index.cljs.hl

(page "index.html"
  (:require
    [tailrecursion.hoplon.reload :refer [reload-all]]))

(reload-all 1000)

(defn clamp [lower x upper]
  (max lower (min x upper)))

;; this cell contains some info, but we want to make sure
;; it satisfies some constraint (eg. clamped to some range)
(defc age 0)

;; use javelin "lens" to clamp age to range [0, 100]
(defc= clamped-age age #(reset! age (clamp 0 % 100)))

(html
  (head)
  (body
    (h1 "Hello, World!")
    (form
      (input
        :type   "text"
        :value  clamped-age
        :change #(reset! clamped-age (js/parseInt @%))))))

;; debug cell value to js console
(cell= (prn :clamped-age clamped-age))