[GH-12209] Naive prototype for loading partial objects fully

src/Internal/Hydration/ObjectHydrator.php

@@ -264,6 +264,7 @@ private function getEntity(array $data, string $dqlAlias): object
         }
 
         $this->hints['fetchAlias'] = $dqlAlias;
+        $this->hints['isPartial']  = $this->rsm->partialAliases[$dqlAlias] ?? false;
 
         return $this->uow->createEntity($className, $data, $this->hints);
     }

src/Internal/Hydration/SimpleObjectHydrator.php

@@ -39,6 +39,8 @@ protected function prepare(): void
         }
 
         $this->class = $this->getClassMetadata(reset($this->resultSetMapping()->aliasMap));
+
+        $this->hints['isPartial'] = count($this->rsm->partialAliases) > 0;
     }
 
     protected function cleanup(): void

src/Proxy/ProxyFactory.php

@@ -206,7 +206,7 @@ public function __construct(
      * @param class-string $className
      * @param array<mixed> $identifier
      */
-    public function getProxy(string $className, array $identifier): object
+    public function getProxy(string $className, array $identifier, bool $assignIdentifiers = true): object
     {
         if ($this->em->getConfiguration()->isNativeLazyObjectsEnabled()) {
             $classMetadata       = $this->em->getClassMetadata($className);
@@ -228,8 +228,10 @@ public function getProxy(string $className, array $identifier): object
                 }
             }, ReflectionClass::SKIP_INITIALIZATION_ON_SERIALIZE);
 
-            foreach ($identifier as $idField => $value) {
-                $classMetadata->propertyAccessors[$idField]->setValue($proxy, $value);
+            if ($assignIdentifiers) {
+                foreach ($identifier as $idField => $value) {
+                    $classMetadata->propertyAccessors[$idField]->setValue($proxy, $value);
+                }
             }
 
             return $proxy;

src/Query/ResultSetMapping.php

@@ -42,6 +42,13 @@ class ResultSetMapping
      */
     public array $aliasMap = [];
 
+    /**
+     * Weather this alias is for a partially loaded entity
+     *
+     * @var array<string, bool>
+     */
+    public array $partialAliases = [];
+
     /**
      * Maps alias names to related association field names.
      *
@@ -207,7 +214,7 @@ class ResultSetMapping
      *
      * @todo Rename: addRootEntity
      */
-    public function addEntityResult(string $class, string $alias, string|null $resultAlias = null): static
+    public function addEntityResult(string $class, string $alias, string|null $resultAlias = null, bool $isPartial = false): static
     {
         $this->aliasMap[$alias]       = $class;
         $this->entityMappings[$alias] = $resultAlias;
@@ -216,6 +223,10 @@ public function addEntityResult(string $class, string $alias, string|null $resul
             $this->isMixed = true;
         }
 
+        if ($isPartial) {
+            $this->partialAliases[$alias] = true;
+        }
+
         return $this;
     }
 
@@ -388,12 +399,16 @@ public function getColumnAliasByField(string $alias, string $fieldName): string
      *
      * @todo Rename: addJoinedEntity
      */
-    public function addJoinedEntityResult(string $class, string $alias, string $parentAlias, string $relation): static
+    public function addJoinedEntityResult(string $class, string $alias, string $parentAlias, string $relation, bool $isPartial = false): static
     {
         $this->aliasMap[$alias]       = $class;
         $this->parentAliasMap[$alias] = $parentAlias;
         $this->relationMap[$alias]    = $relation;
 
+        if ($isPartial) {
+            $this->partialAliases[$alias] = true;
+        }
+
         return $this;
     }
 

src/Query/SqlWalker.php

@@ -1,3 +1,3 @@
 <?php
 
 declare(strict_types=1);
@@ -112,9 +112,9 @@
     /**
      * A list of classes that appear in non-scalar SelectExpressions.
      *
-     * @phpstan-var array<string, array{class: ClassMetadata, dqlAlias: string, resultAlias: string|null}>
+     * @phpstan-var array<string, array{class: ClassMetadata, dqlAlias: string, resultAlias: string|null, partial: bool}>>
      */
     private array $selectedClasses = [];
 
