Javascript 全局变量在函数中重新初始化后返回null
我正在开发react应用程序，并使用回调函数将一个值从子组件提升到父组件。现在，当我试图通过执行以下操作将值从回调函数检索到全局变量时 这是父组件Javascript 全局变量在函数中重新初始化后返回null,javascript,reactjs,variables,callback,Javascript,Reactjs,Variables,Callback,我正在开发react应用程序，并使用回调函数将一个值从子组件提升到父组件。现在，当我试图通过执行以下操作将值从回调函数检索到全局变量时 这是父组件 import React , {Component} from 'react'; import SignIn from './SignIn' import About from './WebPageFour' import SimpleModal from './Modal' import {BrowserRouter as Router,Route
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React，{Component}来自'React'；
从“./登录”导入登录
从“/WebPageFour”导入关于
从“./Modal”导入SimpleModel
从“react Router dom”导入{BrowserRouter as Router，Route，Switch}
从“./头”导入头；
从“/Global”导入{isvisted}；
从“./Banner”导入横幅
var user=null
常量回调=（isSignedIn）=>{
用户=isSignedIn
//console.log（用户）
返回用户
}
console.log（用户）
类主扩展组件{
建造师（道具）{
超级（道具）
this.visit\u checked=this.visit\u checked.bind（this）；
这个州={
计数：0，
伊斯莫达洛彭：错，
伊西涅丁：错
}
}
render（）{
返回(
{/*材质ui导航栏*/}
{/*页的路由*/}
(
)}
/>
);
}
}
导出默认值（主）；
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
//导入FirebaseAuth和firebase。
从“React”导入React；
从“react firebaseui/StyledFirebaseAuth”导入StyledFirebaseAuth；
导入“firebase/auth”；
从“firebase”导入firebase；
从“@material ui/core”导入{Grid、Card、排版、CardContent、CardActions、TextField、Button、Box}
//从“../helpers/Firebase”导入{auth}
类签名扩展了React.Component{
//组件的本地状态。
状态={
isSignedIn:false，//本地已登录状态。
电子邮件：“”，
密码：“”
};
//配置FirebaseUI。
uiConfig={
//弹出签名流，而不是重定向流。
signInFlow:“弹出窗口”，
//我们将显示谷歌和Facebook作为身份验证提供商。
签署：[
firebase.auth.GoogleAuthProvider.PROVIDER\u ID，
firebase.auth.FacebookAuthProvider.PROVIDER\u ID
],
回调：{
//避免在登录后重定向。
SignInsessWithAuthResult:（）=>false
}
};
//收听Firebase身份验证状态并设置本地状态。
componentDidMount（）{
this.unregisterAuthObserver=firebase.auth（）.onAuthStateChanged(
（user）=>this.setState（{isSignedIn:！！user}）
);
}
//确保在组件卸载时取消注册Firebase观察员。
组件将卸载（）{
这是。取消注册AuthObserver（）；
}
handleChange=（e）=>{
这是我的国家({
[e.target.name]：e.target.value
})
}
handleSubmit（e）{
e、 预防默认值（）
firebase.auth（）.signiWithEmailandPassword（this.state.email，this.state.password）。catch（函数（错误）{
//在这里处理错误。
var errorCode=error.code；
var errorMessage=error.message；
console.log（'errors'+errorCode+'error'+errorMessage）
// ...
})
}
render（）{
**this.props.callBack（this.state.isSignedIn）**
如果（！this.state.isSignedIn）{
返回(
this.handleSubmit（values）}>
登录
登录
);
}
返回(
我的应用程序
欢迎{this.state.email}！您现在已登录
firebase.auth（）.signOut（）}color=“primary”>注销
);
}
}
导出默认签名
函数内的console.log返回所需的值，但函数外的console.log返回null您声明了回调函数，但没有调用它 试试这个
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
callback(boolean)
console.log(user)
下面是父组件
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React，{Component}来自'React'；
从“./登录”导入登录
从“/WebPageFour”导入关于
从“./Modal”导入SimpleModel
从“react Router dom”导入{BrowserRouter as Router，Route，Switch}
从“./头”导入头；
从“/Global”导入{isvisted}；
从“./Banner”导入横幅
var user=null
常量回调=（isSignedIn）=>{
用户=isSignedIn
//console.log（用户）
返回用户
}
console.log（用户）
类主扩展组件{
建造师（道具）{
超级（道具）
this.visit\u checked=this.visit\u checked.bind（this）；
这个州={
计数：0，
伊斯莫达洛彭：错，
伊西涅丁：错
}
}
render（）{
返回(
{/*材质ui导航栏*/}
{/*页的路由*/}
(
)}
/>
);
}
}
导出默认值（主）；
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
import React , {Component} from 'react';
import SignIn from './SignIn'
import About from './WebPageFour'
import SimpleModal from './Modal'
import {BrowserRouter as Router,Route,Switch} from 'react-router-dom'
import Header from './Header';
import {isVisited} from './Global';
import Banner from './Banner'
var user = null
const callBack=(isSignedIn)=>{
user = isSignedIn
// console.log(user)
return user
}
console.log(user)
class Main extends Component {
constructor(props){
super(props)
this.visit_checked=this.visit_checked.bind(this);
this.state={
count: 0,
isModalOpen:false,
isSignedIn:false
}
}
render() {
return(
<>
{/* material-ui navbar */}
<Header/>
<Banner/>
{/* routes for pages */}
<Route path="/SignIn" render={()=>(
<React.Fragment>
<SignIn callBack={callBack}/>
</React.Fragment>
)}
/>
</Switch>
</>
);
}
}
export default (Main);
// Import FirebaseAuth and firebase.
