play framework - render view while doing processing/redirect after X seconds

Question

note: I am new to play framework

For my Play! project, I require some form of asynchronous programming. Simply, I need to display a view, whilst doing processing in the background, followed by a redirect or a new form being rendered.

This question has been asked with no response. I have had a look on the Play Documentation pages, I didn't find any solution there.

What I have tried:

I attempted to modify the AsynchController that is given with the play starter example. However when navigating to http://localhost/message , the function seemed to act more as a sleep instead of a scheduled task which is set and "forgotten" about, i.e. one can continue on with further coding.

AsynchController snippet: with own modification

public CompletionStage<Result> message() {
        return getFutureMessage(5, TimeUnit.SECONDS).thenApplyAsync(s -> ok(views.html.User.Account.verified.render()), exec);
    }

    private CompletionStage<String> getFutureMessage(long time, TimeUnit timeUnit) {
        CompletableFuture<String> future = new CompletableFuture<>();
        actorSystem.scheduler().scheduleOnce(
            Duration.create(time, timeUnit),
            () -> future.complete("Waiting 5 seconds..."),
            exec
        );
        return future;
    }

route entry

GET     /message                 controllers.AsyncController.message

Purpose:

My aim here was for the message Waiting 5 seconds... to be displayed, followed by a +/- 5s delay. Thereafter it would reach the "future" (is this correct?) whereby it would render a view (or redirect to a controller), in this case the verified page ( for account verified).

Am I on the right track with my original goal, where can I get a good example of something similar?

Answer 1

I have a simple solution, but you have to set up 2 entries in route.

The first entry displays the message "Waiting 5 seconds...", while at the same time it give an AJAX call to the second one. The controller for the second entry does the calculation/sleep for 5 seconds, and returns the desired content, which will be rendered on the first page by Javascript.

In the first webpage you would put something like:

  axios.get(second-url)
      .then(function (response) {
        document.getElementById(someplaceholder).innerHTML=response.data.
      })