Question

我正在尝试创建PrivateRoute（HOC）以测试用户是否已通过身份验证（在redux存储中检查“ auth”是否存在），然后再将其发送到实际路由。问题是在我的身份验证出现在redux存储中之前，privateroute完成了。

console.log第一次运行两次，auth未出现在存储中，但是第二次出现，但是到那时，它已经将用户路由到登录屏幕了。有足够的时间完成提取？当我只想有条件地显示某些内容（例如登录/注销按钮）时，我知道如何执行此条件，但是当尝试有条件地路由某人时，这种方法无效。

import React, { Component } from 'react'
import { connect } from 'react-redux'
import { Route } from 'react-router-dom'

class PrivateRoute extends Component {
  render() {
    const { component: Component, ...rest } = this.props
    console.log(this.props)

    return (
      <Route {...rest} render={(props) => (props.auth ? <Component {...props} /> : props.history.push('/login'))} />
    )
  }
}

function mapStateToProps({ auth }) {
  return { auth }
}

export default connect(mapStateToProps)(PrivateRoute)

Answer 1

我在这里没有使用redux，但是我想您会明白的。希望这会有所帮助，并随时提出任何问题！

import React, { Component } from "react";
import { BrowserRouter, Route, Switch, Redirect } from "react-router-dom";

import Dashboard from "path/to/pages/Dashboard";

class App extends Component {
  state = {
    isLoggedIn: null,
  };

  componentDidMount () {
    // to survive F5
    // when page is refreshed all your in-memory stuff
    // is gone
    this.setState({ isLoggedIn: !!localStorage.getItem("sessionID") });
  }

  render () {
    return (
      <BrowserRouter>
        <Switch>
          <PrivateRoute
            path="/dashboard"
            component={Dashboard}
            isLoggedIn={this.state.isLoggedIn}
          />
          <Route path="/login" component={Login} />

          {/* if no url was matched -> goto login page */}
          <Redirect to="/login" />
        </Switch>
      </BrowserRouter>
    );
  }
}

class PrivateRoute extends Component {
  render () {
    const { component: Component, isLoggedIn, ...rest } = this.props;

    return (
      <Route
        {...rest}
        render={props =>
          isLoggedIn ? <Component {...props} /> : <Redirect to="/login" />
        }
      />
    );
  }
}

class Login extends Component {
  state = {
    login: "",
    password: "",
    sessionID: null,
  };

  componentDidMount () {
    localStorage.removeItem("sessionID");
  }

  handleFormSubmit = () => {
    fetch({
      url: "/my-app/auth",
      method: "post",
      body: JSON.strigify(this.state),
    })
      .then(response => response.json())
      .then(data => {
        localStorage.setItem("sessionID", data.ID);

        this.setState({ sessionID: data.ID });
      })
      .catch(e => {
        // error handling stuff
      });
  };

  render () {
    const { sessionID } = this.state;

    if (sessionID) {
      return <Redirect to="/" />;
    }

    return <div>{/* login form with it's logic */}</div>;
  }
}

Answer 2

动作创建者返回令牌时，需要将其存储在localStorage中。然后您可以创建如下所示的商店

const store = createStore(
    reducers,
    { auth: { authenticated : localStorage.getItem('token') }},
    applyMiddleware(reduxThunk)
)

如果用户已经登录，则令牌将在那里。并且初始状态会在存储区中设置令牌，因此您无需调用任何操作创建者。

现在，您需要通过检查用户是否登录来保护组件。这是这样做的HOC，

import React, { Component } from 'react';
import { connect } from 'react-redux';

export default ChildComponent => {
  class ComposedComponent extends Component {

    componentDidMount() {
      this.shouldNavigateAway();
    }

    componentDidUpdate() {
      this.shouldNavigateAway();
    }
    shouldNavigateAway() {
      if (!this.props.auth) {
        this.props.history.push('/');
      }
    }
    render() {
      return <ChildComponent {...this.props} />;
    }
  }
  function mapStateToProps(state) {
    return { auth: state.auth.authenticated };
  }
  return connect(mapStateToProps)(ComposedComponent);
};

组件渲染为时过早

2 个答案: