我在渲染函数中有一个简单的表单,如下所示:
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
},
handleLogin: function() {
//How to access email and password here ?
}
我应该在我的handleLogin: function(){…}访问电子邮件和密码字段?
迈克尔·肖克的回答是:
class MyForm extends React.Component {
constructor() {
super();
this.handleSubmit = this.handleSubmit.bind(this);
}
handleSubmit(event) {
event.preventDefault();
const data = new FormData(event.target);
console.log(data.get('email')); // reference by form input's `name` tag
fetch('/api/form-submit-url', {
method: 'POST',
body: data,
});
}
render() {
return (
<form onSubmit={this.handleSubmit}>
<label htmlFor="username">Enter username</label>
<input id="username" name="username" type="text" />
<label htmlFor="email">Enter your email</label>
<input id="email" name="email" type="email" />
<label htmlFor="birthdate">Enter your birth date</label>
<input id="birthdate" name="birthdate" type="text" />
<button>Send data!</button>
</form>
);
}
}
参见这篇Medium文章:如何用Just React处理表单
此方法仅在按下提交按钮时获取表单数据。我觉得干净多了!
这是一个动态添加字段的示例。在这里,表单数据将使用React useState钩子通过输入名称键存储。
import React, { useState } from 'react'
function AuthForm({ firebase }) {
const [formData, setFormData] = useState({});
// On Form Submit
const onFormSubmit = (event) => {
event.preventDefault();
console.log('data', formData)
// Submit here
};
// get Data
const getData = (key) => {
return formData.hasOwnProperty(key) ? formData[key] : '';
};
// Set data
const setData = (key, value) => {
return setFormData({ ...formData, [key]: value });
};
console.log('firebase', firebase)
return (
<div className="wpcwv-authPage">
<form onSubmit={onFormSubmit} className="wpcwv-authForm">
<input name="name" type="text" className="wpcwv-input" placeholder="Your Name" value={getData('name')} onChange={(e) => setData('name', e.target.value)} />
<input name="email" type="email" className="wpcwv-input" placeholder="Your Email" value={getData('email')} onChange={(e) => setData('email', e.target.value)} />
<button type="submit" className="wpcwv-button wpcwv-buttonPrimary">Submit</button>
</form>
</div>
)
}
export default AuthForm
使用输入中的change事件来更新组件的状态,并在handllogin中访问它:
handleEmailChange: function(e) {
this.setState({email: e.target.value});
},
handlePasswordChange: function(e) {
this.setState({password: e.target.value});
},
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleEmailChange} />
<input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handlePasswordChange}/>
<button type="button" onClick={this.handleLogin}>Login</button>
</form>);
},
handleLogin: function() {
console.log("EMail: " + this.state.email);
console.log("Password: " + this.state.password);
}
工作小提琴。
此外,阅读文档,有一个完整的部分专门用于表单处理:表单
以前你也可以使用React的双向数据绑定助手mixin来实现同样的事情,但现在它被弃用了,取而代之的是设置值和更改处理程序(如上所述):
var ExampleForm = React.createClass({
mixins: [React.addons.LinkedStateMixin],
getInitialState: function() {
return {email: '', password: ''};
},
handleLogin: function() {
console.log("EMail: " + this.state.email);
console.log("Password: " + this.state.password);
},
render: function() {
return (
<form>
<input type="text" valueLink={this.linkState('email')} />
<input type="password" valueLink={this.linkState('password')} />
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
}
});
文档在这里:双向绑定助手。
如果元素名多次出现,则必须使用forEach()。
html
<input type="checkbox" name="delete" id="flizzit" />
<input type="checkbox" name="delete" id="floo" />
<input type="checkbox" name="delete" id="flum" />
<input type="submit" value="Save" onClick={evt => saveAction(evt)}></input>
js
const submitAction = (evt) => {
evt.preventDefault();
const dels = evt.target.parentElement.delete;
const deleted = [];
dels.forEach((d) => { if (d.checked) deleted.push(d.id); });
window.alert(deleted.length);
};
注意,本例中的dels是RadioNodeList,而不是数组,也不是Iterable。forEach()是列表类的内置方法。这里不能使用map()或reduce()。
同样,这个也可以用。
handleChange: function(state,e) {
this.setState({[state]: e.target.value});
},
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleChange.bind(this, 'email')} />
<input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handleChange.bind(this, 'password')}/>
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
},
handleLogin: function() {
console.log("EMail: ", this.state.email);
console.log("Password: ", this.state.password);
}