React-router v6 实现登录验证流程

此示例演示了一个包含三个页面的简单登录流程：公共页面、受保护页面和登录页面。 为了查看受保护的页面，你必须先登录。
首先，访问公共页面。 然后，访问受保护的页面。 你尚未登录，因此你将被重定向到登录页面。 登录后，你将被重定向回受保护的页面。

封装 Context 包裹容器

首先封装AuthProvider组件，利用Context特性共享那些对于一个组件树而言是“全局”的数据。
全局定义user、signIn、signOut数据和方法，signIn、signOut使用了高阶函数，也方便后续扩展和修改。

Context主要应用场景在于很多不同层级的组件需要访问同样一些的数据。请谨慎使用，因为这会使得组件的复用性变差。
如果你只是想避免层层传递一些属性，组件组合（component composition）有时候是一个比 Context更好的解决方案。

import { ReactNode, createContext, useState } from "react";

export interface AuthContextType {
  user: any;
  signIn: (user: string, callback: VoidFunction) => void;
  signOut: (callback: VoidFunction) => void;
}

export let AuthContext = createContext<AuthContextType | null>(null);

const fakeAuthProvider = {
  isAuthenticated: false,
  signIn(callback: VoidFunction) {
    this.isAuthenticated = true;
    setTimeout(callback, 100);
  },
  signOut(callback: VoidFunction) {
    this.isAuthenticated = false;
    setTimeout(callback, 100);
  },
};

const AuthProvider = ({ children }: { children: ReactNode }) => {
  const [user, setUser] = useState<any>(null);

  let signIn = (newUser: string, callback: VoidFunction) => {
    return fakeAuthProvider.signIn(() => {
      setUser(newUser);
      callback();
    });
  };

  let signOut = (callback: VoidFunction) => {
    return fakeAuthProvider.signOut(() => {
      setUser(null);
      callback();
    });
  };

  return (
    <AuthContext.Provider value={{ user, signIn, signOut }}>
      {children}
    </AuthContext.Provider>
  );
};

export default AuthProvider;
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封装 Layout 父级容器

Layout组件主要是针对登录状态进行校验，然后做相应处理。利用react-router v6中<Outlet />组件显示嵌套路由，相比于v5版本v6实现嵌套路由更加方便，省略了很多冗余的判断代码。

import { useContext } from "react";
import { useNavigate, Link, Outlet } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

const useAuth = () => useContext(AuthContext);

const AuthStatus = () => {
  let auth = useAuth();
  let { user, signOut } = auth as AuthContextType;
  let navigate = useNavigate();

  if (!user) return <p>没有登录</p>;
  return (
    <>
      <p>你好 {user}! </p>
      <button onClick={() => signOut(() => navigate("/"))}>退出</button>
    </>
  );
};

const Layout = () => {
  return (
    <div>
      <AuthStatus />
      <ul>
        <li>
          <Link to="/">公共页面</Link>
        </li>
        <li>
          <Link to="/protected">受保护页面</Link>
        </li>
      </ul>
      <Outlet />
    </div>
  );
};

export default Layout;
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开发 Login 模块

import { useContext, FormEvent } from "react";
import { useNavigate, useLocation, Location } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

interface State extends Omit<Location, "state"> {
  state: {
    from: {
      pathname: string;
    };
  };
}

const useAuth = () => useContext(AuthContext);

const Login = () => {
  let auth = useAuth();
  let { signIn } = auth as AuthContextType;
  const { state } = useLocation() as State;
  let from = state.from.pathname || "/";
  let navigate = useNavigate();

  const handleSubmit = (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault();

    let formData = new FormData(event.currentTarget);
    let username = formData.get("username") as string;

    signIn(username, () => navigate(from, { replace: true }));
  };

  return (
    <div>
      <p>您必须登录才能查看该页面 {from}</p>

      <form onSubmit={handleSubmit}>
        <label>
          用户名: <input name="username" type="text" />
        </label>
        <button type="submit">登录</button>
      </form>
    </div>
  );
};

export default Login;
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开发 Protected 包裹容器

主要就是对登录状态进行校验，成功则渲染子组件，否则跳转回登录页面

import { useContext } from "react";
import { useLocation, Navigate } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

const useAuth = () => useContext(AuthContext);

const RequireAuth = ({ children }: { children: JSX.Element }) => {
  let auth = useAuth();
  let { user } = auth as AuthContextType;
  let location = useLocation();

  if (!user) return <Navigate to="/login" state={{ from: location }} replace />;

  return children;
};

export default RequireAuth;
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App 入口文件

入口文件没有对路由进行懒加载优化，因为是小应用，所以实际开发还是要考虑性能优化的。

import { Routes, Route } from "react-router-dom";

import AuthProvider from "src/views/AuthProvider";
import Layout from "src/views/auth/layout";
import LoginPage from "src/views/auth/login";
import PublicPage from "src/views/auth/publicPage";
import RequireAuth from "src/views/auth/requireAuth";
import ProtectedPage from "src/views/auth/protectedPage";

const App = () => {
  return (
    <AuthProvider>
      <Routes>
        <Route element={<Layout />}>
          <Route path="/" element={<PublicPage />} />
          <Route path="/login" element={<LoginPage />} />
          <Route
            path="/protected"
            element={
              <RequireAuth>
                <ProtectedPage />
              </RequireAuth>
            }
          />
        </Route>
      </Routes>
    </AuthProvider>
  );
};

export default App;
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参考资料：
React Router官方文档