gistfile1.txt

(page "index.html")

(let [msg (cell nil)]
  (defn dialog! [m]
    (reset! msg m))
  (defelem ok-dialog [attrs kids]
    (div
      :css {:position "absolute"
            :width "300px"
            :left "50%"
            :top "50%"
            :transform "translate(-50%, -50%)"
            :border "3px solid black"
            :padding "10px"}
      :toggle msg
      :id "dialog-box"
      (h4 msg)
      (button :click #(reset! msg nil) "OK"))))
(html
  (head
    (link :href "app.css" :rel "stylesheet"))
  (body
    (ok-dialog)
    (h1 "Hello, Hoplon!")
    (button :click #(dialog! "Hello from button") "See dialog")))