gistfile1.clj

(comment
  I'm trying to build a very simple clojurescript app using re-frame (& reagent, secretary),
  and I am getting the following error in the console, that I can't seem to debug:
  
  Error: No protocol method IDeref.-deref defined for type cljs.core/PersistentArrayMap: {:name "Black Temple", :snippet "25-man raid"}
)

(ns raid-commander.core
    (:require [reagent.core :as reagent :refer [atom]]
              [reagent.session :as session]
              [secretary.core :as secretary :include-macros true]
              [goog.events :as events]
              [goog.history.EventType :as EventType]
              [re-frame.core :as re-frame])
    (:require-macros [reagent.ratom :refer [reaction]])
    (:import goog.History))

;; -------------------------
;; Re-frame data

(def initial-state
  {:raids [{:name "Black Temple" :snippet "25-man raid"}
           {:name "Tempest Keep" :snippet "25-man raid"}
           {:name "Karazan" :snippet "10-man raid"}]})

;; -------------------------
;; Event Handlers

(re-frame/register-handler
 :initialize
 (fn
   [db _]
   (merge db initial-state)))

;; -------------------------
;; Subscriptions

(re-frame/register-sub
 :raids
 (fn
   [db _]
   (reaction (:raids @db))))

;; -------------------------
;; Views

(defn raid-component [raid]
  [:li
   [:span (:name @raid)]
   [:p (:snippet @raid)]])

(defn raids-component []
  (let [raids (re-frame/subscribe [:raids])]
    (fn []
      [:ul
       (for [raid @raids] ^{:key raid} [raid-component raid])])))

(defn home-page []
  [:div [raids-component]])

(defn current-page []
  [:div [(session/get :current-page)]])

;; -------------------------
;; Routes

(secretary/set-config! :prefix "#")

(secretary/defroute "/" []
  (session/put! :current-page #'home-page))

;; -------------------------
;; History
;; must be called after routes have been defined
(defn hook-browser-navigation! []
  (doto (History.)
    (events/listen
     EventType/NAVIGATE
     (fn [event]
       (secretary/dispatch! (.-token event))))
    (.setEnabled true)))

;; -------------------------
;; Initialize app
(defn mount-root []
  (reagent/render [current-page] (.getElementById js/document "app")))

(defn init! []
  (hook-browser-navigation!)
  (re-frame/dispatch [:initialize])
  (mount-root))

Lines 49/50 had:

@raids

when they needed

raids

Thanks. I killed about an hour trying to figure the same problem out and your comment helped me.
I am still confused why deref is not needed here.