Make external event payloads strongly typed

[tnotheis]

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• I added/updated unit tests.
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So far the payloads of the external events have been anonymous objects. This isn't ideal, so this PR introduces a subclass of ExternalEvent for each external event type.

[HunorTotBagi]

I noticed that in DomainEvents.Incoming most of the files we have a Handle method and a CreateExternalEvents but in

• IdentityDeletionProcessStartedDomainEventHandler
• IdentityDeletionProcessStatusChangedDomainEventHandler
• RelationshipStatusChangedDomainEventHandler

we don't follow this "pattern". So for consistency sake I would refactor the above three mentioned files to have a Handle and a CreateExternalEvents method. What do you think about this?

[HunorTotBagi]

I noticed that in DomainEvents.Incoming most of the files we have a Handle method and a CreateExternalEvents but in

• IdentityDeletionProcessStartedDomainEventHandler
• IdentityDeletionProcessStatusChangedDomainEventHandler
• RelationshipStatusChangedDomainEventHandler

we don't follow this "pattern". So for consistency sake I would refactor the above three mentioned files to have a Handle and a CreateExternalEvents method. What do you think about this?

@tnotheis Thoughts on this? It seems you missed this one.

[tnotheis]

@HunorTotBagi Sorry, you're right. I didn't see that.

I just fixed it. I also renamed the methods so they contain the name of the event that is created. So if there is another external event created by the same domain event handler, we would do this in another private method.

Further, I moved the try/catch block to the Handle method, so that we don't have to catch exceptions in all of the private methods.

Btw: I think we could even remove the try/catch blocks, because the EventBus classes already log descriptive error messages. But I will not remove them in this PR.

[HunorTotBagi]

@HunorTotBagi Sorry, you're right. I didn't see that.

I just fixed it. I also renamed the methods so they contain the name of the event that is created. So if there is another external event created by the same domain event handler, we would do this in another private method.

Further, I moved the try/catch block to the Handle method, so that we don't have to catch exceptions in all of the private methods.

Btw: I think we could even remove the try/catch blocks, because the EventBus classes already log descriptive error messages. But I will not remove them in this PR.

Thanks, I like the changes.

I also noticed that the naming of the parameters in the Handle and in the private methods are all different for example we can see domainEvent, @event and integrationEvent. We should choose in what method which naming to use and apply all over them.

[tnotheis]

I also noticed that the naming of the parameters in the Handle and in the private methods are all different for example we can see domainEvent, @event and integrationEvent. We should choose in what method which naming to use and apply all over them.

Done