example_web_app.clj

(ns example.web-app
  (:use compojure.core))

;; Simple storage mechanism

(def *shorturls* (ref {}))
(defn put-url [key url]
     (dosync (alter *shorturls* assoc key url)))
(defn get-url [key]
     (get @*shorturls* key))
(defn url-exists? [key]
     (contains? @*shorturls* key))

(defn handle-put-req [name newurl]
  (let [code (if (url-exists? name) 204 201)]
    (put-url name newurl)
    {:status code}))
    
(defroutes bookmark-app
  (GET "/" []  "Send me your bookmarks.")
  (GET "/:name" [name] (if (url-exists? name)
                         {:status 301 :headers {"Location" (get-url name)}}
                         {:status 404 :body "No such bookmark."}))
  (PUT "/:name" [name newurl] (if (and name newurl)
                                (handle-put-req name newurl)
                                {:status 400 :body "No \"newurl\" parameter provided!"})))