I have the following use-case. I implemented a very simple authentication in my play app which adds a session cookie if a user logs in (See code below).
This code works fine so far. What I want to achieve now is to check in my main template if a user is logged in or not and display login/logout elements on the page according to the user status.
How can I achieve this in the most elegant way?
I have found sources where people access the session variables directly from the template with play <= 2.1. It seems like this method doesn't work for 2.2 anymore and is deprecated?
Do I have to pass a boolean value in every action to the template to define if a user is logged in??
Wrapper Action
case class Authenticated[A](action: Action[A]) extends Action[A] {
def apply(request: Request[A]): Future[SimpleResult] = {
if (request.session.get("user").getOrElse("").equals("user")) {
action(request)
} else {
Future.successful(Redirect("/login").withSession(("returnUrl", request.path)))
}
}
lazy val parser = action.parser
}
Submit Part of Login Controller
def submit = Action { implicit request =>
loginForm.bindFromRequest.fold(
errors => Ok(html.login.form(errors)),
requestUser => {
val user: String = Play.current.configuration.getString("fillable.user").getOrElse("")
val password: String = Play.current.configuration.getString("fillable.password").getOrElse("")
if (requestUser.name.equals(user) && requestUser.pw.equals(password))
Redirect(request.session.get("returnUrl").getOrElse("/")).withSession(session + ("user" -> requestUser.name) - "returnUrl")
else
Ok(html.login.form(loginForm, "error", Messages("error.wrongCredentials")))
})
}
Example Controller Action where Authentication is needed
def submit = Authenticated {
Action.async { implicit request =>
...
}
}
So what I found out now is that if the Controller Action uses an implicit request(like the one in my question above) I can use that request and therefore the session in my template if I add this to the head of the template:
(implicit request: Request[Any])
I am not sure if this is a good approach so I am happy if someone can approve it.
Related
So I am working on a webapp in Scala with Play 2.3 using IntelliJ 14.1.1.
The problem is with storing values in the session. I currently have this:
def authCredentials = Action { implicit request =>
loginForm.bindFromRequest.fold(
formWithErrors => BadRequest(views.html.login(formWithErrors.withError("badlogin","Username or password is incorrect."))),
goodForm => Redirect(routes.AccountController.display).withSession(request.session + ("username" -> goodForm._1))
)
}
and then in my AccountController:
def display = Action { implicit request =>
request.session.get("username").map { username =>
Ok(views.html.account(User.getUser(username))).withSession(request.session + ("username" -> username))
}.getOrElse(Redirect(routes.LoginController.login)).withNewSession
}
Now in the the above function it is finding the username and rendering the account page only once. The problem is after that when I want to navigate to a page from the account page such as to the change password page or even a refresh of the account page it will redirect back to login with new session.
What am I doing wrong and is there a better way to check if the session is authenticated for access to the page instead of repeat code on each display function.
It seems to be a simple parentheses problem, try :
def display = Action { implicit request =>
request.session.get("username").map { username =>
Ok(views.html.account(User.getUser(username))).withSession(request.session + ("username" -> username))
}.getOrElse(Redirect(routes.LoginController.login).withNewSession)
}
You were in fact resetting the session in any case in your controller, now the withNewSession call is inside getOrElse, which send a new session only in case of no username found in the current one.
I've written an API based on Play with Scala and I'm quite happy with the results. I'm in a stage where I'm looking at optimising and refactoring the code for the next version of the API and I had a few questions, the most pressing of which is authentication and the way I manage authentication.
The product I've written deals with businesses, so exposing Username + Password with each request, or maintaining sessions on the server side weren't the best options. So here's how authentication works for my application:
User authenticates with username/password.
Server returns a token associated with the user (stored as a column in the user table)
Each request made to the server from that point must contain a token.
Token is changed when a user logs out, and also periodically.
Now, my implementation of this is quite straightforward – I have several forms for all the API endpoints, each one of which expects a token against which it looks up the user and then evaluates if the user is allowed to make the change in the request, or get the data. So each of the forms in the authenticated realm are forms that need a token, and then several other parameters depending on the API endpoint.
What this causes is repetition. Each one of the forms that I'm using has to have a verification part based on the token. And its obviously not the briefest way to go about it. I keep needing to replicate the same kind of code over and over again.
I've been reading up about Play filters and have a few questions:
Is token based authentication using Play filters a good idea?
Can a filter not be applied for a certain request path?
