Slim Play App

Wanna build a really, really slim Play project?

This project demonstrates how you can easily build a non-blocking, threadsafe, and fast Play app without having to use the default routes file. The end-result should be familiar territory for people who are used to the simplicity of Sinatra/Bottle but want to take advantage of Scala's concurrent, type-safe and scalable nature.

Templates

In case you want to get up and running right away, use the following Slim-Play templates:

For Giter8: $ g8 lloydmeta/slim-play

How to run

1. Git clone this project or use a template
2. sbt run from the project's root directory
3. Open a browser and hit:

• Hello $name endpoint
• Async Sqrt calculator

How it was built

All I did was:

1. Use sbt new to generate a new Play app ($ sbt new playframework/play-scala-seed.g8 --name=slim-play)
2. Delete the auto-generated controller, public, and view directories (won't be using them)
3. Create a AppLoader.scala file in the ./app directory, which holds an ApplicationLoader and the router, which is super simple:

val router = Router.from {
  case GET(p"/hello/$to") => Action {
    Ok(s"Hello $to")
  }
  /*
   Use Action.async to return a Future result (sqrt can be intense :P)
   Note the use of double(num) to bind only numbers (built-in :)
   */
  case GET(p"/sqrt/${double(num)}") => Action.async {
    Future {
      Ok(Math.sqrt(num).toString)
    }
  }
}

4. Add play.application.loader=AppLoader to ./conf/application.conf so that Play knows to load our custom app (that contains our simple router)

More info

The following links may be useful for further understanding on what is happening here:

1. Official Play docs on String Interpolating Routing DSL
2. Official Play docs on Compile-time dependency injection