How to handle multiple async requests for a Mustache template on Scalatra

Question

I have a simple web app running on Scalatra with Mustache templates. In order to render the page, I need to make three separate requests to web services. Is the Akka approach shown in Scalatra guides the way to go? Do I need to introduce chaining or latches? Or is it possible to pass results to Mustache template as they arrive?

Answer 1

You want to call the render method (mustache()) when your future completes. So something along these lines:

makeAsyncCall() map (result => mustache("template.mustache", "result" -> result))

Answer 2

This is what I ended up using.

new AsyncResult {

  val animals = for{
    r1 <- service.getCats()
    r2 <- service.getDogs()
    r3 <- service.getPonies()
  } yield (r1, r2, r3)

  val is = animals map (result => mustache("/template.mustache", "cats" -> result._1, "dogs" -> result._2, "ponies" -> result._3))
}