Add support for using nested DTOs

docs/en/reference/dql-doctrine-query-language.rst

@@ -579,7 +579,34 @@ And then use the ``NEW`` DQL keyword :
     $query = $em->createQuery('SELECT NEW CustomerDTO(c.name, e.email, a.city, SUM(o.value)) FROM Customer c JOIN c.email e JOIN c.address a JOIN c.orders o GROUP BY c');
     $users = $query->getResult(); // array of CustomerDTO
 
-Note that you can only pass scalar expressions to the constructor.
+You can also nest several DTO : 
+
+.. code-block:: php
+
+    <?php
+    class CustomerDTO
+    {
+        public function __construct(string $name, string $email, AddressDTO $address, string|null $value = null)
+        {
+            // Bind values to the object properties.
+        }
+    }
+
+    class AddressDTO
+    {
+        public function __construct(string $street, string $city, string $zip)
+        {
+            // Bind values to the object properties.
+        }
+    }
+
+.. code-block:: php
+
+    <?php
+    $query = $em->createQuery('SELECT NEW CustomerDTO(c.name, e.email, NEW AddressDTO(a.street, a.city, a.zip)) FROM Customer c JOIN c.email e JOIN c.address a');
+    $users = $query->getResult(); // array of CustomerDTO
+
+Note that you can only pass scalar expressions or other Data Transfer Objects to the constructor.
 
 Using INDEX BY
 ~~~~~~~~~~~~~~

psalm-baseline.xml

@@ -216,6 +216,10 @@
       <code><![CDATA[return $rowData;]]></code>
       <code><![CDATA[return $rowData;]]></code>
     </ReferenceConstraintViolation>
+    <PossiblyUndefinedArrayOffset>
+      <code><![CDATA[$newObject['args']]]></code>
+      <code><![CDATA[$newObject['args']]]></code>
+    </PossiblyUndefinedArrayOffset>
   </file>
   <file src="src/Internal/Hydration/ArrayHydrator.php">
     <PossiblyInvalidArgument>
@@ -228,9 +232,6 @@
       <code><![CDATA[$result[$resultKey]]]></code>
       <code><![CDATA[$result[$resultKey]]]></code>
     </PossiblyNullArrayAssignment>
-    <PossiblyUndefinedArrayOffset>
-      <code><![CDATA[$newObject['args']]]></code>
-    </PossiblyUndefinedArrayOffset>
     <ReferenceConstraintViolation>
       <code><![CDATA[$result]]></code>
     </ReferenceConstraintViolation>
@@ -265,9 +266,6 @@
       <code><![CDATA[setValue]]></code>
       <code><![CDATA[setValue]]></code>
     </PossiblyNullReference>
-    <PossiblyUndefinedArrayOffset>
-      <code><![CDATA[$newObject['args']]]></code>
-    </PossiblyUndefinedArrayOffset>
   </file>
   <file src="src/Mapping/AssociationMapping.php">
     <LessSpecificReturnStatement>

src/Internal/Hydration/AbstractHydrator.php

@@ -252,8 +252,9 @@
      * @psalm-return array{
      *                   data: array<array-key, array>,
      *                   newObjects?: array<array-key, array{
-     *                       class: mixed,
-     *                       args?: array
+     *                       class: ReflectionClass,
+     *                       args: array,
+     *                       obj: object
      *                   }>,
      *                   scalars?: array
      *               }
@@ -281,6 +282,10 @@
                         $value = $this->buildEnum($value, $cacheKeyInfo['enumType']);
                     }
 
+                    if (! isset($rowData['newObjects'])) {
+                        $rowData['newObjects'] = [];
+                    }
+
                     $rowData['newObjects'][$objIndex]['class']           = $cacheKeyInfo['class'];
                     $rowData['newObjects'][$objIndex]['args'][$argIndex] = $value;
                     break;
@@ -335,6 +340,31 @@
             }
         }
 
+        foreach ($this->resultSetMapping()->nestedNewObjectArguments as $objIndex => ['ownerIndex' => $ownerIndex, 'argIndex' => $argIndex]) {
+            if (! isset($rowData['newObjects'][$objIndex])) {
+                continue;
+            }
+
+            $newObject = $rowData['newObjects'][$objIndex];
+            unset($rowData['newObjects'][$objIndex]);
+
+            $class = $newObject['class'];
+            $args  = $newObject['args'];
+            $obj   = $class->newInstanceArgs($args);
+
+            $rowData['newObjects'][$ownerIndex]['args'][$argIndex] = $obj;
+        }
+
