union_migration_bug.cljs

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

(enable-console-print!)

(def init-data
  {:dashboard/items
   [{:id 0
     :type :post
     :title "Ohai"}]})

(defui Post
  static om/IQuery
  (query [this]
    [:id :type :title]))

(def post (om/factory Post))

(defui DashboardItem
  static om/Ident
  (ident [this {:keys [id type]}]
    [type id])

  static om/IQuery
  (query [this]
    {:post (om/get-query Post)}))

(def dashboard-item (om/factory DashboardItem))

(defui Dashboard
  static om/IQuery
  (query [this]
    [{:dashboard/items (om/get-query DashboardItem)}]))

(defmulti read om/dispatch)

(defmethod read :dashboard/items
  [{:keys [state query]} k _]
  (let [st @state]
    {:value (om/db->tree query (get-in st k) st)}))

(defmulti mutate om/dispatch)

(defmethod mutate 'item/add
  [{:keys [state]} k {:keys [id type] :as params}]
  (let [ident [type id]]
    {:action (fn [] (swap! state (fn [st]
                                  (-> st
                                      (assoc-in ident params)
                                      (update :dashboard/items conj ident)))))
     :remote true}))

(defn api
  [remotes cb]
  (cb {'item/add {:tempids {[:post -1] [:post 99]}}}))

(def reconciler
  (om/reconciler
    {:state  init-data
     :parser (om/parser {:read read :mutate mutate})
     :send api
     :id-key :id}))

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

(comment
  (om/transact! reconciler '[(item/add {:id -1 :type :post :content "..."})])
  (println @reconciler) ;; => {:dashboard/items [[nil nil] [nil nil]], nil {nil {}}, :om.next/tables #{nil}}
)