Issue #3048065 by Pancho: Fatal error when a file storage scheme is no longer available

src/Controller/HandlePdfController.php

@@ -4,6 +4,7 @@ namespace Drupal\fillpdf\Controller;
 
 use Drupal\Core\Url;
 use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\StreamWrapper\StreamWrapperInterface;
 use Drupal\file\Entity\File;
 use Drupal\file\FileInterface;
 use Drupal\fillpdf\Component\Helper\FillPdfMappingHelper;
@@ -17,6 +18,7 @@ use Drupal\fillpdf\TokenResolverInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\RequestStack;
+use Drupal\Core\Link;
 
 /**
  * Class HandlePdfController.
@@ -289,9 +291,30 @@ class HandlePdfController extends ControllerBase {
     }
 
     // Determine the appropriate action for the PDF.
-    $destination_path_set = !empty($fillpdf_form->destination_path->value);
-    $redirect = !empty($fillpdf_form->destination_redirect->value);
-    if ($destination_path_set) {
+    $scheme = $fillpdf_form->getStorageScheme();
+    $available_schemes = array_keys(\Drupal::service('stream_wrapper_manager')->getWrappers(StreamWrapperInterface::WRITE_VISIBLE));
+
+    // The configured file storage scheme is no longer available.
+    if (!empty($scheme) && !in_array($scheme, $available_schemes)) {
+      $id = $fillpdf_form->id();
+      // @todo: We can simpify this once an admin_title is #required,
+      // see https://www.drupal.org/project/fillpdf/issues/3040776.
+      $label = $fillpdf_form->label() . " ({$id})";
+      $this->getLogger('fillpdf')->critical('Saving a generated PDF file in unavailable storage scheme %scheme failed.', [
+        '%scheme' => "$scheme://",
+      ]);
+      if ($this->currentUser()->hasPermission('administer pdfs')) {
+        $this->messenger()->addError($this->t('File storage scheme %scheme:// is unavailable, so a PDF file generated from FillPDF form @link could not be stored.', [
+          '%scheme' => $scheme,
+          '@link' => Link::fromTextAndUrl($label, $fillpdf_form->toUrl())->toString(),
+        ]));
+      }
+      // Unset the scheme to make sure the file is only sent to the browser.
+      $scheme = NULL;
+    }
+
+    if (!empty($scheme) && !empty($fillpdf_form->getStoragePath())) {
+      $redirect = !empty($fillpdf_form->destination_redirect->value);
       $action_plugin_id = $redirect ? 'redirect' : 'save';
     }
     else {

src/Entity/FillPdfForm.php

@@ -177,6 +177,20 @@ class FillPdfForm extends ContentEntityBase implements FillPdfFormInterface {
     return $field_storage->loadMultiple($field_ids);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getStorageScheme() {
+    return $this->get('scheme')->value;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getStoragePath() {
+    return $this->get('destination_path')->value;
+  }
+
   /**
    * Allowed values callback for 'scheme' base field definition.
    *

src/FillPdfFormInterface.php

@@ -19,4 +19,22 @@ interface FillPdfFormInterface extends ContentEntityInterface {
    */
   public function getFormFields();
 
+  /**
+   * Gets this FillPdfForm's storage scheme.
+   *
+   * @return string
+   *   The storage scheme to be used for PDF files generated from this
+   *   FillPdfForm.
+   */
+  public function getStorageScheme();
+
+  /**
+   * Gets this FillPdfForm's storage path.
+   *
+   * @return string
+   *   The storage path to be used for PDF files generated from this
+   *   FillPdfForm.
+   */
+  public function getStoragePath();
+
 }

src/Plugin/FillPdfActionPlugin/FillPdfRedirectAction.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\fillpdf\Plugin\FillPdfActionPlugin;
 
+use Drupal\Core\Url;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
@@ -22,15 +23,13 @@ class FillPdfRedirectAction extends FillPdfSaveAction {
    * Saves the PDF file to the filesystem and redirects to it.
    *
    * @return \Symfony\Component\HttpFoundation\RedirectResponse
-   *   Redirects user to the generated PDF file.
+   *   Redirects user to the generated PDF file, or if saving the file fails,
+   *   to the front page.
    */
   public function execute() {
     $saved_file = $this->savePdf();
-
-    // Get file URI, then return a RedirectResponse to it.
-    $destination = $saved_file->url();
-
-    return new RedirectResponse($destination);
+    $url = ($saved_file !== FALSE) ? $saved_file->toUrl() : Url::fromRoute('<front>');
+    return new RedirectResponse($url->toString());
   }
 
 }

tests/src/Functional/HandlePdfControllerTest.php

@@ -102,4 +102,58 @@ class HandlePdfControllerTest extends FillPdfUploadTestBase {
     }
   }
 
+  /**
+   * Tests handling of an unavailable storage scheme.
+   */
+  public function testStorageSchemePrivate() {
+    $this->uploadTestPdf('fillpdf_test_v3.pdf');
+    $form_id = $this->getLatestFillPdfForm();
+    $previous_file_id = $this->getLastFileId();
+    $edit = [
+      'admin_title[0][value]' => 'Scheme test',
+      'scheme' => 'private',
+      'destination_path[0][value]' => 'test',
+    ];
+    $this->drupalPostForm(NULL, $edit, 'Save');
+
+    $fillpdf_route = Url::fromRoute('fillpdf.populate_pdf', [], [
+      'query' => [
+        'fid' => $form_id,
+      ],
+    ]);
+
+    // Hit the generation route. Make sure we are redirected to the front page.
+    $this->drupalGet($fillpdf_route);
+    $this->assertSession()->addressNotEquals('/fillpdf');
+    $this->assertSession()->statusCodeEquals(200);
+    // Get back to the front page and make sure the file was stored in the
+    // private storage.
+    $this->drupalGet('<front>');
+    $this->assertSession()->pageTextNotContains('File storage scheme private:// is unavailable');
+    $this->assertEquals(++$previous_file_id, $this->getLastFileId(), 'Generated file was stored.');
+    $this->assertStringStartsWith('private://', File::load($this->getLastFileId())->getFileUri());
+
+    // Now remove the private path from settings.php and rebuild the container.
+    $this->writeSettings([
+      'settings' => [
+        'file_private_path' => (object) [
+          'value' => '',
+          'required' => TRUE,
+        ],
+      ],
+    ]);
+    $this->rebuildContainer();
+
+    // Hit the generation route again. This time we should be redirected to the
+    // PDF file. Make sure no PHP error occured.
+    $this->drupalGet($fillpdf_route);
+    $this->assertSession()->addressEquals('/fillpdf');
+    $this->assertSession()->statusCodeEquals(200);
+    // Get back to the front page and check if an error was set, and we didn't
+    // try to store the file.
+    $this->drupalGet('<front>');
+    $this->assertSession()->pageTextContains("File storage scheme private:// is unavailable, so a PDF file generated from FillPDF form Scheme test ($form_id) could not be stored.");
+    $this->assertEquals($previous_file_id, $this->getLastFileId(), 'Generated file was not stored.');
+  }
+
 }