React Datepicker( can't get value of input)

问题:

I am new in react. I need use react-datepicker

I want to get value of input, when I change date. If i click on 20th October 2017, i want put 20th October 2017 in my variable. But the main problem that I should work with component, not with input.

Before I just took value from state. Like this.state.value. But right now it is object(Moment) in state. And this object doesn't have value field.

There is my code:

export default class DatePicker extends Component {
constructor (props) {
    super(props);
    // this.props.date should looks like "29 November 2017 00:00"
    // second argument for moment() it is format of date, because RFC 2822 date time format
    this.state = {
        date: moment(this.props.value, 'LLL')
    };
}
handleChange = (date) => {
  // const valueOfInput = this.state.date  <--- I want string with date here
  console.log('this.state.date',this.state.date);
  this.setState({date: date});
};
render() {
    return <Form.Field>
              <Label>
                <Picker
                  selected={this.state.date}
                  onChange={this.handleChange}
                  dateFormat="LLL"
                  locale={this.props.language}
                />
              </Label>
          </Form.Field>

回答1:

Just use this:

handleChange = date => {
  const valueOfInput = date.format();
  ///...
};

Because this datepicker returns a moment.js object!

For more information, look into the moment.js docs here.

回答2:

If you want to get the new value (once the user clicks on a new date from DatePicker) pass the event to the method.

class MyComponent extends React.Component {
  constructor(props) {
    this.state = {inputValue: moment(),} // this will set the initial date to "today", 
                                         // you could also put another prop.state value there
    this.handleChange = this.handleChange.bind(this);
  }
  }


  handleChange(value) {
    console.log(value); // this will be a moment date object
    // now you can put this value into state
    this.setState({inputValue: value});
  }

  render(){
    ...
    <DatePicker 
       onChange={(event) => this.handleChange(event)}
       selected={this.state.inputValue} otherProps={here} />
    ...
  }
};

回答3:

Try this

<DatePicker 
   onChange={(value, e) => this.handleChange(value, e)}
   selected={this.state.inputValue} otherProps={here} />
// you can access the value field in handleChange by e.target.value


handleChange(value, e) {
console.log(value); // this will be a moment date object
console.log(e.target.value); // this will be a string value in datepicker input field

}

回答4:

The new version of react-datepicker library stopped using a moment.js object, so here is my solution if you want to get a formatted string representation of the date.

First import import format from "date-fns/format"; Then

    <DatePicker 
       onChange={(value)=>this.handleChange(format(value, "yyyy/MM/dd", { 
       awareOfUnicodeTokens: true }))}
       dateFormat="yyyy/MM/dd"
       selected={this.state.inputValue} otherProps={here} />
    ...