+        if (isset($rowData['newObjects'])) {
+            foreach ($rowData['newObjects'] as $objIndex => $newObject) {
+                $class = $newObject['class'];
+                $args  = $newObject['args'];
+                $obj   = $class->newInstanceArgs($args);
+
+                $rowData['newObjects'][$objIndex]['obj'] = $obj;
+            }
+        }
+
         return $rowData;
     }
 

src/Internal/Hydration/ArrayHydrator.php

@@ -214,9 +214,8 @@ protected function hydrateRowData(array $row, array &$result): void
             $scalarCount = (isset($rowData['scalars']) ? count($rowData['scalars']) : 0);
 
             foreach ($rowData['newObjects'] as $objIndex => $newObject) {
-                $class = $newObject['class'];
-                $args  = $newObject['args'];
-                $obj   = $class->newInstanceArgs($args);
+                $args = $newObject['args'];
+                $obj  = $newObject['obj'];
 
                 if (count($args) === $scalarCount || ($scalarCount === 0 && count($rowData['newObjects']) === 1)) {
                     $result[$resultKey] = $obj;

src/Internal/Hydration/ObjectHydrator.php

@@ -556,9 +556,7 @@ protected function hydrateRowData(array $row, array &$result): void
             $scalarCount = (isset($rowData['scalars']) ? count($rowData['scalars']) : 0);
 
             foreach ($rowData['newObjects'] as $objIndex => $newObject) {
-                $class = $newObject['class'];
-                $args  = $newObject['args'];
-                $obj   = $class->newInstanceArgs($args);
+                $obj = $newObject['obj'];
 
                 if ($scalarCount === 0 && count($rowData['newObjects']) === 1) {
                     $result[$resultKey] = $obj;

src/Query/Parser.php

@@ -1782,6 +1782,10 @@ public function NewObjectArg(): mixed
             return $expression;
         }
 
+        if ($token->type === TokenType::T_NEW) {
+            return $this->NewObjectExpression();
+        }
+
         return $this->ScalarExpression();
     }
 

src/Query/ResultSetMapping.php

@@ -4,6 +4,7 @@
 
 namespace Doctrine\ORM\Query;
 
+use function array_merge;
 use function count;
 
 /**
@@ -152,6 +153,13 @@ class ResultSetMapping
      */
     public array $newObjectMappings = [];
 
+    /**
+     * Maps last argument for new objects in order to initiate object construction
+     *
+     * @psalm-var array<int|string, array{ownerIndex: string|int, argIndex: int|string}>
+     */
+    public array $nestedNewObjectArguments = [];
+
     /**
      * Maps metadata parameter names to the metadata attribute.
      *
@@ -544,4 +552,25 @@ public function addMetaResult(
 
         return $this;
     }
+
+    public function addNewObjectAsArgument(string|int $alias, string|int $objOwner, int $objOwnerIdx): static
+    {
+        $owner = [
+            'ownerIndex' => $objOwner,
+            'argIndex' => $objOwnerIdx,
+        ];
+
+        if (! isset($this->nestedNewObjectArguments[$owner['ownerIndex']])) {
+            $this->nestedNewObjectArguments[$alias] = $owner;
+
+            return $this;
+        }
+
+        $this->nestedNewObjectArguments = array_merge(
+            [$alias => $owner],
+            $this->nestedNewObjectArguments,
+        );
+
+        return $this;
+    }
 }

src/Query/SqlWalker.php

@@ -25,8 +25,10 @@
 use function array_keys;
 use function array_map;
 use function array_merge;
+use function array_pop;
 use function assert;
 use function count;
+use function end;
 use function implode;
 use function in_array;
 use function is_array;
@@ -85,6 +87,13 @@ class SqlWalker
      */
     private int $newObjectCounter = 0;
 
+    /**
+     * Contains nesting levels of new objects arguments
+     *
+     * @psalm-var array<int, array{0: string|int, 1: int}>
+     */
+    private array $newObjectStack = [];
+
     private readonly EntityManagerInterface $em;
     private readonly Connection $conn;
 
@@ -1482,7 +1491,14 @@ public function walkParenthesisExpression(AST\ParenthesisExpression $parenthesis
     public function walkNewObject(AST\NewObjectExpression $newObjectExpression, string|null $newObjectResultAlias = null): string
     {
         $sqlSelectExpressions = [];
-        $objIndex             = $newObjectResultAlias ?: $this->newObjectCounter++;
+        $objOwner             = $objOwnerIdx = null;
+
+        if ($this->newObjectStack !== []) {
+            [$objOwner, $objOwnerIdx] = end($this->newObjectStack);
+            $objIndex                 = $objOwner . ':' . $objOwnerIdx;
+        } else {
+            $objIndex = $newObjectResultAlias ?: $this->newObjectCounter++;
+        }
 
         foreach ($newObjectExpression->args as $argIndex => $e) {
             $resultAlias = $this->scalarResultCounter++;
@@ -1491,7 +1507,9 @@ public function walkNewObject(AST\NewObjectExpression $newObjectExpression, stri
 
             switch (true) {
                 case $e instanceof AST\NewObjectExpression:
+                    $this->newObjectStack[] = [$objIndex, $argIndex];
                     $sqlSelectExpressions[] = $e->dispatch($this);
+                    array_pop($this->newObjectStack);
                     break;
 
                 case $e instanceof AST\Subselect:
@@ -1545,6 +1563,10 @@ public function walkNewObject(AST\NewObjectExpression $newObjectExpression, stri
                 'objIndex'  => $objIndex,
                 'argIndex'  => $argIndex,
             ];
+
+            if ($objOwner !== null && $objOwnerIdx !== null) {
+                $this->rsm->addNewObjectAsArgument($objIndex, $objOwner, $objOwnerIdx);
+            }
         }
 
         return implode(', ', $sqlSelectExpressions);

tests/Tests/Models/CMS/CmsAddressDTO.php

@@ -6,7 +6,7 @@
 
 class CmsAddressDTO
 {
-    public function __construct(public string|null $country = null, public string|null $city = null, public string|null $zip = null)
+    public function __construct(public string|null $country = null, public string|null $city = null, public string|null $zip = null, public CmsAddressDTO|string|null $address = null)
     {
     }
 }

tests/Tests/Models/CMS/CmsUserDTO.php

@@ -6,7 +6,7 @@
 
 class CmsUserDTO
 {
-    public function __construct(public string|null $name = null, public string|null $email = null, public string|null $address = null, public int|null $phonenumbers = null)
+    public function __construct(public string|null $name = null, public string|null $email = null, public CmsAddressDTO|string|null $address = null, public int|null $phonenumbers = null)
     {
     }
 }

tests/Tests/Models/DDC6573/DDC6573Currency.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\DDC6573;
+
+final class DDC6573Currency
+{
+    public function __construct(private readonly string $code)
+    {
+    }
+
+    public function getCode(): string
+    {
+        return $this->code;
+    }
+}

tests/Tests/Models/DDC6573/DDC6573Item.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\DDC6573;
+
+use Doctrine\DBAL\Types\Types;
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\GeneratedValue;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\Table;
+
+#[Entity]
+#[Table(name: 'ddc6573_items')]
+class DDC6573Item
+{
+    /** @var int */
+    #[Id]
+    #[Column(type: Types::INTEGER)]
+    #[GeneratedValue(strategy: 'AUTO')]
+    public $id;
+
+    #[Column(type: Types::STRING)]
+    public string $name;
+
+    #[Column(type: Types::INTEGER)]
+    public int $priceAmount;
+
+    #[Column(type: Types::STRING, length: 3)]
+    public string $priceCurrency;
+
+    public function __construct(string $name, DDC6573Money $price)
+    {
+        $this->name          = $name;
+        $this->priceAmount   = $price->getAmount();
+        $this->priceCurrency = $price->getCurrency()->getCode();
+    }
+
+    public function getPrice(): DDC6573Money
+    {
+        return new DDC6573Money($this->priceAmount, new DDC6573Currency($this->priceCurrency));
+    }
+}

tests/Tests/Models/DDC6573/DDC6573Money.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\DDC6573;
+
+final class DDC6573Money
+{
+    public function __construct(
+        private readonly int $amount,
+        private readonly DDC6573Currency $currency,
+    ) {
+    }
+
+    public function getAmount(): int
+    {
+        return $this->amount;
+    }
+
+    public function getCurrency(): DDC6573Currency
+    {
+        return $this->currency;
+    }
+}