uploading a file in a non-blocking manner without using gridFSBodyParser(gridFS) - playframework-2.2

Question

The plugin play-reactivemongo offers an easy way to upload a file:
def upload = Action(gridFSBodyParser(gridFS)) { request =>
val futureFile: Future[ReadFile[BSONValue]] = request.body.files.head.ref
futureFile.map { file =>
// do something
Ok
}.recover { case e: Throwable => InternalServerError(e.getMessage) }
}
Unfortunately this solution doesn't suit me because:
I would like only my DAO layer to depend on reactive-mongo.
I need to save the file only if a user is authenticated (with SecureSocial) and use some user's properties as checks and metadata.
If no user is authenticated the request body shouldn't be parsed at all (see also this question).
It would be something along the lines
def upload = SecuredAction { request =>
val user = request.user
val enumerator = an enumrator from the body parsing ???
myDAO.saveFile(user, enumerator)
object myDAO {
def saveFile(user:User, enumerator:Enumerator[Array[Byte]]) = {
...
val fileToSave = DefaultFileToSave(...)
gridfs.save(enumerator, fileToSave)
...
}
}
Unfortunately it seems there is no way to get an enumerator from the parsing of the request body. The only way seems to provide the Action with a parser and an Iteratee that will be fed with the the body being parsed.
I couldn't figure out how to achieve it in a reactive way (without using a temporary file or storing the body in memory). Is it at all possible?

Answer 1

Actually, you might consider not using girdFS built-in parser at all:
val gfs = new GridFS(db)
// the controller method, Authenticated here is custom object extending ActionBuilder
def upload = Authenticated.async(parse.multipartFormData) { request =>
...
request.body.file("photo") match {
// handle error cases
...
case Some(photo) =>
val fileToSave = DefaultFileToSave(photo.filename, photo.contentType)
// here some more operations, basically you don't need the and need only photo.ref.file
val enumerator = Enumerator(Image(photo.ref.file).fitToWidth(120).write)
gfs.save(enumerator, fileToSave) map {
//handle responses and stuff
...
}
}
}
}