set-state! on already deleted node about om

[swannodette]

Thanks for the report. Can you please produce a complete minimal example so we can easily reproduce? Thank you!

[thheller]

I had similar moments before, not in Om though, but the issue at hand is that first the event dom/a on-delete is fired which deletes the item and then bubbles up to dom/li on-mark, your fix is pretty much the way to go here.

Don't think its an issue with Om, apart from maybe warning about "dead" components.

[ivo-]

This is the simplest code I was able to reach reproducing the problem. I hope it helps.

(ns om-examples.events
  (:require [om.core :as om :include-macros true]
            [om.dom :as dom :include-macros true]))

(defn on-delete [e item items]
  (.log js/console js/arguments)
  (om/update! items #(vec (remove #{(om/value item)} %))))

(defn item [item node items]
  (om/component
    (dom/li nil
      (dom/a #js {:onClick (om/bind on-delete item items)}))))

(defn app [cursor node]
  (reify
    om/IDidMount
    (did-mount [_ _]
      (let [links (.call (.-slice js/Array.prototype)
                    (.getElementsByTagName js/document "a"))]
        (doseq [l links] (.click l))))
    om/IRender
    (render [_]
      (dom/section nil
        (om/build-all item (:items cursor)
          {:opts (:items cursor)})))))

(om/root {:items [[1] [2] [3]]} app js/document.body)

Here is the output using [om "0.1.4"]:

[SyntheticMouseEvent, om.core.IndexedCursor, om.core.IndexedCursor]
[SyntheticMouseEvent, om.core.IndexedCursor, om.core.IndexedCursor]
[SyntheticMouseEvent, null, om.core.IndexedCursor]
Uncaught Error: No protocol method ICursor.-value defined for type null:  

[swannodette]

Thanks much, will take a look and see if this something we actually need to address.

[swannodette]

This is definitely not an Om bug. There are many cases where this could occur because of concurrency, you need to recheck your assumptions in your event handler before acting.