javascript - Firebase listener with React Hooks

Question

I am trying to figure out how to use a Firebase listener so that cloud firestore data is refreshed with react hooks updates.

Initially, I made this using a class component with a componentDidMount function to get the firestore data.

this.props.firebase.db
    .collection('users')
    // .doc(this.props.firebase.db.collection('users').doc(this.props.firebase.authUser.uid))
.doc(this.props.firebase.db.collection('users').doc(this.props.authUser.uid))
.get()
.then(doc => {
    this.setState({ name: doc.data().name });
    // loading: false,
  });  
}

That breaks when the page updates, so I am trying to figure out how to move the listener to react hooks.

I have installed the react-firebase-hooks tool - although I can't figure out how to read the instructions to be able to get it to work.

I have a function component as follows:

import React, { useState, useEffect } from 'react';
import { useDocument } from 'react-firebase-hooks/firestore';

import {
    BrowserRouter as Router,
    Route,
    Link,
    Switch,
    useRouteMatch,
 } from 'react-router-dom';
import * as ROUTES from '../../constants/Routes';
import { compose } from 'recompose';
import { withFirebase } from '../Firebase/Index';
import { AuthUserContext, withAuthorization, withEmailVerification, withAuthentication } from '../Session/Index';

function Dashboard2(authUser) {
    const FirestoreDocument = () => {

        const [value, loading, error] = useDocument(
          Firebase.db.doc(authUser.uid),
          //firebase.db.doc(authUser.uid),
          //firebase.firestore.doc(authUser.uid),
          {
            snapshotListenOptions: { includeMetadataChanges: true },
          }
        );
    return (

        <div>    



                <p>
                    {error && <strong>Error: {JSON.stringify(error)}</strong>}
                    {loading && <span>Document: Loading...</span>}
                    {value && <span>Document: {JSON.stringify(value.data())}</span>}
                </p>




        </div>

    );
  }
}

export default withAuthentication(Dashboard2);

This component is wrapped in an authUser wrapper at the route level as follows:

<Route path={ROUTES.DASHBOARD2} render={props => (
          <AuthUserContext.Consumer>
             { authUser => ( 
                <Dashboard2 authUser={authUser} {...props} />  
             )}
          </AuthUserContext.Consumer>
        )} />

I have a firebase.js file, which plugs into firestore as follows:

class Firebase {
  constructor() {
    app.initializeApp(config).firestore();
    /* helpers */
    this.fieldValue = app.firestore.FieldValue;


    /* Firebase APIs */
    this.auth = app.auth();
    this.db = app.firestore();


  }

It also defines a listener to know when the authUser changes:

onAuthUserListener(next, fallback) {
    // onUserDataListener(next, fallback) {
      return this.auth.onAuthStateChanged(authUser => {
        if (authUser) {
          this.user(authUser.uid)
            .get()
            .then(snapshot => {
            let snapshotData = snapshot.data();

            let userData = {
              ...snapshotData, // snapshotData first so it doesn't override information from authUser object
              uid: authUser.uid,
              email: authUser.email,
              emailVerified: authUser.emailVerifed,
              providerData: authUser.providerData
            };

            setTimeout(() => next(userData), 0); // escapes this Promise's error handler
          })

          .catch(err => {
            // TODO: Handle error?
            console.error('An error occured -> ', err.code ? err.code + ': ' + err.message : (err.message || err));
            setTimeout(fallback, 0); // escapes this Promise's error handler
          });

        };
        if (!authUser) {
          // user not logged in, call fallback handler
          fallback();
          return;
        }
    });
  };

Then, in my firebase context setup I have:

import FirebaseContext, { withFirebase } from './Context';
import Firebase from '../../firebase';
export default Firebase;
export { FirebaseContext, withFirebase };

The context is setup in a withFirebase wrapper as follows:

import React from 'react';
const FirebaseContext = React.createContext(null);

export const withFirebase = Component => props => (
  <FirebaseContext.Consumer>
    {firebase => <Component {...props} firebase={firebase} />}
  </FirebaseContext.Consumer>
);
export default FirebaseContext;

