[英]Cannot read property 'value' of undefined in react project?
Im try to create an Login using react js and firebase. 我尝试使用react js和firebase创建一个Login。 When I try to compile this it gives an error like below
当我尝试编译它时,它给出如下错误
TypeError: Cannot read property 'value' of undefined
It's that I'm try to display user inputs in console. 我试图在控制台中显示用户输入。
My Login.jsx file like below 我的Login.jsx文件如下所示
import React, { Component } from 'react';
class Login extends Component {
constructor(props){
super(props);
this.authWithEmailPassword = this.authWithEmailPassword.bind(this);
}
authWithEmailPassword(event) {
event.preventDefault();
console.log("authed with email");
console.table([{
email: this.emailInput.value,
password: this.passwordInput.value
}])
}
render(){
return(
<div style={loginStyle}>
<hr style={{marginTop: "10px", marginBottom: "10px"}} />
<form onSubmit={(event)=> {this.authWithEmailPassword(event) }}
ref={(form) => { this.loginForm = form }}>
<div style={{ marginBottom: "10px" }} className="pt-callout pt-icon-info-sign">
<h5>Note</h5>
If you dont have an account, this form will create your account
</div>
<label className="pt-label">
Email
<input style={{width: "100%"}} className="pt-input" name="email" type="email"
ref="{(input) => {this.emailInput=input}}" placeholder="Email"/>
</label>
<label className="pt-label">
Password
<input style={{width: "100%"}} className="pt-input" name="password" type="password"
ref="{(input) => {this.passwordInput=input}}" placeholder="Password"/>
</label>
<input type="submit" style={{width: "100%"}} className="pt-button pt-intent-primary" value="Login"/>
</form>
</div>
);
}
}
export default Login;
What did I do wrong Please help me in this matter Im still a newbie. 我做错了什么事,请帮助我。我还是新手。 How can I fix this
我怎样才能解决这个问题
Remove double quotes in ref variable. 删除ref变量中的双引号。 It should be
它应该是
ref={(input) => {this.passwordInput = input}}
Change your refs ref={(input) => this.emailInput = input}
更改您的裁判
ref={(input) => this.emailInput = input}
ref={(input) => this.passwordInput = input}
below is the demo code with your code 下面是带有您的代码的演示代码
For better use cases, use state or props over ref to fetch form data 为了获得更好的用例,请在ref上使用state或props来获取表单数据
reference : use-state-or-refs-in-react-js-form-components 参考: 使用状态或refs-react-js-form-components
change your code with this 改变你的代码
<input style={{width: "100%"}} className="pt-input" name="email" type="email"ref="{(input) => this.emailInput=input}" placeholder="Email"/>
<input style={{width: "100%"}} className="pt-input" name="password" type="password" ref="{(input) => this.passwordInput=input}" placeholder="Password"/>
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