Materialized View Generator

GenerateMaterializedViewAttribute creates a typed MaterializedView<TState,TEvent> factory from annotated projection handler methods.

[GenerateMaterializedView(typeof(OrderReadModel), typeof(OrderEvent), FactoryName = "CreateView", ViewName = "order-read-model")]
public static partial class GeneratedOrderMaterializedView
{
    [MaterializedViewHandler(typeof(OrderPlaced), Order = 10)]
    private static OrderReadModel ApplyPlaced(OrderReadModel state, OrderPlaced @event)
        => state with { OrderId = @event.OrderId };
}

The generated factory is equivalent to:

MaterializedView<OrderReadModel, OrderEvent>
    .Create("order-read-model")
    .WithHandler<OrderPlaced>(ApplyPlaced, 10)
    .Build();

Diagnostics:

• PKMV001: host type must be partial.
• PKMV002: at least one [MaterializedViewHandler] method is required.
• PKMV003: handler methods must be static and return the state type, or ValueTask<TState> with a CancellationToken.