Question

I’m trying to convert a user ID from a User class and store it in a Play! session variable. However when I try to print out that session variable, it returns a blank string. This is a simple authentication.

During authentication:

session += "userid" -> user.id.toString

Printing session variable in Play! scala view:

@ctx("userid")

The whole authentication def:

    def authenticate(login:LoginAttempt) = {
          println("in authenticate")
      User.authenticate(login.username, login.password) match {
            case Some(user:User) => {
              session += "username" -> user.emailAddress
              session += "userid" -> user.id.toString
              session += "name" -> user.name
          session += "accounts" -> user.accounts.toString
              Redirect(session("path").getOrElse("/"))
            }
            case _ => {
              flash += "error" -> "Wrong username or password."
              Action(Authentication.login)
            }
        }
    }

And the User class:

case class User(
  val id: Long,

A solution? What’s missing or going wrong here that’s preventing user.id from being stored in the session? Thanks

Answer 1

After asking around and doing some more reading, this was indeed caused by a “feature” of the Play! 1.2.4 framework. Luckily we can expect more with v2.

For our particular app, there’s a 3rd often overlooked step when it comes to session variables. You need to renderArgs for each one for them to be accessible. So a comment by @ChrisJamesC was mostly right: there was a step missing in initialization.

Here’s what’s going on in our Secure.scala controller:

(session("userid"), session("username"), session("name"), session("accounts")) match {
            case (Some(userid), Some(username), Some(name), Some(accounts)) => {
                renderArgs += "userid" -> userid
                renderArgs += "username" -> username
                renderArgs += "name" -> name
                        renderArgs += "accounts"  -> accounts
                Continue
            }
            case _ => {
                session += "path" -> Request.current().path
                Action(Authentication.login)
            }
        }

In my own case, I didn’t realize that I needed to renderArgs for every variable I want to store and access in a session. But there’s a catch: you still need to store each var as a String.

Then in each Play! view I can access the var like so: @ctx("userid")

I hope this helps future people who are using Play!