     /**
      * The DQL alias of the root class of the currently traversed query.
@@ -679,10 +679,11 @@
             $class       = $selectedClass['class'];
             $dqlAlias    = $selectedClass['dqlAlias'];
             $resultAlias = $selectedClass['resultAlias'];
+            $isPartial   = $selectedClass['partial'];
 
             // Register as entity or joined entity result
             if (! isset($this->queryComponents[$dqlAlias]['relation'])) {
-                $this->rsm->addEntityResult($class->name, $dqlAlias, $resultAlias);
+                $this->rsm->addEntityResult($class->name, $dqlAlias, $resultAlias, $isPartial);
             } else {
                 assert(isset($this->queryComponents[$dqlAlias]['parent']));
 
@@ -691,6 +692,7 @@
                     $dqlAlias,
                     $this->queryComponents[$dqlAlias]['parent'],
                     $this->queryComponents[$dqlAlias]['relation']->fieldName,
+                    $isPartial,
                 );
             }
 
@@ -760,7 +762,7 @@
                     if ($assoc->isToOneOwningSide()) {
                         $targetClass = $this->em->getClassMetadata($assoc->targetEntity);
 
                         foreach ($assoc->joinColumns as $joinColumn) {
                             $columnName  = $joinColumn->name;
                             $columnAlias = $this->getSQLColumnAlias($columnName);
                             $columnType  = PersisterHelper::getTypeOfColumn($joinColumn->referencedColumnName, $targetClass, $this->em);
@@ -1386,6 +1388,7 @@
                 'class'       => $class,
                 'dqlAlias'    => $dqlAlias,
                 'resultAlias' => $resultAlias,
+                'partial'     => $partialFieldSet !== [],
             ];
         }
 

src/UnitOfWork.php

@@ -2395,19 +2395,22 @@ public function createEntity(string $className, array $data, array &$hints = [])
 
                     Hydrator::hydrate($entity, (array) $class->reflClass->newInstanceWithoutConstructor());
                 }
-            } else {
-                if (
+            } elseif (
                     ! isset($hints[Query::HINT_REFRESH])
                     || (isset($hints[Query::HINT_REFRESH_ENTITY]) && $hints[Query::HINT_REFRESH_ENTITY] !== $entity)
-                ) {
-                    return $entity;
-                }
+            ) {
+                return $entity;
             }
 
             $this->originalEntityData[$oid] = $data;
         } else {
-            $entity = $class->newInstance();
-            $oid    = spl_object_id($entity);
+            if ($this->em->getConfiguration()->isNativeLazyObjectsEnabled() && isset($hints['isPartial']) && $hints['isPartial']) {
+                $entity = $this->em->getProxyFactory()->getProxy($class->name, $id, false);
+            } else {
+                $entity = $class->newInstance();
+            }
+
+            $oid = spl_object_id($entity);
             $this->registerManaged($entity, $id, $data);
 
             if (isset($hints[Query::HINT_READ_ONLY]) && $hints[Query::HINT_READ_ONLY] === true) {

tests/Tests/ORM/Functional/QueryTest.php

@@ -109,6 +109,55 @@
         self::assertEquals('Symfony 2', $users[0]->articles[1]->topic);
     }
 