If I look up a user based on the supplied token in a filter, can the looked up user object be passed on to the action so that we don't end up repeating the lookup for that request? (see example of how I'm approaching this situation.)
case class ItemDelete(usrToken: String, id: Long) {
var usr: User = null
var item: Item = null
}
val itemDeleteForm = Form(
mapping(
"token" -> nonEmptyText,
"id" -> longNumber
) (ItemDelete.apply)(ItemDelete.unapply)
verifying("unauthorized",
del => {
del.usr = User.authenticateByToken(del.usrToken)
del.usr match {
case null => false
case _ => true
}
}
)
verifying("no such item",
del => {
if (del.usr == null) false
Item.find.where
.eq("id", del.id)
.eq("companyId", del.usr.companyId) // reusing the 'usr' object, avoiding multiple db lookups
.findList.toList match {
case Nil => false
case List(item, _*) => {
del.item = item
true
}
}
}
)
)
Take a look at Action Composition, it allows you to inspect and transform a request on an action. If you use a Play Filter then it will be run on EVERY request made.
For example you can make a TokenAction which inspects the request and if a token has been found then refine the request to include the information based on the token, for example the user. And if no token has been found then return another result, like Unauthorized, Redirect or Forbidden.
I made a SessionRequest which has a user property with the optionally logged in user, it first looks up an existing session from the database and then takes the attached user and passes it to the request
A filter (WithUser) will then intercept the SessionRequest, if no user is available then redirect the user to the login page
// Request which optionally has a user
class SessionRequest[A](val user: Option[User], request: Request[A]) extends WrappedRequest[A](request)
object SessionAction extends ActionBuilder[SessionRequest] with ActionTransformer[Request, SessionRequest] {
def transform[A](request: Request[A]): Future[SessionRequest[A]] = Future.successful {
val optionalJsonRequest: Option[Request[AnyContent]] = request match {
case r: Request[AnyContent] => Some(r)
case _ => None
}
val result = {
// Check if token is in JSON request
for {
jsonRequest <- optionalJsonRequest
json <- jsonRequest.body.asJson
sessionToken <- (json \ "auth" \ "session").asOpt[String]
session <- SessionRepository.findByToken(sessionToken)
} yield session
} orElse {
// Else check if the token is in a cookie
for {
cookie <- request.cookies.get("sessionid")
sessionToken = cookie.value
session <- SessionRepository.findByToken(sessionToken)
} yield session
} orElse {
// Else check if its added in the header
for {
header <- request.headers.get("sessionid")
session <- SessionRepository.findByToken(header)
} yield session
}
result.map(x => new SessionRequest(x.user, request)).getOrElse(new SessionRequest(None, request))
}
}
// Redirect the request if there is no user attached to the request
object WithUser extends ActionFilter[SessionRequest] {
def filter[A](request: SessionRequest[A]): Future[Option[Result]] = Future.successful {
request.user.map(x => None).getOrElse(Some(Redirect("http://website/loginpage")))
}
}
You can then use it on a action
def index = (SessionAction andThen WithUser) { request =>
val user = request.user
Ok("Hello " + user.name)
}
I hope this will give you an idea on how to use Action Composition
The people at Stormpath has a sample Play application providing authentication via their Backend Service. Some of its code could be useful to you.
It uses username/password rather than tokens, but it should not be complex to modify that.
They have followed this Play Document:
https://www.playframework.com/documentation/2.0.8/ScalaSecurity.
The specific implementation for this is here:
https://github.com/stormpath/stormpath-play-sample/blob/dev/app/controllers/MainController.scala.
This Controller handles authentication operations and provides the isAuthenticated action via the Secured Trait (relying on play.api.mvc.Security). This operation checks if the user is
authenticated and redirects him to the login screen if he is not:
/**
* Action for authenticated users.
*/
def IsAuthenticated(f: => String => Request[AnyContent] => Future[SimpleResult]) =
Security.Authenticated(email, onUnauthorized) { user =>
Action.async { request =>
email(request).map { login =>
f(login)(request)
}.getOrElse(Future.successful(onUnauthorized(request)))
}
}
Then, each controller that needs authenticated operations must use the
Secured Trait:
object MyController extends Controller with Secured
And those operations are "wrapped" with the IsAuthenticated action:
def deleteItem(key: String) = IsAuthenticated { username => implicit request =>
val future = Future {
MyModel.deleteItem(request.session.get("id").get, key)
Ok
}
future.map(
status => status
)
}
Note that the deleteItem operation does not need a username, only the key. However, the authentication information is automatically obtained from the session. So, the business' API does not get polluted with security-specific parameters.
BTW, that application seems to have never been officially released so consider this code a proof of concept.
