Subscription Options

The SubscriptionOptions configured as HopperOptions.Subscription represent common options related to subscriptions.

Any implementation of the ISubscriptionService interface should make use of these options to register, or ensure, any subscriptions:

services.AddHopper(builder => 
{
    builder.Options.Subscription.Mode = SubscriptionMode.Standard; // default
    
    // add subscription to message types directly; else below options on builder
    builder.Options.Subscription.MessageTypes.Add(typeof(Event1).FullName);

    // using type
    builder.AddSubscription(typeof(Event1));
    builder.AddSubscription(typeof(Event2));

    // using a full type name
    builder.AddSubscription(typeof(Event1).FullName);
    builder.AddSubscription(typeof(Event2).FullName);

    // using a generic
    builder.AddSubscription<Event1>();
    builder.AddSubscription<Event2>();
});

And the JSON configuration structure:

{
  "Shuttle": {
    "Hopper": {
      "Subscription": {
        "Mode": "Standard",
        "CacheTimeout": "00:05:00",
        "MessageTypes": [
          "message-type-a",
          "message-type-b"
        ]
      }
    }
  }
}

Options

Option	Default	Description
Mode	Standard	Indicates how subscriptions are dealt with: - Standard is the default and will subscribe to the given message type(s) if they have not been subscribed to yet. - FailWhenMissing will check to see that the subscription exists and if not will throw an exception. - Disabled will simply ignore the subscription request.
CacheTimeout	null	How long event subscribers should be cached for before refreshing the list.

When moving to a non-development environment it is recommended that you make use of the FailWhenMissing option for the Mode.