Prvotní nástřel fungující aplikace

client/src/context/auth.tsx

@@ -0,0 +1,58 @@
+import React, { ReactNode, useContext, useState } from "react"
+import { useEffect } from "react"
+
+const LOGIN_KEY = 'login';
+
+export type AuthContextProps = {
+  login?: string,
+  setLogin: (name: string) => void,
+  clearLogin: () => void,
+}
+
+type ContextProps = {
+  children: ReactNode
+}
+
+const authContext = React.createContext<AuthContextProps | null>(null);
+
+export function ProvideAuth(props: ContextProps) {
+  const auth = useProvideAuth();
+  return <authContext.Provider value={auth}>{props.children}</authContext.Provider>
+}
+
+export const useAuth = () => {
+  return useContext(authContext);
+}
+
+function useProvideAuth(): AuthContextProps {
+  const [loginName, setLoginName] = useState<string | undefined>();
+
+  useEffect(() => {
+    const login = localStorage.getItem(LOGIN_KEY);
+    if (login) {
+      setLogin(login);
+    }
+  }, [])
+
+  useEffect(() => {
+    if (loginName) {
+      localStorage.setItem(LOGIN_KEY, loginName)
+    } else {
+      localStorage.removeItem(LOGIN_KEY);
+    }
+  }, [loginName]);
+
+  function setLogin(login: string) {
+    setLoginName(login);
+  }
+
+  function clearLogin() {
+    setLoginName(undefined);
+  }
+
+  return {
+    login: loginName,
+    setLogin,
+    clearLogin
+  }
+}