How to setup my UserService using the cake pattern inside of play? - scala

Question

Currently I am using guice to wireup my UserService inside of a controller like:
#Singleton
class UserController #Inject()(userService: UserService) extends Controller {
def show(userId: Int) {
val user = userService.get(userId)
Ok("hello " + user.name)
}
}
My UserService looks like:
abstract class UserService {
def get(userId: Int): User
}
class UserServiceImpl #Inject()(val userDao: UserDao) extends UserService {
def get(userId: Int): User = {
// ....
}
}
If I wanted to drop guice as a dependency and use the cake pattern, what would the code look like and how would I integrate this into Play so I could use this service in my Controllers?

Answer 1

Here's a suggestion with package names to give you an idea of how to organize all of this.
package controllers.users
trait UserController extends Controller {
this: UserService =>
def show(userId: Int) = {
val user = this.get(userId)
Ok("hello " + user.name)
}
}
package services.users
trait UserService {
def get(userId: Int): User
}
package services.users.impl
trait UserServiceImpl extends UserService {
def get(userId: Int) = { /*implementation*/ }
}
package controllers
object UserController extends UserController with UserServiceImpl
You can put your services and your controller traits anywhere you like in the project. You should put your controller object directly in the controllers package to make routing most convenient.