Question

我使用基于gapi（Google Auth）API的基于类的组件，该API呈现按钮并且可以正常工作：

import React from 'react';

class GoogleAuth extends React.Component {
  state = { isSignedIn: null };

  componentDidMount() {
    window.gapi.load('client:auth2', () => {
      window.gapi.client
        .init({
          clientId: process.env.REACT_APP_CLIENT_ID,
          scope: 'email',
        })
        .then(() => {
          this.auth = window.gapi.auth2.getAuthInstance();
          this.handleAuthChange();
          this.auth.isSignedIn.listen(this.handleAuthChange);
        });
    });
  }

  handleAuthChange = () => {
    this.setState({ isSignedIn: this.auth.isSignedIn.get() });
  };

  handleSignIn = () => {
    this.auth.signIn();
  };

  handleSignOut = () => {
    this.auth.signOut();
  };

  renderAuthButton() {
    if (this.state.isSignedIn === null) {
      return null;
    } else if (this.state.isSignedIn) {
      return <button onClick={this.handleSignOut}>Sign Out</button>;
    } else {
      return <button onClick={this.handleSignIn}>Sign in with Google</button>;
    }
  }

  render() {
    return <div>{this.renderAuthButton()}</div>;
  }
}

export default GoogleAuth;

我很难将其转换为使用钩子。主要问题是this.auth ...这就是类对window.gapi.auth2.getAuthInstance()的引用

我尝试了许多不同的方法，包括将auth保持在如下状态：

export default function GoogleAuth() {
    const [isSignedIn, setIsSignedIn] = useState(null);
    const [auth, setAuth] = useState(null);
    useEffect(() => {
        window.gapi.load('client:auth2', () => {
            window.gapi.client
                .init({
                    clientId: process.env.REACT_APP_CLIENT_ID,
                    scope: 'email',
                })
                .then(() => {
                    setAuth(window.gapi.auth2.getAuthInstance());
                    setIsSignedIn(auth.isSignedIn.get());
                    auth.isSignedIn.listen(() => setIsSignedIn(auth.isSignedIn.get()));
                });
        });
    }, [auth]);

Answer 1

夫妇问题-设置状态后，您将立即引用auth-auth直到重新赋予其新状态后才会被设置。

我正在使用类似的代码，因此我不得不在初始设置中使用window.gapi来正确访问返回的auth实例。

我想如果在设置auth之前用户快速单击就可以捕获它，那么它可能会引发错误，但是我发现登录/注销功能能够处理此错误。

我还发现最容易在隐身模式下进行测试，因为cookie和api的缓存似乎创建了一个不可预测的本地测试环境。

My current component state

Answer 2

仅8个月后，但尝试使用带有auth的useRef，如下所示。它对我有用。

   const GoogleAuth  = () => {
      const [isSignedIn, setSignedIn] = useState(null)
      const auth = useRef(null);
      useEffect(() => {
        window.gapi.load('client:auth2', () => {
          window.gapi.client.init({
            clientId:
              'jcu.apps.googleusercontent.com',
            scope: 'email'
          }).then(() => {
            auth.current = window.gapi.auth2.getAuthInstance();
            setSignedIn(auth.current.isSignedIn.get());
            auth.current.isSignedIn.listen(onAuthChange)
          });
        });
      }, [isSignedIn]);
    
     const onAuthChange = () => {
          setSignedIn(auth.current.isSignedIn.get())
      }
    
     if (isSignedIn === null) {
        return (
          <div>I don't know if we are signed in!</div>
        );
      } else if ( isSignedIn ){
        return (
          <div>I am signed in!</div>
        );
      } else {
        return ( <div>I am not signed in. :(</div>);
      }
    }

将基于类的组件转换为挂钩（gapi API）

2 个答案: