Issue #3217949 - Drupal 9 Support

Drupal 9 compatibility Closes #3217949

src/Form/OptionsForm.php

@@ -7,13 +7,41 @@
 
 namespace Drupal\easychart\Form;
 
+use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\Form\FormBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
 
 class OptionsForm extends FormBase {
 
+  /**
+   * The file system service.
+   *
+   * @var \Drupal\Core\File\FileSystemInterface
+   */
+  protected $fileSystem;
+
+  /**
+   * OptionsForm constructor.
+   *
+   * @param \Drupal\Core\File\FileSystemInterface $file_system
+   *   The file handler.
+   */
+  public function __construct(FileSystemInterface $file_system = NULL) {
+    $this->fileSystem = $file_system;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('file_system')
+    );
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -94,11 +122,11 @@ class OptionsForm extends FormBase {
       }
 
       // Write to file.
-      file_unmanaged_save_data(json_encode($current_options), 'public://easychart-options.json', FILE_EXISTS_REPLACE);
-      drupal_set_message($this->t('The configuration options have been saved.'));
+      $this->fileSystem->saveData(json_encode($current_options), 'public://easychart-options.json', FileSystemInterface::EXISTS_REPLACE);
+      $this->messenger()->addMessage($this->t('The configuration options have been saved.'));
     }
     else {
-      drupal_set_message($this->t('Something went wrong saving the options.'));
+      $this->messenger()->addMessage($this->t('Something went wrong saving the options.'));
     }
   }