Java examples no longer work about ping-play HOT 3 CLOSED

Split the sample apps into Java and Scala versions to work around this.

from ping-play.

I'm following your changes and learning a lot. Fantastic work, the code is soo clean.

I might have an idea regarding error handling and the problem that headers are already sent. The header (and footer) itself could also be a Pagelet. If one important service call fails, another responce can be given (404, 301/302). This requires a little bit more waiting time and a combination of "important" Pagelets with fromSequentialPagelets and JavaScript driven fromInterleavedPagelets. This adds waiting time to the first byte, of course.

from ping-play.

@mantsak: Thanks!

I think if there is data that is absolutely critical and you want to wait for it before sending back headers, you would structure the controller code like this:

def index = Action.async {
  val dataFuture1 = makeServiceCall()
  val dataFuture2 = makeServiceCall()
  val criticalDataFuture = makeServiceCall()

  val pagelet1 = Pagelet.fromHtmlFuture(dataFuture1)
  val pagelet2 = Pagelet.fromHtmlFuture(dataFuture2)

  val body = HtmlStream.fromInterleavedPagelets(pagelet1, pagelet2)

  for {
    criticalData <- criticalDataFuture
  } yield {
    Ok.chunked(views.stream.myTemplate(criticalData, body))
  }
}

In other words, data that you must wait for you treat as a normal Future and only send back a response after it has redeemed. The rest of the data, you shove into an HtmlStream (i.e. an Enumerator) and allow it stream down whenever the data comes back, or even if there is an error. In fact, I added an example of how to handle errors while streaming in the sample apps. Check out controllers.MoreBigPipeExamples#errorHandling.

from ping-play.