Applying middleware to selected routes

gistfile1.clj

(ns composable-compojure.handler
  (:use compojure.core)
  (:require [compojure.handler :as handler]
            [ring.util.response :refer [response]]))

(defn middleware
  [handler value]
  (fn [request]
    (handler (update-in request [:from-middleware] (partial cons value)))))

(defn respond [request] (response (str ":from-middleware = " (:from-middleware request))))
`
(def foo-routes
  (context
   "/foo" []
   (-> (routes
        (GET "/" request (respond request)))
       (middleware "foo"))))

(def bar-routes
  (context
   "/bar" []
   (-> (routes
        (GET "/" request (respond request)))
       (middleware "bar"))))

(def handler
  (handler/site
   (routes foo-routes
           bar-routes)))