Clojurians Log v2

You know in the example, on the github project page, it has (defmethod ig/init-key :adapter/jetty [_ {:keys [handler] :as opts}] and (defmethod ig/init-key :handler/greet [_ {:keys [name]}]

I can see where the keys part works, but why the don't care placeholder, i.e., _

What would go there?

You could just print it out

Yeah, good idea.

it's the key name

or rather, the multimethod dispatch value

so, in the example above (first one), if _ is replaced with foo and then a (println foo), the output will be :adapter/jetty

IIRC it will be the argument the method is called with

Or rather the arguments

(defmulti ex (fn[x y] (:a x)))
(defmethod ex 2 [x y] (prn 2 x y))
(ex {:a 2 :b 3} {:d 123})
=> 2 {:a 2, :b 3} {:d 123}

ta 🙂

Quite new to this, but if I wanted to share the integrant initialised "system" (by calling (ig/init! config)) an approach would be to store that system in an atom (say my core namespace) then refer to that atom in each of my other namespaces to then obtain the values required (in the other namespace?)

I think the purpose of integrant is to make untangling and encapsulation of a system easier. I think if you need to get something from running system then you, probably, should think twice. But if you really need, you could peek into https://github.com/weavejester/integrant-repl/blob/89a9552fd3623976b83318a5f8f903f1ebeda2f7/src/integrant/repl.clj#L47

Thank you. I'll have a ponder 🙂