Simple Ring Demo with Routing

ring-with-routing.core.clj

(ns ring-with-routing.core
  (require
    [ring.adapter.jetty :refer [run-jetty]]
    [ring-with-routing.handler :as h]
    [ring-with-routing.middleware :as m]
    ))

(def app
  (-> h/handler-with-routing
      m/logger
      m/req-res-displayer
      m/wrap-params))

(defonce server 
  (run-jetty #'app {:port 8080 :join? false}))

ring-with-routing.handler.clj

(ns ring-with-routing.handler
  (require
    [ring.util.response :as res]
    ))

(defn main [req]
  (-> (res/response 
       "<div>
          <h1>Hello Web Page with Routing!</h1>
          <p>What would you like to do?</p>
          <p><a href='./get-form.html'>Submit a GET request</a></p>
          <p><a href='./post-form.html'>Submit a POST request</a></p>
        </div>")
      (res/content-type "text/html")))

(defn get-form [req]
  (-> (res/response 
       "<div>
          <h1>Hello GET Form!</h1>
          <p>Submit a message with GET</p>
          <form method=\"get\" action=\"get-submit\">
           <input type=\"text\" name=\"name\" />
           <input type=\"submit\" value\"submit\" />
          </form>
          <p><a href='..'>Return to main page</p>
        </div>")
      (res/content-type "text/html")))

(defn post-form [req]
  (-> (res/response 
       "<div>
          <h1>Hello POST Form!</h1>
          <p>Submit a message with POST</p>
          <form method=\"post\" action=\"post-submit\">
           <input type=\"text\" name=\"name\" />
           <input type=\"submit\" value\"submit\" />
          </form>
          <p><a href='..'>Return to main page</p>
        </div>")
      (res/content-type "text/html")))

(defn display-result [req]
  (let [{:keys [params uri]} req
        param-name (get params "name")
        req-type (if (= uri "/get-submit") "GET" "POST")]
    (-> (res/response 
          (str
           "<div>
              <h1>Hello " param-name "!</h1>
              <p>Submitted via a " req-type " request.</p>
              <p><a href='..'>Return to main page</p>
            </div>"))
      (res/content-type "text/html"))))

(defn not-found [req]
  (-> (res/not-found "<h1>404 Error!</h1>
                      <b>Page not found!</b>
                      <p><a href='..'>Return to main page</p>")
      (res/content-type "text/html")))


(defn handler-with-routing [req]
  (println "In Routing Handler!")
  (let [{:keys [uri params request-method]} req]
    (cond
      (= uri "/") (main req)
      (= uri "/get-form.html") (get-form req)
      (= uri "/post-form.html") (post-form req)
      (= uri "/get-submit") (display-result req)
      (= uri "/post-submit") (display-result req)
      :else (not-found req))))

ring-with-routing.middleware.clj

(ns ring-with-routing.middleware
  (require
    [ring.middleware.params :as mparams]
    ))

(defonce log-atom (atom []))
(defn logger [handler]
  (fn [req]
    (let [res (handler req)]
      (swap! log-atom #(conj % {:request req :response res}))
      res)))

(defn req-res-displayer [handler]
  (fn [req]
    (let [res (handler req)]
      (println "\nRequest:")
      (clojure.pprint/pprint req)
      (println "\nResponse:")
      (clojure.pprint/pprint res)
      res)))

(def wrap-params 
  mparams/wrap-params)

ring-with-routing.project.clj

(defproject ring-with-routing "0.1.0-SNAPSHOT"
  :dependencies [[org.clojure/clojure "1.7.0"]
                 [ring "1.5.0"]])