Added onRenderBody to have IIFE script after body

Signed-off-by: Randy Lau <[email protected]>

Author: randychilau

onRenderBody.js

@@ -0,0 +1,48 @@
+import React from "react";
+import { DarkThemeKey, ThemeSetting } from "./src/theme/app/ThemeManager.js";
+import lighttheme, { darktheme } from "./src/theme/app/themeStyles";
+
+const themes = { light: lighttheme, dark: darktheme };
+
+const MagicScriptTag = (props) => {
+  const codeToRunOnClient = `
+      (function() {
+          const themeFromLocalStorage = localStorage.getItem('${DarkThemeKey}') || '${ThemeSetting.SYSTEM}';
+          const systemDarkModeSetting = () => window.matchMedia ? window.matchMedia('(prefers-color-scheme: dark)') : null;
+          const isDarkModeActive = () => {
+              return !!systemDarkModeSetting()?.matches;
+          };
+          let colorMode;
+          switch (themeFromLocalStorage) {
+              case '${ThemeSetting.SYSTEM}':
+                colorMode = isDarkModeActive() ? '${ThemeSetting.DARK}' : '{ThemeSetting.LIGHT}'
+                break
+              case '${ThemeSetting.DARK}':
+              case '${ThemeSetting.LIGHT}':
+                colorMode = themeFromLocalStorage
+                break
+              default:
+                  colorMode = '${ThemeSetting.LIGHT}'
+            }
+          const root = document.documentElement;
+          const iterate = (obj) => {
+              Object.keys(obj).forEach(key => {
+                 if (typeof obj[key] === 'object') {
+                      iterate(obj[key])
+                 } else {
+                   root.style.setProperty("--" + key, obj[key])
+                 }
+                 })
+          }
+          const parsedTheme = JSON.parse('${JSON.stringify(props.theme)}')
+          const theme = parsedTheme[colorMode]
+          iterate(theme)
+          root.style.setProperty('--initial-color-mode', colorMode);  
+       })()
+  `;
+  return <script dangerouslySetInnerHTML={{ __html: codeToRunOnClient }} />;
+};
+
+export const onRenderBody = ( { setPreBodyComponents }) => {
+  setPreBodyComponents(<MagicScriptTag key="theme-injection" theme={themes} />);
+};