Question

Our website was recently rewritten in the Play framework. We offer file downloads to users, and files download correctly using renderBinary().

Now I’d like to display/render a new html page to the user while the binary file downloads in the background. Sort of like this:

[Dear website user: Click here to download this file: bigfile.zip]

After the user clicks, bigfile.zip begins downloading. Then I want to show user a new page:

[Dear website user: Thanks for downloading bigfile. Here is some additional information.]

Calls to renderBinary() never return, so I can’t call something like Application.showMyPage() afterwards. Similarly, a call to render my html page [Application.showMyPage()] never returns either, so I can’t call renderBinary() after.

Maybe a javascript onclick is the only way to do it, but I’d love to know if there’s a clean way to do it in Play.

Answer 1

What you are asking is for your client side to perform two simultaneous requests, which isn’t how HTTP works. The easiest way, and the way that I see download sites work, is as follows

1. Display page with click here to download link
2. On click of the download link, display your thank-you page, which has a piece of javascript to automatically start the download of the file, by calling your action with the renderBinary method.

It is a user experience that people are generally expecting.