🔧 Save last set theme in the localStorage

code/frontend/src/App.js

@@ -12,10 +12,50 @@ import PageSettings from "./routes/PageSettings"
 
 
 export default function App() {
-    const [theme, setTheme] = useState("ThemeDark");
+    const loadTheme = () => {
+        if(localStorage) {
+            console.debug(`Loading theme from localStorage...`)
+            let value = localStorage.getItem("theme")
+
+            if(value) {
+                console.debug(`Loaded theme ${value}!`)
+                return value
+            }
+            else {
+                console.debug(`There is no theme stored in the localStorage; setting to "ThemeDark"...`)
+                return "ThemeDark"
+            }
+        }
+        else {
+            console.warn(`Can't load theme; localStorage doesn't seem to be available; setting to "ThemeDark"...`)
+            return "ThemeDark"
+        }
+    }
+
+    const [theme, _setTheme] = useState(loadTheme());
+
+    const setTheme = (value) => {
+        console.debug(`Changing theme to ${value}...`)
+        _setTheme(value)
+    }
+
+    const saveTheme = (value) => {
+        if(localStorage) {
+            console.debug(`Saving theme ${value} to localStorage...`)
+            localStorage.setItem("theme", value)
+        }
+        else {
+            console.warn(`Can't save theme; localStorage doesn't seem to be available...`)
+        }
+    }
+
+    const setAndSaveTheme = (value) => {
+        setTheme(value)
+        saveTheme(value)
+    }
 
     return (
-        <ContextTheme.Provider value={[theme, setTheme]}>
+        <ContextTheme.Provider value={[theme, setAndSaveTheme]}>
         <BrowserRouter>
 
             <div className={classNames(Style.App, theme)}>