Purely Functional Play Framework Application

There is no doubt that Play is a wonderful Web framework. It has many features and embodies the term “scalable”, as it can be used in a multitude of scenarios, from a small-scale throwaway app to a large-scale application. With its long history, and an official support, it is no overstatement to say that it’s the de facto standard Web framework of Scala.

However, I do have some bones to pick with Play. Among them is runtime Dependency Injection (DI) using Google Guice. It may well be an effective tool during large-scale applications development, but it’s also a cause of endless annoyance that sometimes makes you doubt if you are indeed still coding in Scala. Heaven forbid should you also choose to combine it with a Mock library during testing; you’ll come across NullPointerExceptions faster than the type system can save you.

In this session, I will propose an alternative method of implementing the Play application using functional programming libraries such as Cats, doobie, Monix, and Monocle. I will use these to build pure logics in a type-safe manner, such that they can be analyzed from any angles that you choose to slice and dice.

Unfortunately, this method will not be a panacea that suits all tastes, but I hope it serves as an energy drink for those who are tired of implementing boring apps.

Session length

40 minutes

Language of the presentation

Japanese

Target audience

Advanced: For those who are experts in the field

Who is your session intended to

Those interested in practical functional programming
Those frustrated with runtime Dependency Injection

Speaker

Naoki Aoyama - @aoiroaoino (Septeni Original, Inc)