Model and Forms

In Play Framework, we use Scala sealed classes, case classes, and case objects to define model objects. Scala case classes are immutable and serializable.

Consider the following code, for example:

sealed class Message 
case object SuccessMessage extends Message  
case object FailureMessage extends Message 

We also define some Forms using the Play Form API. Refer to the Play Framework Form-based web application section of this chapter for more information.

Other components – services and repositories

We use some other user-defined components, such as services, repositories, and Utils, to decouple the code from controllers.

We define our business logic in Services and Data Access logic (such as DAO components...