play/scala , implicit request => what is meaning?
playframework, scala
Solution
`play.api.mvc.Action` has helper methods for processing requests and returning results. One if it's `apply` overloads accepts a `play.api.mvc.Request` parameter:
def apply(request: Request[A]): Future[Result]
By marking the request parameter as `implicit`, you're allowing other methods which implicitly require the parameter to use it. It also stated in the Play Framework documentation:
It is often useful to mark the request parameter as implicit so it can be implicitly used by other APIs that need it.
It would be same if you created a method yourself and marked one if it's parameters implicit:
object X {
def m(): Unit = {
implicit val myInt = 42
y()
}
def y()(implicit i: Int): Unit = {
println(i)
}
}
Because there is an `implicit` in scope, when invoking `y()` the `myInt` variable will be implicitly passed to the method.
scala> :pa
// Entering paste mode (ctrl-D to finish)
object X {
def m(): Unit = {
implicit val myInt = 42
y()
}
def y()(implicit i: Int): Unit = {
println(i)
}
}
// Exiting paste mode, now interpreting.
defined object X
scala> X.m()
42
Problem
Most of the play framework I see the block of code ``` // Returns a tasks or an 'ItemNotFound' error def info(id: Long) = SecuredApiAction { implicit request => maybeItem(Task.findById(id)) } ``` yes my understanding is define a method `info(id: Long)` and in scala doc to create function in scala the syntax look like this: ``` def functionName ([list of parameters]) : [return type] = { function body return [expr] } ``` Can you tell me what is the meaning of `implicit request =>` and `SecuredApiAction` put before `{`