state-and-queries.cljs

(ns state_bug.core
  (:require [om.next :as om :refer-macros [defui ui]]
            [om.next :as om]
            [om.dom :as dom]
            [goog.dom :as gdom]))

(enable-console-print!)

(defui C
  static om/IQuery
  (query [this] '[:foo])
  Object
  (render [this]
    (dom/div nil "C: " (str (om/props this))
             (dom/button #js {:onClick (fn [] (om/set-query! this {:query [:bar]}))}
                         "set-query"))))

(def c (om/factory C))

(defui B
  Object
  (initLocalState [this] {:x 1})
  (render [this]
    (let [{:keys [x]} (om/get-state this)]
      (dom/div
       nil
       "B: " x
       (dom/button #js {:onClick (fn [] (om/set-state! this {:x (inc x)}))}
                   "inc")
       (c (om/props this))))))

(def b (om/factory B))

(defui A
  static om/IQuery
  (query [this] `[{:C ~(om/get-query C)}])
  Object
  (render [this]
    (dom/div
     nil
     "A"
     (b (:C (om/props this))))))

(def state
  {:C {:foo "foo" :bar "bar"}})

(defn read [{:keys [query state]} key params]
  {:value (om/db->tree query (get @state key) @state)})

(def reconciler
  (om/reconciler
   {:state (atom state)
    :parser (om/parser {:read read})}))

(om/add-root! reconciler A (gdom/getElement "mount"))