minimal example for modifying map entries.

requires both an implementation of `IClonable` for entry types and a
modified version of `om` (cursors for `IClonable`s have to implement
`ITransact`).

clj/clarity/cljs/clarity.cljs

(enable-console-print!)
(extend-type string
  ICloneable
  (-clone [s] (js/String. s)))
; data for one node: type and optionally data
;  if data is present, fill the node with the data
;  on input, check if input conforms to data, if it
;  does change the data, if it doesn't signal the
;  error and don't change the data
(def example-state
  (atom
   {:type 'String
    :data "hello"}))
(defmulti make-typed-input
  (fn [{type :type} & _]
    (if (seq? type)
      (first type)
      type)))
(defn change-data
  ([ev d]
   (om/update! d assoc :data (.. ev -target -value)))
      (keyword name)
      nil)))
(defmethod make-typed-input 'Keyword [d owner]
  (reify
    om/IRender
    (render [_]
      (dom/input #js {:type text
                      :value (om/read d :data)
                      :placeholder ":my.ns/identifier"
                      :pattern "^:(\\w+|\\w+(\\.\\w+)*\\/\\w+)$"
                      :onChange #(change-data % d valid? read-keyword)}))))
(defn typed-string [string owner]
  (om/component
    (dom/input #js {:type "text"
                    :className "field"
                    :value (om/value string)
                    :onChange #(om/update! string (fn [o n] n) (.. % -target -value))})))
(defmethod make-typed-input 'String [d owner]
(defn typed-input [data owner]
  (reify
    om/IWillUpdate
    (will-update [_ p s] (prn p s))
    om/IRender
    (render [_]
      (dom/input #js {:type "text"
                      :value (om/read d :data)
                      :onChange #(change-data % d)}))))
      (dom/div nil
        (dom/span nil "{")
        (om/build typed-string (:str data))
        (dom/span nil "}")))))
(def app-state
  (atom
    {:kw :hello
     :str "hello"
     :many [1 2 3]}))
(om/root (atom {:type 'Keyword}) make-typed-input (.getElementById js/document "typed_input"))
(om/root app-state typed-input (.getElementById js/document "typed_input"))

clj/clarity/project.clj

                 [com.datomic/datomic-free "0.9.4331"]
                 [om "0.1.5"]
                 [om "0.1.6"]
                 [ring "1.2.1"]
                 [compojure "1.1.6"]
  :ring {:handler clarity.server/app}
  :cljsbuild {:crossovers [clarity.types]
              :crossover-path "target/crossover"
              :builds [{:source-paths ["cljs"]}]})
              :builds [{:source-paths ["om/src" "cljs"]}]})