Then, in my withAuthentication HOC, I have a context provider as:

import React from 'react';
import { AuthUserContext } from '../Session/Index';
import { withFirebase } from '../Firebase/Index';

const withAuthentication = Component => {
  class WithAuthentication extends React.Component {
    constructor(props) {
      super(props);
      this.state = {
        authUser: null,
      };  
    }

    componentDidMount() {
      this.listener = this.props.firebase.auth.onAuthStateChanged(
        authUser => {
           authUser
            ? this.setState({ authUser })
            : this.setState({ authUser: null });
        },
      );
    }

    componentWillUnmount() {
      this.listener();
    };  

    render() {
      return (
        <AuthUserContext.Provider value={this.state.authUser}>
          <Component {...this.props} />
        </AuthUserContext.Provider>
      );
    }
  }
  return withFirebase(WithAuthentication);

};
export default withAuthentication;

Currently - when I try this, I get an error in the Dashboard2 component that says:

Firebase' is not defined

I tried lowercase firebase and get the same error.

I also tried firebase.firestore and Firebase.firestore. I get the same error.

I'm wondering if I can't use my HOC with a function component?

I have seen this demo app and this blog post.

Following the advice in the blog, I made a new firebase/contextReader.jsx with:

 import React, { useEffect, useContext } from 'react';
import Firebase from '../../firebase';



export const userContext = React.createContext({
    user: null,
  })

export const useSession = () => {
    const { user } = useContext(userContext)
    return user
  }

  export const useAuth = () => {
    const [state, setState] = React.useState(() => 
        { const user = firebase.auth().currentUser 
            return { initializing: !user, user, } 
        }
    );
    function onChange(user) {
      setState({ initializing: false, user })
    }

    React.useEffect(() => {
      // listen for auth state changes
      const unsubscribe = firebase.auth().onAuthStateChanged(onChange)
      // unsubscribe to the listener when unmounting
      return () => unsubscribe()
    }, [])

    return state
  }  

Then I try to wrap my App.jsx in that reader with:

function App() {
  const { initializing, user } = useAuth()
  if (initializing) {
    return <div>Loading</div>
  }

    // )
// }
// const App = () => (
  return (
    <userContext.Provider value={{ user }}> 


    <Router>
        <Navigation />
        <Route path={ROUTES.LANDING} exact component={StandardLanding} />

When I try this, I get an error that says:

TypeError: _firebase__WEBPACK_IMPORTED_MODULE_2__.default.auth is not a function

I have seen this post dealing with that error and have tried uninstalling and reinstalling yarn. It makes no difference.

When I look at the demo app, it suggests that context should be created using an 'interface' method. I can't see where this is coming from - I can't find a reference to explain it in the documentation.

I can't make sense of the instructions other than to try what I have done to plug this in.

I have seen this post which attempts to listen to firestore without using react-firebase-hooks. The answers point back to trying to figure out how to use this tool.

I have read this excellent explanation which goes into how to move away from HOCs to hooks. I'm stuck with how to integrate the firebase listener.

I have seen this post which provides a helpful example for how to think about doing this. Not sure if I should be trying to do this in the authListener componentDidMount - or in the Dashboard component that is trying to use it.

NEXT ATTEMPT I found this post, which is trying to solve the same problem.

When I try to implement the solution offered by Shubham Khatri, I set up the firebase config as follows:

A context provider with: import React, {useContext} from 'react'; import Firebase from '../../firebase';

const FirebaseContext = React.createContext(); 

export const FirebaseProvider = (props) => ( 
   <FirebaseContext.Provider value={new Firebase()}> 
      {props.children} 
   </FirebaseContext.Provider> 
); 

The context hook then has:

import React, { useEffect, useContext, useState } from 'react';

const useFirebaseAuthentication = (firebase) => {
    const [authUser, setAuthUser] = useState(null);

    useEffect(() =>{
       const unlisten = 
firebase.auth.onAuthStateChanged(
          authUser => {
            authUser
              ? setAuthUser(authUser)
              : setAuthUser(null);
          },
       );
       return () => {
           unlisten();
       }
    });

    return authUser
}

export default useFirebaseAuthentication;

Then in the index.js I wrap the App in the provider as:

import React from 'react';
import ReactDOM from 'react-dom';
import App from './components/App/Index';
import {FirebaseProvider} from './components/Firebase/ContextHookProvider';

import * as serviceWorker from './serviceWorker';


ReactDOM.render(

    <FirebaseProvider> 
    <App /> 
    </FirebaseProvider>,
    document.getElementById('root')
);

    serviceWorker.unregister();

Then, when I try to use the listener in the component I have:

import React, {useContext} from 'react';
impo

Answer 1

Waitting for answers