gistfile1.clj

;; The middleware takes 'app' as its parameter.  In this 
;; context app is going to be either another middleware 
;; or the route handler.
;; 
;; The return value is a new function that does the 
;; processing you need and continues the middleware 
;; chain.
(defn my-middleware [app]
  (fn [request] 
     ;; This is where you'd do any processing on the request
     ;; Finally, keep the chain going by calling app
     (app request)))