Scala/Implicit/Playframework/Action: Wrapping Action Function - scala

Question

It's exactly a Scala question, but it is in the context of the PlayFramework Action:
An Action takes something in the form (play.api.mvc.Request => play.api.mvc.Result). And then you'll pass a block like:
{ request =>
Ok(views.html.index("Your new application is ready."))
}
Now I have defined a function with the same signature. One with and one without implicit for request.
def WithUser2(request: Request[AnyContent])(block: (Request[AnyContent]) => Result):Result = {
block(request)
}
def WithUser3(block: (Request[AnyContent]) => Result)(implicit request: Request[AnyContent]):Result = {
block(request)
}
I'm calling it this way now (2 versions):
def index2 = Action { implicit request => WithUser2(request) { request =>
Ok(views.html.index("Your new application is ready. " ))
}}
def index3 = Action ( implicit request => WithUser3 { request =>
Ok(views.html.index("Your new application is ready. " ))
})
Is there a way to directly attach my function to Action? I mean without placing implicit request => before WithUserX so that my function replaces the complete block after Action directly? Now my function is inside the block and I think this is the problem why I need to pass request forward. So I need a way to get rid of the block around my function.

Answer 1

It's not 100% clear what you're trying to do, because WithUserX essentially does nothing special. It seems like you're trying to make your own Action, and for that we have Action Composition.
If you were to define a new Action like this:
object WithUser extends ActionBuilder[Request] {
def invokeBlock[A](request: Request[A], block: (Request[A]) => Future[Result]) = {
// Do something special maybe?
block(request)
}
}
You could then use it like this:
def index = WithUser { request =>
...
Ok("Ok!")
}
This would be much better than trying to stuff it within the stock Action, when it doesn't need to be.