DDD. Where do user configurable settings belong?

Question

I'm working on my first "real" DDD application.

Currently my client does not have access to my domain layer and requests changes to the domain by issuing commands.

I then have a separate (flattened) read model for displaying information (like simple CQRS).

I'm now working on configuration, or specifically, settings that the user configures. Using a blog application as an example, the settings might be the blog title or logo.

I've developed a generic configuration builder that builds a strongly typed configuration object (e.g. BlogSettings) based on a simple key value pair collection. I'm stuck on whether these configuration objects are part of my domain. I need access to them from the client and server.

I'm considering creating a "Shared" library that contains these configuration objects. Is this the correct approach?

Finally where should the code to save such configuration settings live? An easy solution would be to put this code in my Domain.Persistence project, but then, if they are not part of the domain, should they really be there?

Thanks,

Ben

Answer 1

User configurable settings belong to domain if they are strongly typed and modeled based on ubiquitous language, i.e. 'BlogSettings'. The only difference between settings and other domain objects is that conceptually settings are 'domain singletons'. They don't have a life cycle like other Entities and you can only have one instance.

Generic configuration builder belongs to Persistence just like the code that is responsible for saving and reading settings.