Can I do async form validation in Play Framework 2.x (Scala)?

Question

I\'m making a real push to understand the async powers of Play but finding a lot of conflict with regard to places where async invocation fits and places where the framework see

Answer 1

Form validation means syntactic validation of fields, one by one. If a filed does not pass the validation it can be marked (eg. red bar with message).

Authentication should be placed in the body of the action, which may be in an Async block. It should be after the bindFromRequest call, so there must me after the validation, so after each field is not empty, etc.

Based on the result of the async calls (eg. ReactiveMongo calls) the result of the action can be either BadRequest or Ok.

Both with BadRequest and Ok can redisplay the form with error message if the authentication failed. These helpers only specify the HTTP status code of the response, independently to the response body.

It would be an elegant solution to do the Authentication with play.api.mvc.Security.Authenticated (or write a similar, customized action compositor), and use Flash scoped messages. Thus the user always would be redirected to login page if she is not authenticated, but if she submits the login form with wrong credentials the error message would be shown besides the redirect.

Please take a look on the ZenTasks example of your play installation.