Symfony 8.1 beta: DateTimeValueObjectTransformer is auto-tagged as property transformer and breaks container compile

[tacman]

API Platform version(s) affected

4.3.4

Description

When using api-platform/core 4.3.4 with Symfony 8.1 beta, the container fails to compile because the API Platform JSON Streamer DateTime value-object transformer service is also tagged as a property value transformer by Symfony's deprecation compiler pass.

The failure is:

In TransformerPass.php line 42:

  [Symfony\Component\DependencyInjection\Exception\InvalidArgumentException]
  The service "api_platform.jsonld.json_streamer.value_transformer.date_time" tagged "json_streamer.property_value_transformer" must implement "Symfony\Component\JsonStreamer\Transformer\PropertyValueTransformerInterface".

Installed versions from the affected project:

api-platform/core      v4.3.4
symfony/json-streamer v8.1.0-BETA1

The service is registered in src/Symfony/Bundle/Resources/config/json_streamer/common.php as:

$services->set('api_platform.jsonld.json_streamer.value_transformer.date_time', DateTimeValueObjectTransformer::class)
    ->tag('json_streamer.value_transformer', ['key' => \DateTimeInterface::class])
    ->tag('json_streamer.value_object_transformer');

In Symfony 8.1, json_streamer.value_transformer is deprecated. Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\DeprecateJsonStreamerValueTransformerTagPass adds json_streamer.property_value_transformer to services with the deprecated tag. Then Symfony\Component\JsonStreamer\DependencyInjection\TransformerPass validates json_streamer.property_value_transformer services and throws because Symfony\Component\JsonStreamer\Transformer\DateTimeValueObjectTransformer implements ValueObjectTransformerInterface, not PropertyValueTransformerInterface.

This looks related to #7839 and #7867, but those changes are already present in 4.3.4 and this still fails with Symfony 8.1.0-BETA1.

How to reproduce

Install API Platform with Symfony 8.1 beta packages, including symfony/json-streamer 8.1.0-BETA1, then boot the Symfony console/container.

For example:

php bin/console

The container compile fails before commands are listed.

Possible Solution

The DateTime service is a value-object transformer, so it probably should not be left with the deprecated json_streamer.value_transformer tag under Symfony 8.1 if FrameworkBundle converts that tag into json_streamer.property_value_transformer.

One possible direction is to conditionally avoid the deprecated tag for Symfony/json-streamer 8.1+, or otherwise prevent api_platform.jsonld.json_streamer.value_transformer.date_time from being processed as a property value transformer while preserving the \DateTimeInterface::class lookup needed by API Platform's JSON-LD stream writer.

Additional Context

Relevant Symfony code path:

• Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\DeprecateJsonStreamerValueTransformerTagPass
• Symfony\Component\JsonStreamer\DependencyInjection\TransformerPass

Exception trace starts at:

vendor/symfony/json-streamer/DependencyInjection/TransformerPass.php:42
Symfony\Component\JsonStreamer\DependencyInjection\TransformerPass->process()
vendor/symfony/dependency-injection/Compiler/Compiler.php:73

[soyuka]

Hi @tacman, thanks for the precise report — the trace and references to the relevant Symfony passes pinned this down quickly.

Confirming the diagnosis: #7839 and #7867 are both present in 4.3.4, but Symfony 8.1 changed the rules under our feet between those PRs being merged and 8.1.0-BETA1 shipping:

1. FrameworkBundle 8.1 (Symfony commit "[JsonStreamer] Handle value objects", 2026-03-06) now registers DateTimeValueObjectTransformer itself as .json_streamer.value_object_transformer.date_time, tagged only with json_streamer.value_object_transformer — never with the deprecated json_streamer.value_transformer.
2. FrameworkBundle 8.1 also ships DeprecateJsonStreamerValueTransformerTagPass, which appends json_streamer.property_value_transformer to every service still carrying the deprecated json_streamer.value_transformer tag (skipping only those that already carry the property-value tag — it does not check for json_streamer.value_object_transformer).

#7867 left both tags on our DateTime registration. The deprecation pass therefore upgrades the deprecated tag, then TransformerPass rejects the service because DateTimeValueObjectTransformer implements ValueObjectTransformerInterface, not PropertyValueTransformerInterface.

Fix is in #7955: gate our registration on the absence of DeprecateJsonStreamerValueTransformerTagPass (so we still register it ourselves on the json-streamer 8.1 + framework-bundle <8.1 combo allowed by our composer constraints) and drop the deprecated tag from the registration we still emit.