Use of undeclared var from a namespace, but the var exists

Question

I have this def in myapp.core (core.cljs):

(def router 
    (reitit/router [["/" {:name :foo :view #'foo}]])
)

And in myapp.events (events.cljs), I use it like so:

{:dispatch [:common/navigate (reitit/match-by-path myapp.core/router "/browse")]}

But I get the error:

{:dispatch [:common/navigate (reitit/match-by-path myapp.core/router "/browse")]
--------------------------------------------------------------------^-----------
 Use of undeclared Var myapp.core/router
--------------------------------------------------------------------------------
1385 |            }

Why would that be?

Answer 1

Since you are using the full name myapp.core/router I assume you don't have a proper require for that namespace in your ns form.

You must have (:require [myapp.core]) in that ns, preferably with an :as alias and using that. It is not allowed to "cheat" by using the full name.