100% support of utterances

assets/js/theme.js

@@ -1,17 +1,40 @@
-const light = '{{ index .Site.Params.switch 1 }}',
-  dark = '{{ index .Site.Params.switch 0 }}';
-const LIGHT = 'light', DARK = 'dark';
-const themeSwitcher = document.getElementById('theme-switcher');
+const light = '{{ index .Site.Params.switch 1 }}'
+const dark = '{{ index .Site.Params.switch 0 }}'
+const comment = '{{ .Site.Params.comment }}'
+const LIGHT = 'light', DARK = 'dark'
 
-themeSwitcher.innerHTML = localStorage.theme === LIGHT ? light : dark;
+const themeSwitcher = document.getElementById('theme-switcher')
+
+// set switcher
+themeSwitcher.innerHTML = localStorage.theme === LIGHT ? light : dark
 
 themeSwitcher.addEventListener('click', function () {
-  const currentTheme = localStorage.theme,
-    newTheme = currentTheme === LIGHT ? DARK : LIGHT,
-    { classList } = document.documentElement,
-    text = newTheme === LIGHT ? light : dark;
-  classList.remove(currentTheme);
+  const currentTheme = localStorage.theme
+  const newTheme = currentTheme === LIGHT ? DARK : LIGHT
+  
+  // switch global theme
+  switchMinimaTheme(currentTheme, newTheme)
+
+  // switch utterance theme if necessary
+
+  if (comment === 'utterances')
+    switchUtteranceTheme(`github-${newTheme}`)
+});
+
+function switchMinimaTheme(oldTheme, newTheme) {
+  const { classList } = document.documentElement
+  const text = newTheme === LIGHT ? light : dark;
+  
+  classList.remove(oldTheme);
   classList.add(newTheme);
   localStorage.theme = newTheme;
   themeSwitcher.innerHTML = text;
-});
+}
+
+const utteranceClassName = '.utterances-frame'
+let utterance;
+
+function switchUtteranceTheme(theme) {
+  if (!utterance) utterance = document.querySelector(utteranceClassName)
+  utterance.contentWindow.postMessage({type: 'set-theme', theme}, 'https://utteranc.es')
+}