Symfony 4 custom deserializer returns empty properties in entity

I have a custom Symfony 4 deserializer

class CardImageDecoder implements EncoderInterface, DecoderInterface
{
    public function encode($data, $format, array $context = [])
    {
        if($format !== 'json') {
            throw new EncodingFormatNotSupportedException(sprintf('Format %s is not supported by encoder %s', $format, __CLASS__));
        }

        $result = json_encode($data);

        if(json_last_error() !== JSON_ERROR_NONE) {
            // don't bother with a custom error message
            throw new Exception(sprintf('Unable to encode data, got error message: %s', json_last_error_msg()));
        }

        return $result;
    }

    public function supportsEncoding($format)
    {
        return 'json' === $format;
    }

    public function decode($data, $format, array $context = [])
    {
        if($format !== 'array') {
            throw new DecodingFormatNotSupportedException(sprintf('Format %s is not supported by encoder %s', $format, __CLASS__));
        }

        if(!is_array($data)) {
            throw new UnexpectedValueException(sprintf('Expected array got %s', gettype($data)));
        }

        $cardInstance = new CardImages();
        $cardInstance->setHeight($data['h'] ?? 0);
        $cardInstance->setPath($data['url'] ?? '');
        $cardInstance->setWidth($data['w'] ?? 0);

        return $cardInstance;
    }

    public function supportsDecoding($format)
    {
        return 'array' === $format;
    }
}

The way I’m deserializing is pretty straight forward:

$json = '
{
"url": "some url",
"h": 1004,
"w": 768
}';

$encoders = [new CardImageDecoder()];
$normalizers = [new ObjectNormalizer()];
$serializer = new Serializer($normalizers, $encoders);

$cardImage = $serializer->deserialize(json_decode($json, true), CardImages::class, 'array');

/** @var $cardImage CardImages */
var_dump($cardImage);

However, I get this result returned:

object(AppEntityCardImages)#158 (5) {
  ["id":"AppEntityCardImages":private]=>
  NULL
  ["path":"AppEntityCardImages":private]=>
  NULL
  ["height":"AppEntityCardImages":private]=>
  NULL
  ["width":"AppEntityCardImages":private]=>
  NULL
  ["movie":"AppEntityCardImages":private]=>
  NULL
}

Now, if I were to do a dump, just before the return in the decode part of the decoder, I’d get this:

...
$cardInstance->setWidth($data['w'] ?? 0);

var_dump($cardInstance);

object(AppEntityCardImages)#153 (5) {
  ["id":"AppEntityCardImages":private]=>
  NULL
  ["path":"AppEntityCardImages":private]=>
  string(8) "some url"
  ["height":"AppEntityCardImages":private]=>
  int(1004)
  ["width":"AppEntityCardImages":private]=>
  int(768)
  ["movie":"AppEntityCardImages":private]=>
  NULL
}

Ignoring the not set properties(which I’m fine with), it should work quite nicely, but it doesn’t.

For the life of me I can’t figure out what’s wrong.

Any help is appreciated.

Answer

You are thinking way to complicated.

Tested, working example:
Your entity – take a closer look at the end – we need setters with the names of your array keys:

namespace AppDomain;


class CardImages
{
    /** @var int|null */
    private $id;
    /** @var int|null */
    private $height;
    /** @var string|null */
    private $path;
    /** @var int|null */
    private $width;
    /** @var mixed */
    private $movie;

    /**
     * @return int|null
     */
    public function getId(): ?int
    {
        return $this->id;
    }

    /**
     * @param int|null $id
     * @return CardImages
     */
    public function setId(?int $id): CardImages
    {
        $this->id = $id;
        return $this;
    }

    /**
     * @return int|null
     */
    public function getHeight(): ?int
    {
        return $this->height;
    }

    /**
     * @param int|null $height
     * @return CardImages
     */
    public function setHeight(?int $height): CardImages
    {
        $this->height = $height;
        return $this;
    }

    /**
     * @return string|null
     */
    public function getPath(): ?string
    {
        return $this->path;
    }

    /**
     * @param string|null $path
     * @return CardImages
     */
    public function setPath(?string $path): CardImages
    {
        $this->path = $path;
        return $this;
    }

    /**
     * @return int|null
     */
    public function getWidth(): ?int
    {
        return $this->width;
    }

    /**
     * @param int|null $width
     * @return CardImages
     */
    public function setWidth(?int $width): CardImages
    {
        $this->width = $width;
        return $this;
    }

    /**
     * @return mixed
     */
    public function getMovie()
    {
        return $this->movie;
    }

    /**
     * @param mixed $movie
     * @return CardImages
     */
    public function setMovie($movie)
    {
        $this->movie = $movie;
        return $this;
    }

    public function setH(?int $height): CardImages
    {
        $this->setHeight($height);

        return $this;
    }

    public function setUrl(?string $url): CardImages
    {
        $this->setPath($url);
        return $this;
    }

    public function setW(?int $width): CardImages
    {
        $this->setWidth($width);

        return $this;
    }
}

Simple Controller to test the Output:

<?php       
namespace AppInfrastructureWebController;

use AppDomainCardImages;
use SymfonyBundleFrameworkBundleControllerAbstractController;
use SymfonyComponentHttpFoundationResponse;
use SymfonyComponentRoutingAnnotationRoute;
use SymfonyComponentSerializerNormalizerObjectNormalizer;
use SymfonyComponentSerializerSerializerInterface;

/**
 * Class IndexController.
 *
 * @Route("/test")
 */
class TestController extends AbstractController
{
    private $serializer;

    public function __construct(SerializerInterface $serializer)
    {
        $this->serializer = $serializer;
    }

    /**
     * @Route("")
     *
     * @return Response
     */
    public function indexAction(): Response
    {
        $data = [
            [
                'h' => 100,
                'w' => 100,
                'path' => '/asdf/asdf.png',
            ],
            [
                'h' => 50,
                'w' => 150,
                'path' => '/asdf/foo.png',
            ],
            [
                'h' => 100,
                'w' => 200,
                'path' => '/asdf/bar.png',
            ],
            [
                'h' => 300,
                'w' => 400,
                'path' => '/asdf/baz.png',
            ],

        ];

        foreach ($data as $row) {
            $cardImage = $this->serializer->denormalize($row, CardImages::class, null, [
                ObjectNormalizer::DISABLE_TYPE_ENFORCEMENT => false
            ]);

            $json = $this->serializer->serialize($cardImage, 'json');

            dump($cardImage, $json);
        }

        return new Response('<html><head></head></html></body></html>');

    }
}

Output: