ring-compojure-flash.clj

(ns example.flash
  (:use compojure.core)
  (:use ring.util.response)
  (:use ring.middleware.session)
  (:use ring.middleware.flash)
  (:require [compojure.route :as route]))

(defn show-new [flash]
  (str "Flash: " flash
    "<br/>
     <form method='POST' action='/news'>
       <input type='submit' value='Success'>
     </form>
     <form method='POST' action='/newf'>
       <input type='submit' value='Error'>
     </form>"))

(def flash-success {:flash {:success "Success"}})
(def flash-error   {:flash {:error   "Failed"}})

(defroutes handler
  (GET  "/" [] "<h1>Hello World Wide Web!</h1>")
  (GET  "/new"  {flash :flash}   (show-new flash))
  (POST "/news" {params :params} (merge (redirect "/new") flash-success))
  (POST "/newf" {params :params} (merge (redirect "/new") flash-error))
  (route/not-found "Page not found"))

(def app (wrap-session (wrap-flash handler)))

(defonce x (future (run-jetty (var app) {:port 8088})))