Question

Play’s flash is a “temporary storage mechanism that is kept for the duration of the next request”, using cookies.

Is it possible to read the flash from javascript?

I want to implement a generic client-side notification mechanism, and also access that mechanism from the server. What I imagine is for any controller to do:

flash.put("notification", "You have been notified");

And then for my main.js to check if the “notification” flash exists, and if it does display it above (similar to Stack Overflow’s notification mechanism).

However, I suspect that flash might be encrypted in a way that the client side cannot read it. I haven’t found any code samples that show how to read it from the client side JS (not in a template). Is this possible directly?

As I’m writing this question, I’m actually coming up with a way to implement this: I can put a hidden div in the main template that all my views extend, and access that div from JS. Does it make sense? Is there a simpler approach?

Answer 1

I don’t think it’s possible to use JavaScript to read flash, even via the cookie. That cookie is actually encrypted with a security seeds (application.secret) configured in your application.conf.

However it is possible to implement what you want.

1. Create a tag to export flash variables into Javascript object.
2. Call that tag in your view.
3. Your main.js use that exposed variable to do whatever it want.