no

reg-sub are fired when the db changes

it happens in a cascade, because first those that depend directly on db, and then those that depend on those reg-sub that have recalculated

re-frame creates a graph of interdependent reagent atoms

You mean when the arguments to different rf/subscribe calls are the same, right?

Sorry, to multiple rf/subscribe calls to the same subscription. For example:

(for [x (range 10)]
  [:span (<sub [:foo])])

I don’t remember if sometime I read that this does not create multiple reactions (low level). I’m thinking on performance.

Indeed, corresponding reactions are cached, so in that case only one reaction is created.

From the docstring of subscribe:

**De-duplication**

  Two, or more, concurrent subscriptions for the same query will
  source reactive updates from the one executing handler.

Although I guess the wording is quite opaque when you don't know that the cache exists. :) In any case, the implementation of the caching is also rather straightforward.

I remember that was explained in one of the md docs, but maybe I did read it from there. Thanks

This is the closest related one that I know of: https://github.com/day8/re-frame/blob/master/docs/FAQs/Why-Clear-Sub-Cache.md

It was from that document 😃

Maybe this will help, although I haven't used it myself: https://github.com/ingesolvoll/re-chain

Thanks!

If we abstract away the specifics, all that's left is the need to handle an async operation. With that being said, coeffects don't support anything async, but effects do. So what you can do is create an effect for reading files and pass something like :on-read to it which would be an event fired by that effect with the file's contents once the reading is done.

Just use something like

(ns a.b
  (:require [re-frame.core :as rf]))

(defn ^:export dispatch [event]
  (rf/dispatch event))

perfect.. was going down this road, this might just work :face_vomiting:

I think controllers is the common way to initialize some specific data of a route. There is an example on reitit repo: https://github.com/metosin/reitit/tree/master/examples/frontend-re-frame You could also initialize data on main (`init!`) using dispatch-sync (maybe also using https://github.com/day8/re-frame-async-flow-fx) but that is application data. It depends of what you need.

Okay, I'm interested in lazy loading only the necessary data for each route (sub application) since the app is quite data heavy. But if it is idiomatic to use re-frames dispatch within the controllers that's probably okay. I'm only afraid that it will crash with other events, but since re-frame uses an event queue it will probably be okay(?).