Few days ago I run into an eventually missing feature of Play, that is Action Chaining. Here's what I mean:
I have a controller with two Actions, and I'd like to call an action from another action in order to stay DRY. My goal is to automatically sign a user in after he signs on.
object MyController extends Controller {
def signOn = Action {
// ... do stuff to sign the user on
signIn // call the next Action
}
def signIn = Action {
// ... do stuff to sign the user in
Ok("Welcome, Dude!")
}
}
I've found this nice but outdated solution here (it's for Play 2.0.x)
http://www.natalinobusa.com/2012/07/chained-actions-in-play-framework-20.html
now I'm trying to write something similar on Play 2.2.x but I'd like to know if it is actually a missing feature and if some of you has already implemented something similar.
And finally: would you think it would be something nice to have in the framework?
What about doing it like this?
def signOn = Action.async { request =>
// ... do stuff to sign the user on
signIn(request) // call the next Action
}
def signIn = Action {
// ... do stuff to sign the user in
Ok("Welcome, Dude!")
}
The solution proposed by Johan is what I was looking for. I ended up with this (nice?) solution for a neat chained action controller
package controllers
import play.api._
import play.api.mvc._
object TestCtrl extends Controller {
def signOn = Action.async { request =>
// ... do stuff to sign the user on
if ( true )
signIn(request) // call the next Action
else
stopChaining( Ok("Stop") )(request)
}
def signIn = Action {
// ... do stuff to sign the user in
Ok("Welcome, Dude!")
}
private def stopChaining(result: SimpleResult) = Action {
// ... do nothing, just return the result
result
}
}
I'm trying to use action composition to add a fake user to Session.
def GuestAction(f: Request[AnyContent] => Result): Action[AnyContent] = {
Action { request =>
var myUser = searchUser(request.session)
if ( myUser == null ) {
myUser = newUser()
}
f(request).withSession("user" -> myUser)
}
}
In my controller there is
def action1 = GuestAction { implicit request =>
// My code
Ok()
}
def action2 = GuestAction { implicit request =>
val user = request.session.get("user").get
// My code
Ok()
}
When I open Chrome and browse to the route pointing to "action1" and then to the route pointing to "action2", everything works fine: I got a new user and it is attached to the session.
On the contrary, when I open Chrome and I browse to the route pointing to "action2" first, I got an error because my "request.session" is empty, and that's obvious: using .withSession() the session is attached to the Result, not to the incoming request.
So, in order to make this work, I need to attach the session key/value pairs to the incoming request - like it is possible in FakeRequest.withSession(), but there's no such method in Request.
What would you suggest in order to fix this issue?
You're very nearly there - but to get the maximum value from your Action composition, you should be able to make your "client" Actions totally unaware of the session - they really only care about the User object after all. You want to be able to write:
def action2 = GuestAction { implicit user => implicit request =>
// Do something with 'user', whether it's a guest or real
println(s"My user is $user")
Ok()
}
action2 doesn't care how the User was obtained, but it can rely on one being available. To make this happen, GuestAction needs to be something like this:
def GuestAction(f: (User) => Request[AnyContent] => Result): Action[AnyContent] = {
Action { request =>
var myUser = searchUser(request.session)
if ( myUser == null ) {
myUser = newUser()
}
f(myUser)(request)
}
}
The only remaining piece of the puzzle is putting a user into the session - which you can still do with a conventional response.withSession() as part of a successful login process.
I will use slightly modified Listing 4.7 from the book Exploring Lift to ask my question.
// In Boot.boot:
LiftRules.viewDispatch.append {
case List("Expenses", "recent", acctId, authToken) =>
Left(() => Full(RSSView.recent(acctId, authToken)))
// This is a dispatch via the same LiftView object. The path
// "/Site/news" will match this dispatch because of our dispatch
// method defined in RSSView. The path "/Site/stuff/news" will not
// match because the dispatch will be attempted on List("Site","stuff")
case List("Site") => Right(RSSView)
}
// Define the View object:
object RSSView extends LiftView {
def dispatch = {
case "news" => siteNews
}
def recent(acctId : String, authToken : String)() : NodeSeq = {
// User auth, account retrieval here
...
<lift:surround with="rss" at="content">
<lift:Vote.image />
</lift:surround>
}
// Display a general RSS feed for the entire site
def siteNews() : NodeSeq = { ... }
}
How do I pass acctId from the view function recent into the snippet lift:Vote.image? Thanks.
If you're attempting to get the acctId and authToekn from boot for a user, this won't work. Boot only runs when the web application starts up, not once for every user.
You'll have to set SessionVar's when the user logs in, or when you detect the autologin cookie, and then access the sessionVar where you need it.