import React from 'react';
import StyledFirebaseAuth from 'react-firebaseui/StyledFirebaseAuth';
import 'firebase/auth';
import firebase from 'firebase';
import {Grid, Card, Typography, CardContent, CardActions, TextField, Button, Box} from '@material-ui/core'
// import {auth} from '../helpers/Firebase'
class SignIn extends React.Component {
// The component's Local state.
state = {
isSignedIn: false, // Local signed-in state.
email: '',
password:''
};
// Configure FirebaseUI.
uiConfig = {
// Popup signin flow rather than redirect flow.
signInFlow: 'popup',
// We will display Google and Facebook as auth providers.
signInOptions: [
firebase.auth.GoogleAuthProvider.PROVIDER_ID,
firebase.auth.FacebookAuthProvider.PROVIDER_ID
],
callbacks: {
// Avoid redirects after sign-in.
signInSuccessWithAuthResult: () => false
}
};
// Listen to the Firebase Auth state and set the local state.
componentDidMount() {
this.unregisterAuthObserver = firebase.auth().onAuthStateChanged(
(user) => this.setState({isSignedIn: !!user})
);
}
// Make sure we un-register Firebase observers when the component unmounts.
componentWillUnmount() {
this.unregisterAuthObserver();
}
handleChange=(e)=>{
this.setState({
[e.target.name]:e.target.value
})
}
handleSubmit(e){
e.preventDefault()
firebase.auth().signInWithEmailAndPassword(this.state.email, this.state.password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
console.log('errors'+errorCode+' error '+errorMessage)
// ...
})
}
render() {
**this.props.callBack(this.state.isSignedIn)**
if (!this.state.isSignedIn) {
return (
<React.Fragment>
<div style={{position:'relative'}}>
<Box mt={5}>
<Grid item container justify="center" xs={12} md={12} lg={12}>
<Card info={this.info}>
<form onSubmit={(values) => this.handleSubmit(values)}>
<CardActions>
<CardContent>
<Box mt={2} mb={4}>
<Typography variant="h5" className="text-capitalize text-center">sign in</Typography>
</Box>
<Box mb={2}>
<TextField label="email" variant="outlined" name="email" size="small" onChange={this.handleChange} /><br/>
</Box>
<Box>
<TextField type="password" name="password" label="password" variant="outlined" size="small" onChange={this.handleChange} />
</Box>
</CardContent>
</CardActions>
<CardActions>
<Box ml={2} mb={2} mt={0} pl={8}>
<Button
type="submit"
value="submit"
variant="contained"
color="primary"
size="small"
className="text-capitalize"
>sign in</Button>
</Box>
</CardActions>
</form>
<br/>
<hr/>
<br/>
<StyledFirebaseAuth uiConfig={this.uiConfig} firebaseAuth={firebase.auth()}/>
</Card>
</Grid>
</Box>
</div>
</React.Fragment>
);
}
return (
<div>
<Grid container justify="center">
<Grid item className="bg-color" xs={12}>
<h2 style={{textAlign:'center'}}>My App</h2>
</Grid>
<Grid item xs={12} md={8} lg={5} >
<br/>
<p>Welcome {this.state.email} ! You are now signed-in!</p>
<Button onClick={() => firebase.auth().signOut()} color="primary">Sign-out</Button>
</Grid>
</Grid>
</div>
);
}
}
export default SignIn
//导入FirebaseAuth和firebase。
从“React”导入React；
从“react firebaseui/StyledFirebaseAuth”导入StyledFirebaseAuth；
导入“firebase/auth”；
从“firebase”导入firebase；
从“@material ui/core”导入{Grid、Card、排版、CardContent、CardActions、TextField、Button、Box}
//从“../h”导入{auth}