support adding dynamic fields.

clj/clarity/cljs/clarity.cljs

      (om/build make-typed-input m {:opts {:type (om/value t), :key k, :val (k m)
                                           :optional? optional?}}))))
(defn read-string-safe [s default]
  (let [r (r/push-back-reader s)]
    (r/read r false default false)))
(defn update-dynamic-field! [type owner]
  (fn [ev]
    (let [k (om/get-state owner :key)
          t (read-string-safe (om/get-state owner :type) nil)]
      (when (and k t)
        (om/transact! type [4] (fn [optional]
                                 (assoc optional k t)))
        (om/set-state! owner :key nil)
        (om/set-state! owner :type nil)))))
(defn make-dynamic-field [m owner type]
  (om/component
    (dom/div #js {:className "field"}
      (dom/input #js {:type "button", :value "+"
                      :onClick (update-dynamic-field! type owner)})
      (dom/input #js {:type "text", :pattern keyword-pattern, :placeholder ":a.key/word"
                      :value (om/get-state owner :key)
                      :onChange #(om/set-state! owner :key (read-keyword (.. % -target -value)))})
      (dom/input #js {:type "text", :value (om/get-state owner :type)
                      :onChange #(om/set-state! owner :type (.. % -target -value))}))))
(defmethod make-typed-input 'HMap [m owner {type :type}]
  (let [hmap (apply hash-map (rest type))
        required (:mandatory hmap)
        (dom/span nil "{")
        (into-array (map (make-typed-field m false) required))
        (into-array (map (make-typed-field m true) optional))
        (om/build make-dynamic-field m {:opts type})
        (dom/span nil "}")))))
(def app-state