+    public function testJoinPartialObjectHydration(): void
+    {
+        if (!$this->_em->getConfiguration()->isNativeLazyObjectsEnabled()) {
+            $this->markTestSkipped('Test requires native lazy objects to be enabled.');
+        }
+
+        $user           = new CmsUser();
+        $user->name     = 'Guilherme';
+        $user->username = 'gblanco';
+        $user->status   = 'developer';
+
+        $article1        = new CmsArticle();
+        $article1->topic = 'Doctrine 2';
+        $article1->text  = 'This is an introduction to Doctrine 2.';
+        $user->addArticle($article1);
+
+        $article2        = new CmsArticle();
+        $article2->topic = 'Symfony 2';
+        $article2->text  = 'This is an introduction to Symfony 2.';
+        $user->addArticle($article2);
+
+        $this->_em->persist($user);
+        $this->_em->persist($article1);
+        $this->_em->persist($article2);
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $query = $this->_em->createQuery('select partial u.{id, username}, partial a.{id, topic} from ' . CmsUser::class . ' u join u.articles a ORDER BY a.topic');
+        $users = $query->getResult();
+
+        $queries          = count($this->getQueryLog()->queries);
+        $topicsByUsername = [];
+        foreach ($users as $user) {
+            $topicsByUsername[$user->username] = $user->articles->map(static fn ($article) => $article->topic)->toArray();
+        }
+
+        self::assertQueryCount($queries);
+        self::assertEquals(['gblanco' => ['Doctrine 2', 'Symfony 2']], $topicsByUsername);
+
+        $userNames = [];
+        foreach ($users as $user) {
+            $userNames[] = $user->name;
+        }
+
+        self::assertQueryCount($queries + 1);
+        self::assertEquals(['Guilherme'], $userNames);
+    }
+
     public function testJoinPartialArrayHydration(): void
     {
         $user           = new CmsUser();

tests/Tests/ORM/Functional/ValueObjectsTest.php

@@ -182,6 +182,10 @@
 
     public function testPartialDqlOnEmbeddedObjectsField(): void
     {
+        if (!$this->_em->getConfiguration()->isNativeLazyObjectsEnabled()) {
+            $this->markTestSkipped('Test requires native lazy objects to be enabled.');
+        }
+
         $person = new DDC93Person('Karl', new DDC93Address('Foo', '12345', 'Gosport', new DDC93Country('England')));
         $this->_em->persist($person);
         $this->_em->flush();
@@ -226,9 +230,11 @@
 
         // Selected field must be equal, all other fields must be null.
         self::assertEquals('Gosport', $person->address->city);
+        // TODO: What about lazy loading embeddables? *shrug*
         self::assertNull($person->address->street);
         self::assertNull($person->address->zip);
         self::assertNull($person->address->country);
+        // this actually loads the name field lazily
         self::assertNull($person->name);
     }
 

tests/Tests/ORM/Hydration/ObjectHydratorTest.php

@@ -1029,12 +1029,12 @@ public function testCreatesProxyForLazyLoadingWithForeignKeys(): void
             'Proxies',
             ProxyFactory::AUTOGENERATE_ALWAYS,
         ) extends ProxyFactory {
-            public function getProxy(string $className, array $identifier): object
+            public function getProxy(string $className, array $identifier, bool $assignIdentifiers = false): object
             {
                 TestCase::assertSame(ECommerceShipping::class, $className);
                 TestCase::assertSame(['id' => 42], $identifier);
 
-                return parent::getProxy($className, $identifier);
+                return parent::getProxy($className, $identifier, $assignIdentifiers);
             }
         };
 
@@ -1083,12 +1083,12 @@ public function testCreatesProxyForLazyLoadingWithForeignKeysWithAliasedProductE
             'Proxies',
             ProxyFactory::AUTOGENERATE_ALWAYS,
         ) extends ProxyFactory {
-            public function getProxy(string $className, array $identifier): object
+            public function getProxy(string $className, array $identifier, bool $assignIdentifiers = false): object
             {
                 TestCase::assertSame(ECommerceShipping::class, $className);
                 TestCase::assertSame(['id' => 42], $identifier);
 
-                return parent::getProxy($className, $identifier);
+                return parent::getProxy($className, $identifier, $assignIdentifiers);
             }
         };