splitting all js into individual files to comparmentalize and getting rid of onload event (in favour of defer)

HaWeb/wwwroot/js/theme.js

@@ -0,0 +1,30 @@
+// Functions for switching theme
+const go_to_dark = function () {
+    localStorage.setItem("theme", "ha-toggledark");
+    document.documentElement.classList.add("dark");
+};
+
+const go_to_bright = function () {
+    document.documentElement.classList.remove("dark");
+    localStorage.setItem("theme", "ha-togglebright");
+};
+
+// Functions for reading theme settings
+const get_theme_settings = function (standard) {
+    var theme = localStorage.getItem("theme");
+    if (theme === null) theme = standard;
+    let toggleSwitch = document.getElementById(theme).click();
+};
+
+if (
+    document.getElementById("ha-togglebright") !== null &&
+    this.document.getElementById("ha-toggledark") !== null
+) {
+    document
+        .getElementById("ha-togglebright")
+        .addEventListener("click", go_to_bright);
+    document
+        .getElementById("ha-toggledark")
+        .addEventListener("click", go_to_dark);
+}
+get_theme_settings("ha-togglebright");