automatic rejoin on reload or server restart

tank-frontend/src/useStoredState.ts

@@ -0,0 +1,35 @@
+import {useState} from 'react';
+
+export function useStoredState(storageKey: string, initialState: () => string): [string, ((newState: string) => void)] {
+    const [state, setState] = useState<string>(() => localStorage.getItem(storageKey) || initialState());
+
+    const setSavedState = (newState: string) => {
+        localStorage.setItem(storageKey, newState);
+        setState(newState);
+    };
+
+    return [state, setSavedState];
+}
+
+export function useStoredObjectState<T>(
+    storageKey: string,
+    initialState: () => T
+): [T, (mutator: (oldState: T) => T) => void] {
+    const getInitialState = () => {
+        const localStorageJson = localStorage.getItem(storageKey);
+        if (localStorageJson !== null && localStorageJson !== '') {
+            return JSON.parse(localStorageJson);
+        }
+
+        return initialState();
+    };
+
+    const [state, setState] = useState<T>(getInitialState);
+
+    const setSavedState = (mut: (oldState: T) => T) => {
+        localStorage.setItem(storageKey, JSON.stringify(mut(state)));
+        setState(mut);
+    };
+
+    return [state, setSavedState];
+}