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?


当前回答

我建议采取以下方法:

import {Autobind} from 'es-decorators';

export class Form extends Component {

    @Autobind
    handleChange(e) {
        this.setState({[e.target.name]: e.target.value});
    }

    @Autobind
    add(e) {
        e.preventDefault();
        this.collection.add(this.state);
        this.refs.form.reset();
    }

    shouldComponentUpdate() {
        return false;
    }

    render() {
        return (
            <form onSubmit={this.add} ref="form">
                <input type="text" name="desination" onChange={this.handleChange}/>
                <input type="date" name="startDate" onChange={this.handleChange}/>
                <input type="date" name="endDate" onChange={this.handleChange}/>
                <textarea name="description" onChange={this.handleChange}/>
                <button type="submit">Add</button>
            </form>
        )
    }

}

其他回答

我像这样使用React Component state:

<input type="text" name='value' value={this.state.value} onChange={(e) => this.handleChange(e)} />

handleChange(e){
   this.setState({[e.target.name]: e.target.value})
}`

我建议采取以下方法:

import {Autobind} from 'es-decorators';

export class Form extends Component {

    @Autobind
    handleChange(e) {
        this.setState({[e.target.name]: e.target.value});
    }

    @Autobind
    add(e) {
        e.preventDefault();
        this.collection.add(this.state);
        this.refs.form.reset();
    }

    shouldComponentUpdate() {
        return false;
    }

    render() {
        return (
            <form onSubmit={this.add} ref="form">
                <input type="text" name="desination" onChange={this.handleChange}/>
                <input type="date" name="startDate" onChange={this.handleChange}/>
                <input type="date" name="endDate" onChange={this.handleChange}/>
                <textarea name="description" onChange={this.handleChange}/>
                <button type="submit">Add</button>
            </form>
        )
    }

}

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!

另一种方法是使用ref属性并使用this.refs引用值。这里有一个简单的例子:

render: function() {
    return (<form onSubmit={this.submitForm}>
        <input ref="theInput" />
    </form>);
},
submitForm: function(e) {
    e.preventDefault();
    alert(React.findDOMNode(this.refs.theInput).value);
}

更多信息可以在React文档中找到: https://facebook.github.io/react/docs/more-about-refs.html#the-ref-string-attribute

关于如何在React中使用单选按钮中描述的很多原因?这种方法并不总是最好的,但在一些简单的情况下确实是一种有用的替代方法。

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。