Used Dependency Injection

Closes #3294229

src/Plugin/Field/FieldFormatter/OptionalDateFormatterBase.php

@@ -4,6 +4,7 @@ namespace Drupal\optional_date\Plugin\Field\FieldFormatter;
 
 use Drupal\Core\Datetime\DrupalDateTime;
 use Drupal\Core\Datetime\Entity\DateFormat;
+use Drupal\Core\Datetime\DateFormatterInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FormatterBase;
 use Drupal\optional_date\Element\OptionalDate;
@@ -27,6 +28,32 @@ abstract class OptionalDateFormatterBase extends FormatterBase {
    */
   const ISO_DATETIME_FORMAT = "Y-m-d\TH:i:s\Z";
 
+  /**
+   * The date formatter service.
+   *
+   * @var \Drupal\Core\Datetime\DateFormatterInterface
+   */
+  protected $dateFormatter;
+
+  /**
+   * Constructs a OptionalDateFormatterBase object.
+   *
+   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
+   *   The date formatter service.
+   */
+  public function __construct(DateFormatterInterface $date_formatter) {
+    $this->dateFormatter = $date_formatter;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('date.formatter'),
+    );
+  }
+
   /**
    * @param $timeIsEmpty bool
    * @param $timestamp int
@@ -71,7 +98,7 @@ abstract class OptionalDateFormatterBase extends FormatterBase {
    */
   protected function getFormats() {
     $dateTime = new DrupalDateTime();
-    $formats = DateFormat::loadMultiple();
+    $formats = $this->dateFormatter->loadMultiple();
     $options = [];
 
     foreach ($formats as $id => $format) {