如何使用 react-router <Prompt> 显示组件以防止或允许路由更改

Question

我目前正在尝试找到一种方法来显示自定义组件（如 Modal）以使用该Prompt组件确认路由更改。

Promp组件的默认行为是显示带有消息的确认对话框，如您在此示例中所见：React Router：防止转换。

注意：我正在使用该<BrowserRouter>组件。

路由器有一个propnamed getUserConfirmation，您可以使用它来自定义<Prompt>组件的行为。

// this is the default behavior

function getConfirmation(message, callback) {
  const allowTransition = window.confirm(message);
  callback(allowTransition);
}

<BrowserRouter getUserConfirmation={getConfirmation} />;

我正在尝试做的事情：

• 父组件APP内部
  • 我将confirm状态设置为 true，以显示<Confirm>组件
  • 我正在尝试callback将getConfirmation函数从函数传递给<Confirm>组件以调用它true以允许转换，并false阻止它。
  • true or false如上所示，将在默认行为中调用回调。

function getConfirmation(message, callback) {
    console.log("Inside getConfirmation function...");
    setConfirmCallback(callback);
    setConfirm(true);
    // const allowTransition = window.confirm(message);
    // callback(allowTransition);
  }

这是App.js渲染的内容：

return (
    <Router getUserConfirmation={getConfirmation}>
      <AllRoutes />
      {confirm && (
        <Confirm confirmCallback={confirmCallback} setConfirm={setConfirm} />
      )}
    </Router>
  );

似乎是什么问题：

• 该confirm对话框似乎在那时阻止了该功能。所以callback变量/参数仍在范围内。所以一切正常。
• 当我删除confirm对话框时，该函数一直运行。当我点击<Confirm>组件内的确认按钮时，callback不再存在。

题

有没有人知道使用react-router-dom?

链接到 CodeSandbox

CodeSandbox 的完整代码：

import React, { useState } from "react";
import ReactDOM from "react-dom";
import {
  BrowserRouter as Router,
  Route,
  Switch,
  Link,
  Prompt
} from "react-router-dom";

import "./styles.css";

function App() {
  console.log("Rendering App...");

  const [confirm, setConfirm] = useState(false);
  const [confirmCallback, setConfirmCallback] = useState(null);

  function getConfirmation(message, callback) {
    console.log("Inside getConfirmation function...");
    setConfirmCallback(callback);
    setConfirm(true);
    // const allowTransition = window.confirm(message);
    // callback(allowTransition);
  }

  return (
    <Router getUserConfirmation={getConfirmation}>
      <AllRoutes />
      {confirm && (
        <Confirm confirmCallback={confirmCallback} setConfirm={setConfirm} />
      )}
    </Router>
  );
}

function Confirm(props) {
  function allowTransition() {
    props.setConfirm(false);
    props.confirmCallback(true);
  }

  function blockTransition() {
    props.setConfirm(false);
    props.confirmCallback(false);
  }

  return (
    <React.Fragment>
      <div>Are you sure?</div>
      <button onClick={allowTransition}>Yes</button>
      <button onClick={blockTransition}>No way</button>
    </React.Fragment>
  );
}

function AllRoutes(props) {
  console.log("Rendering AllRoutes...");
  return (
    <Switch>
      <Route exact path="/" component={Home} />
      <Route exact path="/comp1" component={Component1} />
    </Switch>
  );
}

function Home(props) {
  console.log("Rendering Home...");
  return (
    <React.Fragment>
      <div>This is Home</div>
      <ul>
        <li>
          <Link to="/comp1">Component1</Link>
        </li>
      </ul>
    </React.Fragment>
  );
}

function Component1(props) {
  console.log("Rendering Component1...");

  const [isBlocking, setIsBlocking] = useState(true);

  return (
    <React.Fragment>
      <Prompt
        when={isBlocking}
        message={location =>
          `Are you sure you want to go to ${location.pathname}`
        }
      />
      <div>This is component 1</div>
      <Link to="/">Home</Link>
    </React.Fragment>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

Answer 1

受到这个讨论和这个例子的启发，我能够让我的例子工作。

问题是<Confirm>在创建时，setConfirmCallback()调用还没有完成。因此该<Confirm>组件无法使用callbackfrom getUserConfirmation。

所以我改变了这一行：

FROM:
  setConfirmCallback(callback);
TO:
  setConfirmCallback(()=>callback);

现在它起作用了！

代码沙盒链接

完整的 CodeSandbox 代码：

import React, { useState } from "react";
import ReactDOM from "react-dom";
import {
  BrowserRouter as Router,
  Route,
  Switch,
  Link,
  Prompt
} from "react-router-dom";

import "./styles.css";

function App() {
  console.log("Rendering App...");

  const [confirm, setConfirm] = useState(false);
  const [confirmCallback, setConfirmCallback] = useState(null);

  function getConfirmation(message, callback) {
    console.log("Inside getConfirmation function...");
    setConfirmCallback(() => callback);
    setConfirm(true);
    // const allowTransition = window.confirm(message);
    // callback(allowTransition);
  }

  return (
    <Router getUserConfirmation={getConfirmation}>
      <AllRoutes />
      {confirm && (
        <Confirm confirmCallback={confirmCallback} setConfirm={setConfirm} />
      )}
    </Router>
  );
}

function Confirm(props) {
  console.log("Rendering Confirm...");
  function allowTransition() {
    props.setConfirm(false);
    props.confirmCallback(true);
  }

  function blockTransition() {
    props.setConfirm(false);
    props.confirmCallback(false);
  }

  return (
    <React.Fragment>
      <div>Are you sure?</div>
      <button onClick={allowTransition}>Yes</button>
      <button onClick={blockTransition}>No way</button>
    </React.Fragment>
  );
}

function AllRoutes(props) {
  console.log("Rendering AllRoutes...");
  return (
    <Switch>
      <Route exact path="/" component={Home} />
      <Route exact path="/comp1" component={Component1} />
    </Switch>
  );
}

function Home(props) {
  console.log("Rendering Home...");
  return (
    <React.Fragment>
      <div>This is Home</div>
      <ul>
        <li>
          <Link to="/comp1">Component1</Link>
        </li>
      </ul>
    </React.Fragment>
  );
}

function Component1(props) {
  console.log("Rendering Component1...");

  const [isBlocking, setIsBlocking] = useState(true);

  return (
    <React.Fragment>
      <Prompt
        when={isBlocking}
        message={location =>
          `Are you sure you want to go to ${location.pathname}`
        }
      />
      <div>This is component 1</div>
      <Link to="/">Home</Link>
    </React.Fragment>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);