fix: move theme class to root node to prevent white flash (#392)

Alexander Sohn

18.46.2022 c36e1d8fff70ab6a817e00aa053b996342554681

 assets/js/anatole-theme-switcher.js

@@ -1,11 +1,11 @@
const getStoredThemeStyle = () => localStorage.getItem('theme');

const setThemeClass = (style) => {
  const body = document.body;
  const prevTheme = [...body.classList].find((c) => c.match(/theme--(light|dark)/));
  const html = document.documentElement;
  const prevTheme = [...html.classList].find((c) => c.match(/theme--(light|dark)/));
  if (!prevTheme) return;
  body.classList.remove(prevTheme);
  body.classList.add(`theme--${style}`);
  html.classList.remove(prevTheme);
  html.classList.add(`theme--${style}`);
};

const setThemeStyle = (style) => {
@@ -28,16 +28,6 @@
  }
};

const initTheme = () => {
  const currThemeStyle = getStoredThemeStyle();
  if (currThemeStyle) {
    setThemeStyle(currThemeStyle);
    return;
  }
  const userPrefersDark = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches;
  if (!userPrefersDark) return;
  setThemeStyle('dark');
};

document.addEventListener(
  'DOMContentLoaded',
@@ -50,4 +40,12 @@

window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', switchTheme, false);

document.addEventListener('DOMContentLoaded', () => initTheme());
const currThemeStyle = getStoredThemeStyle();
if (currThemeStyle) {
  setThemeStyle(currThemeStyle);
} else {
  const userPrefersDark = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches;
  if (userPrefersDark) {
    setThemeStyle('dark');
  }
}