ring.middleware.flash

(source)
Middleware that adds session-based flash store that persists only to the next request in the same session.

For more info about this library see:

https://github.com/ring-clojure/ring/wiki
Public Variable Short Description
flash-request (clj) Adds :flash key to request from :_flash in session.
flash-response (clj) If response has a :flash key, saves it in :_flash of session for next request.
wrap-flash (clj) If a :flash key is set on the response by the handler, a :flash key with the same value will be set on the next request that shares the same session.