Subresources doesn't respect relation field type

[divine]

API Platform version(s) affected: 3.1.12

Description
When querying relation results in API Platform version 3.1.12, the subresources do not respect the relation field type.

Possibly related to issue #5269.

How to reproduce

Let's say we've followed up documentation and created a similar Question to Answer relation subresource.

/src/Document/Question.php

<?php

namespace App\Document;

use ApiPlatform\Metadata\ApiResource;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ODM\MongoDB\Mapping\Annotations as MongoDB;

#[MongoDB\Document(collection: 'questions')]
#[ApiResource]
class Question
{
    #[MongoDB\Id]
    public $id;

    #[MongoDB\Field(type: 'string')]
    public ?string $text = null;

    #[MongoDB\ReferenceMany(storeAs: 'id', targetDocument: Answer::class, mappedBy: 'question')]
    public Collection|iterable $answers;

    public function __construct()
    {
        $this->answers = new ArrayCollection();
    }

    public function getId()
    {
        return $this->id;
    }

    public function getText(): ?string
    {
        return $this->text;
    }

    public function setText(string $text): self
    {
        $this->text = $text;

        return $this;
    }

    public function getAnswers()
    {
        return $this->answers;
    }

    public function setAnswers($answers): self
    {
        $this->answers = $answers;

        return $this;
    }
}

src\Document\Answer.php

<?php

namespace App\Document;

use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\Delete;
use ApiPlatform\Metadata\GetCollection;
use ApiPlatform\Metadata\Link;
use ApiPlatform\Metadata\Patch;
use ApiPlatform\Metadata\Post;
use Doctrine\ODM\MongoDB\Mapping\Annotations as MongoDB;

#[MongoDB\Document(collection: 'answers')]
#[ApiResource(
    uriTemplate: '/questions/{id}/answers',
    operations: [
        new GetCollection(),
        new Post(),
        new Patch(),
        new Delete(),
    ],
    uriVariables: [
        'id' => new Link(toProperty: 'question', fromClass: Question::class),
    ],
)]
class Answer
{
    #[MongoDB\Id]
    public $id;

    #[MongoDB\Field(type: 'string')]
    public ?string $text = null;

    #[MongoDB\ReferenceOne(storeAs: 'id', targetDocument: Question::class)]
    public ?Question $question;

    public function getId()
    {
        return $this->id;
    }

    public function getText(): ?string
    {
        return $this->text;
    }

    public function setText(string $text): self
    {
        $this->text = $text;

        return $this;
    }

    public function getQuestion()
    {
        return $this->question;
    }

    public function setQuestion(?Question $question): self
    {
        $this->question = $question;

        return $this;
    }
}

Which creates a query:

{
    "aggregate": "answers",
    "pipeline": [
        {
            "$lookup": {
                "from": "questions",
                "as": "question_lkup",
                "localField": "question",
                "foreignField": "_id"
            }
        },
        {
            "$match": {
                "question_lkup._id": "647b60f72a3e4fac1f08b752"
            }
        },
        {
            "$sort": {
                "_id": {
                    "$numberInt": "1"
                }
            }
        },
        {
            "$facet": {
                "results": [
                    {
                        "$skip": {
                            "$numberInt": "0"
                        }
                    },
                    {
                        "$limit": {
                            "$numberInt": "30"
                        }
                    }
                ],
                "count": [
                    {
                        "$count": "count"
                    }
                ]
            }
        }
    ],
    "cursor": {}
}

Possible Solution
The subresources should respect the relation field type, ensuring that the correct related entities are returned in the query results.

The query should be like:

"$match": {
   "question_lkup._id":  ObjectId("647b60f72a3e4fac1f08b752")
}

Additional Context

Let me know if I can help somehow.

[divine]

Quite interesting findings while trying to fix the problem.

The problematic lines are here which doesn't take for relations types:

core/src/Doctrine/Odm/State/LinksHandlerTrait.php

Lines 92 to 104 in 4ef0ef8

	if ($lookupProperty && $classMetadata->hasAssociation($lookupProperty)) {
	$aggregation->lookup($lookupProperty)->alias($lookupPropertyAlias);
	}
	if ($toProperty) {
	foreach ($identifierProperties as $identifierProperty) {
	$aggregation->match()->field(sprintf('%s.%s', $lookupPropertyAlias, 'id' === $identifierProperty ? '_id' : $identifierProperty))->equals($this->getIdentifierValue($identifiers, $hasCompositeIdentifiers ? $identifierProperty : null));
	}
	} else {
	foreach ($identifierProperties as $identifierProperty) {
	$aggregation->match()->field($identifierProperty)->equals($this->getIdentifierValue($identifiers, $hasCompositeIdentifiers ? $identifierProperty : null));
	}
	}

To address this problem, we can add a function similar to the one used in this file:

core/src/Doctrine/Odm/Filter/SearchFilter.php

Lines 164 to 171 in 4ef0ef8

	$type = $metadata->getTypeOfField($field);
	if (!MongoDbType::hasType($type)) {
	return $value;
	}
	if (MongoDbType::STRING !== $type) {
	return MongoDbType::getType($type)->convertToDatabaseValue($value);
	}

However, we need to know that $classMetadata->getTypeOfField($lookupProperty); returns one as it's relation and we need to add the check like from this file:

core/src/Doctrine/Odm/PropertyHelperTrait.php

Line 69 in 4ef0ef8

if (($isOwningSide = $referenceMapping['isOwningSide']) && MongoDbOdmClassMetadata::REFERENCE_STORE_AS_ID !== $referenceMapping['storeAs']) {

Something like this as the fix for relation:

        $associationAsObject = false;

        if ($lookupProperty && $classMetadata->hasAssociation($lookupProperty)) {

            $referenceMapping = $classMetadata->getFieldMapping($lookupProperty);
            $associationAsObject = MongoDbOdmClassMetadata::REFERENCE_STORE_AS_ID === $referenceMapping['storeAs'] ?? false;

            $aggregation->lookup($lookupProperty)->alias($lookupPropertyAlias);
        }

        if ($toProperty) {
            foreach ($identifierProperties as $identifierProperty) {
                $aggregation->match()->field(sprintf('%s.%s', $lookupPropertyAlias, 'id' === $identifierProperty ? '_id' : $identifierProperty))->equals(
                    $this->getFieldType(
                        $associationAsObject ? MongoDbType::OBJECTID : $classMetadata->getTypeOfField($toProperty),
                        $this->getIdentifierValue($identifiers, $hasCompositeIdentifiers ? $identifierProperty : null)
                    )
                );
            }
        }
            

And the getFieldType function:

private function getFieldType($type, $value){

        if (!MongoDbType::hasType($type)) {
            return $value;
        }
        if (MongoDbType::STRING !== $type) {
            return MongoDbType::getType($type)->convertToDatabaseValue($value);
        }

        return $value;
    }

The queries now works great as expected, I'll send the PR to just see how it works, I understand it might be to dirty...

However, posting now to answers endpoint doesn't add the question id field to the answers which is weird... Is that another bug or I'm blind now 🙈

curl -X 'POST' \
  'https://localhost/questions/:id/answers' \
  -H 'accept: application/ld+json' \
  -H 'Content-Type: application/ld+json' \
  -d '{
  "text": "Hello this is answer"
}'

Thank you very much!

[divine]

Well, adding a type to the Id field resolved my problem.

#[MongoDB\Id(type: 'object_id')]

Thanks!