this->tempStore->set($this->currentUser->id() . ':' . $this->getPluginDefinition()['type'], $entities);
   }
 
   /**

modules/core/export/modules/csv/src/Routing/EntityCsvActionRouteProvider.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Drupal\farm_export_csv\Routing;
+
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\Routing\EntityRouteProviderInterface;
+use Symfony\Component\Routing\Route;
+use Symfony\Component\Routing\RouteCollection;
+
+/**
+ * Provides routes for the entity CSV export action.
+ */
+class EntityCsvActionRouteProvider implements EntityRouteProviderInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRoutes(EntityTypeInterface $entity_type) {
+    $collection = new RouteCollection();
+    $entity_type_id = $entity_type->id();
+    if ($route = $this->getEntityCsvFormRoute($entity_type)) {
+      $collection->add("entity.$entity_type_id.csv_form", $route);
+    }
+
+    return $collection;
+  }
+
+  /**
+   * Gets the entity CSV export form route.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type.
+   *
+   * @return \Symfony\Component\Routing\Route|null
+   *   The generated route, if available.
+   */
+  protected function getEntityCsvFormRoute(EntityTypeInterface $entity_type) {
+    if ($entity_type->hasLinkTemplate('csv-action-form')) {
+      $route = new Route($entity_type->getLinkTemplate('csv-action-form'));
+      $route->setDefault('_form', $entity_type->getFormClass('csv-action-form'));
+      $route->setDefault('entity_type_id', $entity_type->id());
+      $route->setRequirement('_user_is_logged_in', 'TRUE');
+      return $route;
+    }
+  }
+
+}