DKNet

Declare events for persistence operations

Part of DKNet.EfCore.Abstractions. Apply repeatable, non-inherited [RaisesEvent] declarations to an entity for create, update or delete payloads.

Use the console-project setup in the Quick Start, then replace Program.cs with this example.

using DKNet.EfCore.Abstractions.Entities;
using DKNet.EfCore.Abstractions.Events;

Console.WriteLine(EventNameComposer.Compose(nameof(Customer), "Contact",
    [nameof(Customer.Email)], (int)EventOperations.Updated));
// CustomerContactEmailUpdatedEvent

[RaisesEvent("Contact", EventOperations.Updated, nameof(Email),
    Include = new[] { nameof(Id), nameof(Email) })]
public sealed class Customer : Entity
{
    public string Email { get; set; } = "";
}

EventOperations is a flags enum: Created = 1, Updated = 2, Deleted = 4. EventNameComposer appends entity, optional label, distinct ordinal-sorted properties, operations in Created/Updated/Deleted order, then Event.

⚙️ Configuration reference

Form	Example	Payload owner
Type-naming	[RaisesEvent(typeof(CustomerPayload), EventOperations.Created)]	Existing [GenerateDto(typeof(Customer))] record.
Label	[RaisesEvent("Contact", EventOperations.Updated)]	DtoGenerator composes a record name with the label.
Label-less	[RaisesEvent(EventOperations.Created)]	DtoGenerator composes a record name without a label.

Member	Type	Default	Effect
EventType / Label	Type? / string?	null when not supplied	Select named payload or label segment.
Operations	EventOperations	required	Operations that qualify.
Properties	IReadOnlyList<string>	empty	Any direct change qualifies for Updated; a list narrows it.
Include / Exclude	string[]	[]	Shape composed payloads; never change their names.

A nonempty Include overrides global DtoGeneratorExclusions; navigations are still omitted. Without Include, global exclusions also apply to composed payloads. See DtoGenerator for build diagnostics and payload generation.

🧱 Where it fits

DtoGenerator validates declarations and emits convention payloads at build time. Events reads the same declarations through the save hook at runtime and maps entities to payloads. EventNameComposer is shared as linked source between the two assemblies.

⚠️ Gotchas & limits

• The example prints a name using only Abstractions. It generates no payload until you reference DtoGenerator and publishes nothing until Events is registered.
• A string argument is a label segment, not a literal event type name. Revisit declarations when upgrading from the earlier literal-name form.
• Update narrowing checks direct properties only. Owned-value changes alone do not mark the owner Modified.
• Empty operation flags, invalid names, collisions and invalid property names are diagnosed by DtoGenerator. Include and Exclude cannot both be nonempty, and are invalid on the type-naming form.

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