I have a ZF1 project that was developed used the lean startup approach. I'm now ready to move into a more evolved project as I know what my users want, but I really want to develop using better techniques. I've decided to move from ZF1 to ZF2 for support reasons and this is where I'm at:
API(Client) - I have a "push only' API that users use to send me data API(Admin) - The admins can consume the data pushed using a variety of metrics and aggregates
The API for clients is restful but just pushes into a Redis job queue currently and is processed via cron. This removes the need for clients to wait for their data to be inserted and their requests are returned immediately.
The API for admin is currently not restful and is actually consumed inside of the application only. I think that this is okay as I don't want to have a single page frontend or API consuming front end. I would rather data be returned immediately by the server.
This leaves me with the question of whether I have an API Service Module which provides all of the Models (Doctrine2 ODM POPOs), mappers, filters, and a service layer to access it all and then the controllers that need it can consume the API without making HTTP requests (via service calls).
Is this the proper way to structure or is there a more refined and acceptable approach? I like the service layer in general as testing will be more accurate and all clients / admins are using the same API (if it updates it is essentially updated immediately across the board as there are not separate projects).
I think the module you think of doesn't need to have an own built service layer which only forwards to another service (like Doctrine entitymanager or something else), it rather should only provide the other modules the required services by configuring the DI and encapsulate the required classes (like models, mappers, filters, ...).
In my company for this purpose there is always an 'Application' module (like it was in the early tutorials of ZF2). I dont know if this is still best practice, but there are some serious benefits regarding maintainance and structure.
You should consider defining a module dependency in the 'consuming' modules (like Client-API or Admin-UI).
It is also worth to take a look at the Doctrine library and DoctrineModule implementation, to get a feeling what a module should provide and where it makes sense to only provide a library.