Clojurescript/Reagent处理错误

Question

我们正在开始使用Clojuescript/Reagent作为我们产品的下一个开发阶段。基本上，我们需要一种方法，对原子进行一次操作，我们想出了一种方法：(def app-state (r/atom {}))。

(defn select [index]
    (swap! app-state
       #(-> %
            (assoc-in [:storyboard :pages 0 :layers 0 :children 0 :is_selected] true)
            (assoc-in (GET ....)) ;; ajax call
            (assoc-in [:selected :selected_tab] "tab_properties")
            (assoc-in [:selected :page_object_cursor] [0])
         )))

基本上，交换得到一个函数，其中所有需要的操作都是链式的。太精彩了。然而，我正在寻找处理错误的方法。我希望有一个单独的原子来处理错误：

(def errors (r/atom []))

当发生错误时，捕获它并将其添加到错误中，而不需要交换应用程序状态(应用程序仍处于最后一个稳定状态)。所以我们用链子上的抛球和一种尝试式的仙人掌

(defn change-title [title]
  (try
    (swap! app-state
       #(-> %
            (assoc :text title)
            ((fn [state] 
               (throw "there is an error")))
            ))
    (catch js/Object e
      (swap! errors conj e))))

因此，我希望错误会被捕捉到，而@ error就会被捕获。但现实是：

*不知道有一个错误

core.cljs?rel=1450266738018:108executeDispatch @ react-with-addons.inc.js:3311SimpleEventPlugin.executeDispatch react-with-addons.inc.js:17428forEachEventDispatch react-with-addons.inc.js:3299executeDispatchesInOrder react-with-addons.inc.js:3320executeDispatchesAndRelease react-with-addons.inc.js:2693forEachAccumulated react-with-addons.inc.js:19430EventPluginHub.processEventQueue react-with-addons.inc.js:2900runEventQueueInBatch @react with-addons.inc.js:11217ReactEventEmitterMixin.handleTopLevel @ react-with-addons.inc.js:11243handleTopLevelImpl @ react-with-addons.inc.js:11329Mixin.perform @ react-with-addons.inc.js:18402ReactDefaultBatchingStrategy.batchedUpdates @react-with-addons.inc.js:9669 9669batchedUpdates@ react-with-addons.inc.js:16633ReactEventListener.dispatchEvent @ react-with-addons.inc.js:11423*

Answer 1

(catch :default e
  (swap! errors conj e))))

因为抛出的字符串不是对象，而是字符串！