I think what you actually want is:
(defn get-id []
(session/get :uid))
in your code, you're trying to call #'session/get directly and bind it
to get-id. Of course, the problem with this is that #'session/get
expects to be called in the context of a request which is where your
Unbound var exception is coming from.
Hope this helps,
Dave
On Mon, Apr 30, 2012 at 11:39 AM, Travis Smith <tra...@legomaster.net> wrote:
> What does 'java.lang.ClassCastException: clojure.lang.Var$Unbound cannot be
> cast to clojure.lang.IDeref' mean. I'm getting this a lot and I want to
> understand it better, make it easier for me to avoid this. Most of the time
> I just end up adjusting my def/defn's around until it works. This is hardly
> optimal.
>
> (this is all on clojure 1.3.0)
>
> An example...
>
> (ns app-admin.models.current-user
> (:require [noir.session :as session]
> [app-admin.models.users :as users]))
>
> (def get-id
> (session/get :uid))
>
> (defn set-user! [user]
> (session/put! :uid {:_id user}))
>
> Give me an exception for get-id
>
> ClassCastException clojure.lang.Var$Unbound cannot be cast to
> clojure.lang.IDeref clojure.core/deref (core.clj:2078)
>
> So set-user! binds correctly, but get-id doesn't seem to...
>
> => (get-id)
> llegalStateException Attempting to call unbound fn:
> #'app-admin.models.current-user/get-id clojure.lang.Var$Unbound.throwArity
> (Var.java:43)
>
> Then I check it...
>
> => (meta #'get-id)
> {:ns #<Namespace app-admin.models.current-user>, :name get-id}
>
> So it's there, the fn is bound; I'm not exactly sure what's going on and nor
> what I'm missing about how this works to help me avoid problems like this in
> future. Just guessing and tweaking has gotten me so far, but that's not
> sustainable.
>
> Thanks!
>
> -Travis
>
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