Message Type Specific Delivery Rules

You may want to enforce some specific rules about how Jasper publishes messages on a message type by message type basis. The most common example is shown below:

// Any message of this type should be successfully
// delivered within 10 seconds or discarded
[DeliverWithin(10)]
public class StatusMessage
{
}

Custom Attributes

If you really want to, you can write your own custom attribute to modify how Jasper sends out a message by subclassing the [ModifyEnvelope] attribute. The attribute shown in the previous sample is itself implemented like that:

public class DeliverWithinAttribute : ModifyEnvelopeAttribute
{
    private readonly int _seconds;

    public DeliverWithinAttribute(int seconds)
    {
        _seconds = seconds;
    }

    public override void Modify(Envelope envelope)
    {
        envelope.DeliverBy = DateTimeOffset.UtcNow.AddSeconds(_seconds);
    }
}

By Endpoint

You may want to say that all the envelopes sent to a specific endpoint should have the same customization. As an example, let's say that you're sending rapid fire status messages to some kind of monitoring tool where you're not terribly worried about any particular message getting dropped and each individual message will soon be obsolete. In this case you might want to set a message expiration date on every message sent to this endpoint. You can do that with endpoint specific rules like this:

public class MonitoringDataPublisher : JasperOptions
{
    public MonitoringDataPublisher()
    {
        Endpoints.PublishAllMessages()
            .ToPort(2222)

            // Set a message expiration on all
            // outgoing messages to this
            // endpoint
            .CustomizeOutgoing(env => env.DeliverWithin(2.Seconds()));
    }
}