Om Next mutation with validation (thin.ng/validate)

gistfile1.txt

;;;; Parser

(def card-schema
  {:id        [(v/number) (v/pos)]
   :assignees [(v/optional (v/vector))]
   :text      [(v/string) (v/min-length 1 "The description may not be empty")]})

(defn validate-card [card]
  (assoc card :errors (second (v/validate card card-schema))))

(defmethod mutate 'cards/update
  [{:keys [state]} _ {:keys [card data]}]
  {:value [:cards]
   :action #(swap! state update-in card (comp validate-card merge) data)})
   
;;;; Component

(defui CardEditor
  static om/Ident
  (ident [this props]
    [:card/by-id (:id props)])
  static om/IQuery
  (query [this]
    [:id :text {:assignees (om/get-query Assignee)} :errors])
  Object
  (render [this]
    (let [{:keys [id text assignees errors]} (om/props this)]
      ...
      (when (:assignees errors)
        (dom/ul nil
          (map-indexed #(dom/li #js {:key %1} %2) (:assignees errors))))
      ...
      (when (:text errors)
        (dom/ul nil
          (map-indexed #(dom/li #js {:key %1} %2) (:text errors))))
      ...)))