Howto use lib-noir stateful-sessions in Compojure

问题

I think I have a fairly straightforward problem here. But I've been looking at this screen too long. So I'm trying (and failing) to get stateful sessions working in Compojure. The refheap code paste is here.

You can see me trying to use lib-noir (line 62) to initialize stateful sessions. Then when the app is running, I try to make a call to session/put! some data in the session (line 43).

Now, this stacktrace says that in session.put!, lib-noir is trying to swap out a session var that hasn't been bound. Now, I thought I did that on line 62. So I'm sure this is a simple fix that another set of eyes will see.

java.lang.ClassCastException: clojure.lang.Var$Unbound cannot be cast to clojure.lang.Atom                                                                                                                                                                                                                                                                                                                                
        at clojure.core$swap_BANG_.invoke(core.clj:2110)                                                                                                                                                                                                                                                                                                                                                                  
        at noir.session$put_BANG_.invoke(session.clj:18)                                                                                                                                                                                                                                                                                                                                                                  
        at bkell.http.handler$fn__6159.invoke(handler.clj:156)                                                                                                                                                                                                                                                                                                                                                            
        at compojure.core$make_route$fn__3800.invoke(core.clj:93)                                                                                                                                                                                                                                                                                                                                                         
        at compojure.core$if_route$fn__3784.invoke(core.clj:39)                                                                                                                                                                                                                                                                                                                                                           
        at compojure.core$if_method$fn__3777.invoke(core.clj:24)                                                                                                                                                                                                                                                                                                                                                          
        at compojure.core$routing$fn__3806.invoke(core.clj:106)                                                                                                                                                                                                                                                                                                                                                           
        at clojure.core$some.invoke(core.clj:2390)                                                                                                                                                                                                                                                                                                                                                                        
        at compojure.core$routing.doInvoke(core.clj:106)                                                                                                                                                                                                                                                                                                                                                                  
        at clojure.lang.RestFn.applyTo(RestFn.java:139)                                                                                                                                                                                                                                                                                                                                                                   
        ...
        at java.lang.Thread.run(Thread.java:619)

Thanks

回答1:

Answered by James Reeves at - https://groups.google.com/forum/#!topic/compojure/yG6nCXiEinU

Try swapping around handler/site and wrap-noir-session*. Because handler/site applies the wrap-session middleware, and wrap-noir-session* depends on that according to the documentation, handler/site should be applied before wrap-noir-session.

• James

回答2:

I think you want wrap-noir-session, not wrap-noir-session*. The documentation on wrap-noir-session* says (my emphasis) "A stateful layer around wrap-session. Expects that wrap-session has already been used."

If you want to use wrap-noir-session* I think you'll need to use wrap-session explicitly.

回答3:

Putting down my answer as I keep coming to this question and forgetting it's been solved.

(ns my-project.handler
    (:require (compojure [handler :as handler]
                         [route :as route]
                         [core :refer :all])
              [noir.util.middleware :as middleware]
              [noir.session :as session]))

(defroutes my-routes
  (GET "/put" req (session/put! :test "yes"))
  (GET "/get" req (session/get :test))
  (route/resources "/")
  (route/not-found "Not Found"))

(def app
  (-> 
   (handler/site my-routes)
    session/wrap-noir-flash ; only if you need flash-put! and flash-get
    session/wrap-noir-session))

来源：https://stackoverflow.com/questions/14806063/howto-use-lib-noir-stateful-sessions-in-compojure