Pass the message to apply methods of projections - #922
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Decisions sometimes depend on metadata, e.g. when an event was recorded (retention periods, token expiry). Apply methods of a BasicProjection only got the state and the event, so there was no way to reach it. They can now take the Message as an optional third parameter. A third parameter with a different type is reported as ApplyMethodDetectionError.
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DanielBadura
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We should maybe also think about adding this to normal aggregate applies?
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| ```php | ||
| use Patchlevel\EventSourcing\Attribute\Apply; | ||
| use Patchlevel\EventSourcing\Identifier\Uuid; | ||
| use Patchlevel\EventSourcing\Message\Message; | ||
| use Patchlevel\EventSourcing\Projection\BasicProjection; | ||
| use Patchlevel\EventSourcing\Store\Header\RecordedOnHeader; | ||
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| final class LastCheckIn extends BasicProjection | ||
| { | ||
| public function __construct( | ||
| private readonly Uuid $hotelId, | ||
| ) { | ||
| } | ||
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| public function initialState(): DateTimeImmutable|null | ||
| { | ||
| return null; | ||
| } | ||
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| /** @return list<string> */ | ||
| protected function tagFilter(): array | ||
| { | ||
| return ["hotel:{$this->hotelId->toString()}"]; | ||
| } | ||
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| #[Apply] | ||
| public function applyGuestIsCheckedIn( | ||
| DateTimeImmutable|null $state, | ||
| GuestIsCheckedIn $event, | ||
| Message $message, | ||
| ): DateTimeImmutable { | ||
| return $message->header(RecordedOnHeader::class)->recordedOn; | ||
| } | ||
| } | ||
| ``` | ||
| ::: |
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not sure how this will look rendered tbh :D
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Some decisions depend on metadata, like when an event was recorded. The dcb.events examples need this for the username retention period, the price grace period and the opt-in token expiry. Apply methods of a
BasicProjectiononly got the state and the event, so there was no way to get there.Apply methods can now take the
Messageas an optional third parameter:If the third parameter has another type, the projection throws an
ApplyMethodDetectionErrorinstead of failing later with a type error.