Not Rewindable

Mark a projection as not rewindable (forward-only) using [NotRewindable]:

C#

using Cratis.Chronicle.Events;
using Cratis.Chronicle.Keys;
using Cratis.Chronicle.Projections.ModelBound;

[EventType]
public record MbNotRewindableAuditEvent(string Message, DateTimeOffset OccurredAt);

[NotRewindable]
public record MbNotRewindableAuditLog(
    [Key]
    Guid Id,

    [SetFrom<MbNotRewindableAuditEvent>(nameof(MbNotRewindableAuditEvent.Message))]
    string Message,

    [SetFrom<MbNotRewindableAuditEvent>(nameof(MbNotRewindableAuditEvent.OccurredAt))]
    DateTimeOffset Timestamp);

Kotlin

Kotlin does not support this workflow yet.

Java

Java does not support this workflow yet.

Elixir

Elixir does not support this workflow yet.

TypeScript

import { eventType, Guid, notRewindable, readModel, setFrom } from '@cratis/chronicle';

@eventType()
class MbNotRewindableAuditEvent {
    message = '';
    occurredAt = new Date();
}

@readModel()
@notRewindable
class MbNotRewindableAuditLog {
    id: Guid = Guid.empty;

    @setFrom(MbNotRewindableAuditEvent, 'message')
    message = '';

    @setFrom(MbNotRewindableAuditEvent, 'occurredAt')
    timestamp = new Date();
}

When to use

• Audit logs or append-only data
• Projections that should never be replayed from scratch
• Time-sensitive data where replay would be incorrect

Best practices

• Use for append-only scenarios where historical replay would be problematic
• Consider carefully as this removes the ability to rebuild the projection from scratch
• Ensure you have alternative recovery strategies if the projection becomes corrupted