caption.cljs

(ns solar-system-of-js.caption
  (:require
    [solar-system-of-js.state :refer [state]]
    [markdown.core :refer [md->html]]))

(defn set-caption!
  [caption]
  (let [el (.getElementById js/document "caption")]

    (let [html (md->html caption)]
      (aset el "style" "opacity" "1")
      (aset el "innerHTML" html))

    ;; make all links open in new tab
    (let [elements (.querySelectorAll el "a")]
      (dotimes [i (aget elements "length")]
        (let [el (aget elements i)]
          (.setAttribute el "target" "_blank"))))))

(defn on-caption-change
  [_key _atom {old-caption :caption} {new-caption :caption}]
  (when (not= old-caption new-caption)
    (set-caption! new-caption)))

(add-watch state :caption-watcher on-caption-change)