Normalize a collection with API Platform - symfony

Question

I manage to get a filtered collection of my Note entities with API Platform, using the #ApiFilter(SearchFilter::class) annotation.
Now I want to convert the json response which is an hydra collection
Example :
{
"#context": "/api/contexts/Note",
"#id": "/api/notes",
"#type": "hydra:Collection",
"hydra:member": []
}
to an archive containing one file by Note and return its metadata.
Example :
{
"name": "my_archive.zip",
"size": 12000,
"nb_of_notes": 15
}
I want to keep the SearchFilter benefits. Is the Normalization the good way to go ?
How to declare the normalizer ? How to access the collection/array of Notes in my normalize() method ?

Answer 1

According to the documentation symfony custom_normalizer , you can create a custom normalizer for your Note entity (for example NoteNormalizer). In the supportsNormalization method your must precise that the normalizer will only affect your Note entity by providing Note entity class. So in the normalize method, you will get each item of your ArrayCollection of Note. If you want to be sure, you can make a dump to $data variable (dd($data)) inside this normalize method, and you will have the first element of you ArrayCollection.
that's how I tried to understand it.
namespace App\Serializer;
use App\Entity\Note;
use Symfony\Component\Serializer\Normalizer\ContextAwareNormalizerInterface;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
class NoteNormalizer implements ContextAwareNormalizerInterface
{
private $normalizer;
public function __construct(ObjectNormalizer $normalizer) // Like in documentation you can inject here some customer service or symfony service
{
$this->normalizer = $normalizer;
}
public function normalize($topic, $format = null, array $context = [])
{
$data = $this->normalizer->normalize($topic, $format, $context);
$data['name'] = 'some name';
$data['size'] = 12000;
$data['nb_of_notes'] = 15;
return $data;
}
public function supportsNormalization($data, $format = null, array $context = [])
{
return $data instanceof Note;
}
}
Or if you want you can use this command to generate it automatically :
php bin/console make:serializer:normalizer
And give the name : NoteNormalizer

Answer 2

Simply create a "collection Normalizer" :
note: works the same for vanilla symfony projects too.
namespace App\Serializer;
use App\Entity\Note;
use Symfony\Component\Serializer\Normalizer\ContextAwareNormalizerInterface;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
use Symfony\Component\Serializer\Normalizer\NormalizerAwareTrait;
class NoteCollectionNormalizer implements ContextAwareNormalizerInterface, NormalizerAwareInterface
{
use NormalizerAwareTrait;
public function supportsNormalization($data, $format = null, array $context = []): bool
{
if(!is_array($data) || (!current($data) instanceof Note)) {
return false;
}
return true;
}
/**
* #param Note[] $collection
*/
public function normalize($collection, $format = null, array $context = [])
{
// ...
}
}