Deserialization fails when discriminator base class extends another class

[gregory90]

This code:

abstract class Thing {}

/**
* @Serializer\Discriminator(field = "type", map = {
*    "car": "Car",
*    "moped": "Moped",
* })
**/
abstract class Vehicle extends Thing
{
    /** @Serializer\Type("integer") */
    public $km;

    public function __construct($km)
    {
            $this->km = (integer) $km;
    }
}

class Moped extends Vehicle
{
}

class Car extends Vehicle
{
}

$jsonData = '{"km":5,"type":"car"}';
$serializer = JMS\Serializer\SerializerBuilder::create()->build();

$object = $serializer->deserialize($jsonData, 'Vehicle', 'json');

Fails with:

PHP Fatal error: Cannot instantiate abstract class Vehicle in .../jms/serializer/src/JMS/Serializer/Construction/UnserializeObjectConstructor.php on line 28

Am I missing something?

[jaymecd]

Same here, after small research I noticed that base class (in this case Vehicle) looses discriminatorMap and other related metadata, while it extends other class.

According to the doc its not allowed to define @Discriminator on derived class, only on top class in chain, what makes life sometimes harder.

This is var_dump($metadata) output without extend:

class JMS\Serializer\Metadata\ClassMetadata 
{
    ...
    public $discriminatorDisabled => bool(false)
    public $discriminatorBaseClass => string(7) "Vehicle"
    public $discriminatorFieldName => string(4) "type"
    public $discriminatorValue => string(4) "car"
    public $discriminatorMap => array(2) {
        'car' =>  string(3) "Car",
        'moped' =>  string(5) "Moped"
    }
    ...
}

This is var_dump($metadata) output with extend:

class JMS\Serializer\Metadata\ClassMetadata 
{
    ...
    public $discriminatorDisabled => bool(false)
    public $discriminatorBaseClass => NULL
    public $discriminatorFieldName => NULL 
    public $discriminatorValue => NULL
    public $discriminatorMap => array(0) {}
    ...
}

[mnapoli]

Same here (btw not related to #56), that's a problem if you have a base entity class.

[goetas]

solved by #382

[coyl]

Still reproducing:

class Foo{}
/**
 * @Serializer\Discriminator(field = "type", map = {"car": "Car", "moped": "Moped"})
 */
abstract class Vehicle extends Foo { }
class Car extends Vehicle { }
class Moped extends Vehicle { }
....
$job = new Moped();
/** @var SerializerInterface $ser */
$data = $ser->serialize($job, 'json');

echo $data;
$job = $ser->deserialize($data, Vehicle::class, 'json');

output

{
    "type": "moped"
}

  [Doctrine\Instantiator\Exception\InvalidArgumentException]                                        
  The provided class "Vehicle" is abstract, and can not be instantiated