Api Platform conference
Register now
Guides Hook a Persistence Layer with a Processor
API Platform Conference
September 18-19, 2025 | Lille & online

The international conference on the API Platform Framework

Final tickets available before registration closes.

Be part of the very first meeting with the FrankenPHP elePHPant plushies in Lille.

This edition is shaping up to be our biggest yet — secure your seat now before we sell out.

Only a few tickets left!
Guide

Hook a Persistence Layer with a Processor

design

Hook a Persistence Layer with a Processor

// src/App/ApiResource.php
namespace App\ApiResource;
use ApiPlatform\Metadata\ApiResource;
use App\State\BookProcessor;
use App\State\BookProvider;
We use a BookProcessor as the ApiResource::processor option.
#[ApiResource(processor: BookProcessor::class, provider: BookProvider::class)]
class Book
{
    public function __construct(public string $id, public string $title)
    {
    }
}

// src/App/State.php
namespace App\State;
use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProcessorInterface;
use ApiPlatform\State\ProviderInterface;
use App\ApiResource\Book;
use Ramsey\Collection\CollectionInterface;
The BookProcessor is where we can handle a persistence layer. In this processor we’re storing the JSON representation of the book in a file.
final class BookProcessor implements ProcessorInterface
{
    /**
     * @param Book $data
     */
    public function process($data, Operation $operation, array $uriVariables = [], array $context = []): Book
    {
        $id = $uriVariables['id'] ?? $data->id;
        file_put_contents(sprintf('book-%s.json', $id), json_encode($data));
        return $data;
    }
}
final class BookProvider implements ProviderInterface
{
    public function provide(Operation $operation, array $uriVariables = [], array $context = []): ?Book
    {
        if ($operation instanceof CollectionInterface) {
            throw new \RuntimeException('Not supported.');
        }
        $file = sprintf('book-%s.json', $uriVariables['id']);
        if (!file_exists($file)) {
            return null;
        }
        $data = json_decode(file_get_contents($file));
        return new Book($data->id, $data->title);
    }
}

// src/App/Playground.php
namespace App\Playground;
use Symfony\Component\HttpFoundation\Request;
function request(): Request
{
    return Request::create(uri: '/books', method: 'POST', server: ['CONTENT_TYPE' => 'application/ld+json'], content: json_encode(['id' => '1', 'title' => 'API Platform rocks.']));
}

You can also help us improve this guide.

Made with love by

Les-Tilleuls.coop can help you design and develop your APIs and web projects, and train your teams in API Platform, Symfony, Next.js, Kubernetes and a wide range of other technologies.

Learn more

Copyright © 2023 Kévin Dunglas

Sponsored by Les-Tilleuls.coop