timer.cljs

(defn counter-row [{desc :desc timer :timer active :active bg-color :bg-color}]
      (r/with-let [seconds-elapsed (r/atom 0)
            running (r/atom false)
            timer-fn (atom nil)]
           (fn []
               [:div {:class (str "h-full flex flex-col flex-1 " bg-color " bg-opacity-75 items-center justify-evenly")
                      :on-click (fn []
                                    (if @running (js/clearInterval timer-fn)
                                                 (reset! timer-fn (js/setInterval #(swap! seconds-elapsed inc) 1000)))
                                    (reset! running (not @running))
                                    )}
                [:p {:class "w-full text-9xl text-center text-gray-50"} desc]
                [:p {:class "w-full text-9xl text-center text-gray-50"} @seconds-elapsed]]) 
                  (finally (js/clearInterval timer-fn))))