Fix #16334: Serializer support \JsonSerializable

framework/CHANGELOG.md

@@ -4,6 +4,7 @@ Yii Framework 2 Change Log
 2.0.33 under development
 ------------------------
 
+- Bug #16334: Serializer support `\JsonSerializable` (germanow)
 - Bug #17798: Avoid creating folder for stream log targets in `FileTarget` (wapmorgan)
 - Bug #17850: Update to `ReplaceArrayValue` config exception message (alex-code)
 - Bug #17843: Fix `yii\web\Session::setCookieParamsInternal` check param "samesite" (schevgeny)

framework/rest/Serializer.php

@@ -137,7 +137,7 @@ class Serializer extends Component
      * Serializes the given data into a format that can be easily turned into other formats.
      * This method mainly converts the objects of recognized types into array representation.
      * It will not do conversion for unknown object types or non-object data.
-     * The default implementation will handle [[Model]] and [[DataProviderInterface]].
+     * The default implementation will handle [[Model]], [[DataProviderInterface]] and [\JsonSerializable](https://www.php.net/manual/ru/class.jsonserializable.php).
      * You may override this method to support more object types.
      * @param mixed $data the data to be serialized.
      * @return mixed the converted data.
@@ -146,6 +146,8 @@ class Serializer extends Component
     {
         if ($data instanceof Model && $data->hasErrors()) {
             return $this->serializeModelErrors($data);
+        } elseif ($data instanceof \JsonSerializable) {
+            return $data->jsonSerialize();
         } elseif ($data instanceof Arrayable) {
             return $this->serializeModel($data);
         } elseif ($data instanceof DataProviderInterface) {