A curious case.

hmm_om.cljs

(def hmm-state (atom {:value "Hmm..."}))

(defn hmm [state owner]
  (reify
    om/IRender
    (render [_]
      (om.dom/textarea #js {:value (:value state)
                            :onChange (fn [e] (.log js/console (.. e -target -value)))}))))

(om/root
  hmm
  hmm-state
  {:target (. js/document (getElementById "app"))})

Without the onChange handler, you can't change the value of the textarea because the textarea is controlled. This is what I would expect. When you add the onChange handler, you're able to change the value of the textarea even though the onChange handler doesn't update the app state, effectively making the textarea uncontrolled (or at least act like it's uncontrolled). Why is this?

This is with Om 0.6.4 and ClojureScript 2268.