Publish-Subscribe pattern

If you are coming from other popular mediator libraries, you may be looking for a way to implement the publish-subscribe pattern with Immediate.Handlers. A common use case is implementing domain events.

Immediate.Handlers fully supports this pattern, but it intentionally does not provide a built-in Publisher abstraction. Maintaining an opinionated publish-subscribe implementation is out of scope and would limit the flexibility required by different projects.

An example is provided here of a simple Publisher which works for many cases.

public sealed class Publisher<TNotification>(
    IServiceProvider serviceProvider
)
{
    public async ValueTask Publish(TNotification notification)
    {
        foreach (var handler in serviceProvider.GetServices<IHandler<TNotification, ValueTuple>>())
        {
            await handler.Handle(notification);
        }
    }
}

Finally, this implementation can simply be registered as singleton service:

services.AddSingleton(typeof(Publisher<>));