Clojurians Log v2

hey all! i'm trying out integrant in my app and it's going well enough, but i have a question that's not answered by the docs: i want access to the object created by integrant/`init-key` so i can reference it in the rest of my app. is that possible?

if not, should I bind the result to an atom and then (reset! state nil) in halt-key! ?

oh, this is the returned object from init, not init-keys. nevermind, i have figured it out

actually, follow up. my current app has a function connect which connects to the running mongo instance using an aero config file, and then uses defonce to create a db var with the returned mongo db connection

and then in the meat of the app, that db var is required and used, which assumes that the connection has been made and the var has been defined, etc

I'd avoid using defonce with integrant

or to be broader, I'd avoid global defs for state with integrant

what is the more functional approach to write something like that?

just return the state from an init-key

and it'll be in the system map

and if your other component needs it, #ref that in the config

i'm sorry, i meant in a function like

(defn superusers []
  (mc/find-maps db "users" {$or [{:isadmin true}
                                 {:ismoderator true}
                                 {:tournament-organizer true}]}))

the current codebase is filled with functions like this, that assume the connection exists in the db var

is it better to pass the integrant system into all of these calls? or to assign it to a global variable and require it?

If you need a quick first pass, I'd go with the former out of those two

but you could make that fn a component itself sort of how handler/greet returns a function at https://github.com/weavejester/integrant#initializing-and-halting

that page doesn't load for me

apologies, wrong link

or you could make a component that returns a reify over a protocol, wrapping your db and exposing all the db-needing functions

hmmmm interesting!

or some groupings of functions in between one-fn-per-component and all-db-fns-in-one

that's suitable to your usecases

yeah makes sense

i'll have to think about this a bunch, see what makes most sense

the point of integrant is that you build up components that are self-contained enough so that other, dependent components only need to pass in args that are relevant to their usecases

You can eliminate most if not all global state this way as all of it will be inside the system map.

yeah, that's definitely the goal cuz it's a ball of spaghetti right now

hah, I've learned that not even integrant can guarantee spaghettilessness 😄

23 different namespaces require that db var, which makes it "easy" but also very messy and means we have to be careful when writing tests or running things individually

you can have one component per namespace for example

each returning something that wraps its functions, requiring the db component

that's a neat trick. i realize i'm asking a lot, but do you have any projects/examples of that kind of logic?

I'm afraid I don't have anything I'd be allowed to share. But integrant is a phrase specific enough that a github code search should give you some examples

coolio, thanks so much for the help

Nb, good luck! It takes a little getting used to but it's worth it