We recognize this problem; all fields for types in app services are set to non-optional. We will change this behavior in a next release of Mendix 5; it's in the top of our backlog. Thanks for your input!
While this might be a different issue it does apply to the appservices which is why i'll post it here.
I noticed that if use an entity within different appservice actions this entity is actually imported multiple times. E.g. I have an account entity that i use in each action as input parameter. This results in an domain model with account, account1, account2 etc.
Is this a known issue or is that intended to happen and am i doing something wrong?
To Pieter van de Braak: Be careful when upgrading to Mx5.2 when it comes to app services.
I just logged a ticket [100455] ; that might affect your work too:
When using AppServices in 5.1 we can return list of objects (Releases) that are related to list of Objects (Projects)
After converting it to Mx5.2 The relational objects (Projects) are not showin in the Model, while the app services has not changed. See screenshot.