om_data.cljs

(ns om-data.core
  (:require [om.core :as om :include-macros true]
            [om.dom :as dom :include-macros true]
            [datascript :as d]))

(enable-console-print!)

(def schema {})
(def conn (d/create-conn schema))

;; prevent cursor-ification
(extend-type d/DB
  om/IToCursor
  (-to-cursor
    ([this _] this)
    ([this _ _] this)))

(d/transact! conn
  [{:db/id -1
    :title "Hello world!"
    :count 0}])

(defn get-conn [owner]
  (om/get-shared owner :conn))

(defn app-title [db]
  (ffirst
    (d/q
      '[:find ?title
        :where
        [?e :title ?title]]
      db)))

(defn app-count [db]
  (ffirst
    (d/q
      '[:find ?count
        :where
        [?e :count ?count]]
      db)))

(defn app-view [db owner]
  (reify
    om/IRender
    (render [_]
      (let [count (app-count db)]
        (dom/div nil
          (dom/h2 nil (app-title db))
          (dom/div nil
            (dom/span nil count)
            (dom/button
              #js {:style #js {:marginLeft "5px"}
                   :onClick
                   (fn [e]
                     (d/transact! (get-conn owner)
                       [[:db/add 1 :count (inc count)]])
                     (om/refresh! owner))}
              "+")))))))

(om/root app-view conn
  {:shared {:conn conn}
   :target (. js/document (getElementById "app"))})