What is the meaning of the variable before "=>" in a Scala Action definition?

Question

This is a basic controller action in play framework with scala. Can you please explain what is the request variable. Is it the action parameter?

def echo = Action { request =>
          Ok("Got request [" + request + "]")
        }

The title should give some clue what the question is about. For instance "what is the mening of the variable before "=>" in a scale Action definition?" — Dirk Horsten, Aug 02 '18 at 19:18
I don't know... Does [Scala anonymous function syntax and return type](https://stackoverflow.com/questions/41826610/scala-anonymous-function-syntax-and-return-type) cover it, or do you want to know anything more specific about Scala Play Requests what is not covered [by the api](https://www.playframework.com/documentation/2.0.2/api/scala/index.html#play.api.mvc.Action$)? — Andrey Tyukin, Aug 02 '18 at 19:35

score 1 · Accepted Answer · answered Aug 02 '18 at 19:24

Well... let me add more information to it.

def echo = Action { request =>
  Ok("Got request [" + request + "]")
}

is actually,

def echo = Action({ request =>
  Ok("Got request [" + request + "]")
})

is actually,

def echo = Action.apply({ request =>
  Ok("Got request [" + request + "]")
})

is actually,

def echo = Action.apply((request: Request) => {
  Ok.apply("Got request [" + request + "]")
})

And, if you are still finding it confusing... then you need to read basics of Scala.

1 Answers1