countes.cljs

(def app-state-5 (atom {:a {:key :a :count 13} :b {:key :b :count 33}}))
(defmulti read om/dispatch)
(defmulti mutate om/dispatch)

(defmethod read :default [{:keys [state] :as env} key params]
  (let [st @state]
    (if-let [[_ value] (find st key)]
      {:value value}
      {:value :not-found})))

(defmethod mutate 'increment [{:keys [state] :as env} key params]
   (let [update-key (:key params)]
    {:value {:keys [:count]}
     :action #(swap! state update-in [update-key :count] inc)}))

(defui Counter
  static om/IQuery
  (query [this]
         [:key :count])
  Object
  (render [this]
          (let [{:keys [count key]} (om/props this)]
            (dom/div nil
                     (dom/span nil (str "Count: " count))
                     (dom/br nil nil)
                     (dom/button
                       #js {:onClick
                            (fn [e] (om/transact! this `[(~'increment {:key ~key})]))}
                       "Click me!")))))

(def button-comp (om/factory Counter))
(defui CounterGroup
  static om/IQuery
  (query [this] [{:a (om/get-query Counter)} {:b (om/get-query Counter)}])
  Object
  (render [this]
          (let [st (om/props this) {:keys [count a b]} st]
            (dom/div nil
             (button-comp a)
             (button-comp b)))))

(def reconciler-5
  (om/reconciler
    {:state app-state-5
     :parser (om/parser {:read read :mutate mutate})}))

(om/add-root! reconciler-5
              CounterGroup (gdom/getElement "app"))


(defn log-app-state []
 (let [st @(om/app-state reconciler-5)]
  (binding [*print-namespace-maps* false] (pprint st))))