Issue in using nativestore with Om

[viksit]

Are there any examples of using this with Om?

(solved, original issue)

I'm trying to use native store like the following,

(ns my-ns
  (:require  [nativestore.core :as store])))

(let [store2 (store/create)
      a 1]
  (do
    (store/insert! store2 #js {:id 1 :firstname "Joe" :lastname "Smith"})
    (prn "a: " 1)
    (prn "store2: " store2 "id: " (get store2 id))
    (prn (type #js {:id 1 :fname "abc"}))
    (prn (type {:id 1 :fname "def"}))))

and I get

"a: " 1 
"store2: " #NativeStore[] "id: " nil
#<function Object() { [native code] }>
cljs.core/PersistentArrayMap

What am I doing wrong here? Is this a bug?

I've git cloned this repo, and added the following deps to my project.clj,

[im.chit/purnam.native "0.4.3"] [prismatic/schema "0.2.6"] [com.vitalreactor/derive "0.2.0-SNAPSHOT"]

Thanks!

[viksit]

Alright, I think I've figured this out for basics.

(def store1 (store/create))
(def idx1 (store/ordered-index (store/field-key :lastname) compare))
(store/ensure-index store1 :lastname idx1)

(store/insert! store1 #js {:id 1 :firstname "Joe" :lastname "Smith"})
(store/insert! store1 #js {:id 2 :firstname "Fred" :lastname "Savage"})
(store/insert! store1 #js {:id 3 :firstname "Larry" :lastname "Stooge"})
(store/insert! store1 #js {:id 4 :firstname "Curly" :lastname "Stooge"})
(store/insert! store1 #js {:id 5 :firstname "Mo" :lastname "Stooge"})
(store/insert! store1 #js {:id 6 :firstname "Reginald" :lastname "Quince"})

;; (store/cursor store1)
;; (println store1)
(println (get store1 1))

[eslick]

Looked like there was a bug in the first message, but I'm glad to see you've got it. NativeStore is a pretty sophisticated tool, not many seatbelts. Playing with the SimpleStore implementation in Derive to learn the model and try it out with React is probably the preferred approach for now.

[viksit]

Thanks @eslick - derive itself looks quite datalog like, with a pretty sophisticated query model (from what I could see here: https://github.com/vitalreactor/derive/blob/master/src/derive/examples.temp

I looked at https://github.com/vitalreactor/derive/blob/master/src/derive/simple.cljs already, and I can see utilizing it using Om.

Two questions here would be,

• Could you give an example of using cursors in nativestore? You only use ->> in the examples page and I haven't yet been able to get cursors to work with a very simple example.
• For simplestore, is there an example of how I would specify a path to om/root?

Thanks!

[eslick]

A cursor returns an object that implements IReducable. I did this on purpose so we wouldn't get lazy and constantly be turning it into a seq, but maybe I should add that for easy use at the Repl. Try:

(map :firstname (store/cursor store1))  

This should reduce using sequence operations over the cursor and return a seq of first names. Think about these collections as primarily intended for use with transducers.

SimpleStore has nothing to do with om/root. Like NativeStore, the intended use is to be 'out of band' of the default om/root. If you use the on-changes macro in your render loop (see bottom of NativeStore file) then the component will be refreshed whenever state in SimpleStore changes, even if the cursors don't change. SimpleStore is a different way to handle data and selective updating, so it does add a bit to the complexity of an Om component.

[viksit]

Thanks for the reply. Could you point me to some sample code utilizing the on-changes macro?

Also, I've yet been unable to use derive - it seems the docs page is broken?