Javascript 认证后未呈现的注销组件变为true这与react router docs中的代码类似
我刚刚尝试在浏览器上构建react router docs ex,但AuthButton组件中存在问题,当isAuthenticated变为true时,它没有显示signOut按钮Javascript 认证后未呈现的注销组件变为true这与react router docs中的代码类似,javascript,reactjs,react-router,react-router-dom,react-router-v4,Javascript,Reactjs,React Router,React Router Dom,React Router V4,我刚刚尝试在浏览器上构建react router docs ex,但AuthButton组件中存在问题,当isAuthenticated变为true时,它没有显示signOut按钮 import React from 'react'; import { BrowserRouter as Router, Switch, Route, Link, Redirect, useHistory, useLocation, } from 'react-
import React from 'react';
import {
BrowserRouter as Router,
Switch,
Route,
Link,
Redirect,
useHistory,
useLocation,
} from 'react-router-dom';
export default function AuthExample() {
return (
<Router>
<div>
<AuthButton />
<ul>
<li>
<Link to='/public'>Public Page</Link>
</li>
<li>
<Link to='/protected'>Protected Page</Link>
</li>
</ul>
<Switch>
<Route path='/public'>
<PublicPage />
</Route>
<Route path='/login'>
<LoginPage />
</Route>
<PrivateRoute path='/protected'>
<ProtectedPage />
</PrivateRoute>
</Switch>
</div>
</Router>
);
}
const fakeAuth = {
isAuthenticated: false,
authenticate(cb) {
fakeAuth.isAuthenticated = true;
setTimeout(cb, 100); // fake async
},
signout(cb) {
fakeAuth.isAuthenticated = false;
setTimeout(cb, 100);
},
};
function AuthButton() {
let history = useHistory();
return fakeAuth.isAuthenticated ? (
<p>
Welcome!{' '}
<button
onClick={() => {
fakeAuth.signout(() => history.push('/'));
}}>
Sign out
</button>
</p>
) : (
<p>You are not logged in.</p>
);
}
function PrivateRoute({ children, ...rest }) {
return (
<Route
{...rest}
render={({ location }) =>
fakeAuth.isAuthenticated ? (
children
) : (
<Redirect
to={{
pathname: '/login',
state: { from: location },
}}
/>
)
}
/>
);
}
function PublicPage() {
return <h3>Public</h3>;
}
function ProtectedPage() {
return <h3>Protected</h3>;
}
function LoginPage() {
let history = useHistory();
let location = useLocation();
let { from } = location.state || { from: { pathname: '/' } };
let login = () => {
fakeAuth.authenticate(() => {
history.replace(from);
});
};
return (
<div>
<p>You must log in to view the page at {from.pathname}</p>
<button onClick={login}>Log in</button>
</div>
);
}
我认为问题出在渲染过程中。 在我看来,如果你把子函数放到导出函数中,这个问题可能会解决 如果问题无法解决,请尝试使用类基组件来处理此渲染过程
祝您成功它不更新的原因是因为它不知道如何更新。您更改了路线,但AuthButton不知道根据需要传递道具的路线重新渲染,以便它知道何时更新。我重构了您的代码以使用。通过使用钩子,您可以通过useState在AuthExample的本地状态中存储isAuthenticated 在AuthExample中,将isAuthenticated的状态值作为道具传递给AuthButton。如果道具更改,AuthButton将检测到它,这将触发AuthButton的重新渲染,并反映您正在寻找的正确组件结构。见下文
import React, { useState } from "react";
import {
BrowserRouter as Router,
Switch,
Route,
Link,
Redirect,
useHistory,
useLocation
} from "react-router-dom";
export default function AuthExample() {
const [isAuthenticated, setIsAuthenticated] = useState(false);
const fakeAuth = {
isAuthenticated: isAuthenticated,
authenticate(cb) {
fakeAuth.isAuthenticated = true;
setIsAuthenticated(true);
setTimeout(cb, 100); // fake async
},
signout(cb) {
setIsAuthenticated(false);
fakeAuth.isAuthenticated = false;
setTimeout(cb, 100);
}
};
return (
<Router>
<div>
<AuthButton fakeAuth={fakeAuth} isAuthenticated={isAuthenticated} />
<ul>
<li>
<Link to="/public">Public Page</Link>
</li>
<li>
<Link to="/protected">Protected Page</Link>
</li>
</ul>
<Switch>
<Route path="/public">
<PublicPage />
</Route>
<Route path="/login">
<LoginPage fakeAuth={fakeAuth} />
</Route>
<PrivateRoute path="/protected" fakeAuth={fakeAuth}>
<ProtectedPage />
</PrivateRoute>
</Switch>
</div>
</Router>
);
}
function AuthButton(props) {
const { fakeAuth, isAuthenticated } = props;
let history = useHistory();
return isAuthenticated ? (
<p>
Welcome!{" "}
<button
onClick={() => {
fakeAuth.signout(() => history.push("/"));
}}
>
Sign out
</button>
</p>
) : (
<p>You are not logged in.</p>
);
}
function PrivateRoute({ children, ...rest }) {
const { fakeAuth } = rest;
return (
<Route
{...rest}
render={({ location }) =>
fakeAuth.isAuthenticated ? (
children
) : (
<Redirect
to={{
pathname: "/login",
state: { from: location }
}}
/>
)
}
/>
);
}
function PublicPage() {
return <h3>Public</h3>;
}
function ProtectedPage() {
return <h3>Protected</h3>;
}
function LoginPage(props) {
const { fakeAuth } = props;
let history = useHistory();
let location = useLocation();
let { from } = location.state || { from: { pathname: "/" } };
let login = () => {
fakeAuth.authenticate(() => {
history.replace(from);
});
};
return (
<div>
<p>You must log in to view the page at {from.pathname}</p>
<button onClick={login}>Log in</button>
</div>
);
}
您还可以看到一个工作示例。有几种方法可以做到这一点,但是钩子使操作状态值来更新功能组件变得很容易,而不必使它们成为类组件。这种方法还可以保持大部分代码的完整性,因为只需添加一些检查,以确定何时更新了isAuthenticated。这应该是一个注释,而不是回答。这是您的意见,tnx@artmSkoltz的意思是,内容不足以作为答案,因为它不包含真正的解决方案、代码或引用,相反,它给出的是简短的建议和模糊的解决方案。将来一定要包含代码和/或引用,这样解决方案就更具体,而不是抽象的想法。谢谢,我下次会记得它。您的AuthButton似乎未连接到身份验证,因此在连接到身份验证之前它不会更改。尝试使用上下文允许其接收isAuthenticated