feature symfony#61145 [ObjectMapper] Add ObjectMapperAwareInterface to set the owning object mapper instance (soyuka)

This PR was merged into the 7.4 branch.

Discussion
----------

[ObjectMapper] Add `ObjectMapperAwareInterface` to set the owning object mapper instance

| Q             | A
| ------------- | ---
| Branch?       | 7.4
| Feature?      | yes
| Issues        | Fix symfony#61119
| License       | MIT

Because the Object Mapper calls itself and we don't offer the possibility to change the owning object mapper, its hard to change the behavior on embedded objects (you could with a transform callable but it is redundant and adds lots of complexity).
With this change the ObjectMapper can use a decorated instance and we can easily provide a way to make things like symfony#61119 work. Inside API Platform we have the same issue where we want to re-use values that have been previously mapped to existing entities, we don't want to create new classes. This is achievable with decorating the ObjectMapper but works on relations only if the called mapper inside the mapper is configurable.

Let me know how I should write the DI in the FrameworkBundle for this as it'd be nice if it worked with decoration pattern without user interactions.

Commits
-------

d6ff8d1 [ObjectMapper] allow owning ObjectMapper object

Author: nicolas-grekas

src/Symfony/Component/ObjectMapper/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+7.4
+---
+
+ * Add `ObjectMapperAwareInterface` to set the owning object mapper instance
+
 7.3
 ---
 

src/Symfony/Component/ObjectMapper/ObjectMapper.php

@@ -28,7 +28,7 @@
  *
  * @author Antoine Bluchet <[email protected]>
  */
-final class ObjectMapper implements ObjectMapperInterface
+final class ObjectMapper implements ObjectMapperInterface, ObjectMapperAwareInterface
 {
     /**
      * Tracks recursive references.
@@ -40,6 +40,7 @@ public function __construct(
         private readonly ?PropertyAccessorInterface $propertyAccessor = null,
         private readonly ?ContainerInterface $transformCallableLocator = null,
         private readonly ?ContainerInterface $conditionCallableLocator = null,
+        private ?ObjectMapperInterface $objectMapper = null,
     ) {
     }
 
@@ -211,7 +212,7 @@ private function getSourceValue(object $source, object $target, mixed $value, \S
             } elseif ($objectMap->contains($value)) {
                 $value = $objectMap[$value];
             } else {
-                $value = $this->map($value, $mapTo->target);
+                $value = ($this->objectMapper ?? $this)->map($value, $mapTo->target);
             }
         }
 
@@ -327,4 +328,12 @@ private function getSourceReflectionClass(object $source, \ReflectionClass $targ
 
         return $targetRefl;
     }
+
+    public function withObjectMapper(ObjectMapperInterface $objectMapper): static
+    {
+        $clone = clone $this;
+        $clone->objectMapper = $objectMapper;
+
+        return $clone;
+    }
 }

src/Symfony/Component/ObjectMapper/ObjectMapperAwareInterface.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\ObjectMapper;
+
+/**
+ * @experimental
+ *
+ * @author Antoine Bluchet <[email protected]>
+ */
+interface ObjectMapperAwareInterface
+{
+    /**
+     * Sets the owning ObjectMapper object.
+     */
+    public function withObjectMapper(ObjectMapperInterface $objectMapper): static;
+}

src/Symfony/Component/ObjectMapper/Tests/ObjectMapperTest.php

@@ -368,4 +368,46 @@ public static function objectMapperProvider(): iterable
         yield [new ObjectMapper()];
         yield [new ObjectMapper(new ReflectionObjectMapperMetadataFactory(), PropertyAccess::createPropertyAccessor())];
     }
+
+    public function testDecorateObjectMapper()
+    {
+        $mapper = new ObjectMapper();
+        $myMapper = new class($mapper) implements ObjectMapperInterface {
+            private ?\SplObjectStorage $embededMap = null;
+
+            public function __construct(private readonly ObjectMapperInterface $mapper)
+            {
+                $this->embededMap = new \SplObjectStorage();
+            }
+
+            public function map(object $source, object|string|null $target = null): object
+            {
+                if (isset($this->embededMap[$source])) {
+                    $target = $this->embededMap[$source];
+                }
+
+                $mapped = $this->mapper->map($source, $target);
+                $this->embededMap[$source] = $mapped;
+
+                return $mapped;
+            }
+        };
+
+        $mapper = $mapper->withObjectMapper($myMapper);
+
+        $d = new D(baz: 'foo', bat: 'bar');
+        $c = new C(foo: 'foo', bar: 'bar');
+        $myNewD = $myMapper->map($c);
+
+        $a = new A();
+        $a->foo = 'test';
+        $a->transform = 'test';
+        $a->baz = 'me';
+        $a->notinb = 'test';
+        $a->relation = $c;
+        $a->relationNotMapped = $d;
+
+        $b = $mapper->map($a);
+        $this->assertSame($myNewD, $b->relation);
+    }
 }