如何在Reactjs中使用Select2？

Question

I have dependent fields like this

    <List>
     <select>
      <option></option>
      <option></option>
     </select>
     <select>
      <option></option>
      <option></option>
     </select>
     <input />
   </List>

If I had 5 <List/> components.How do I add Select2 to each component.I googled online.But couldn't find any working solution.

Code below for react-select .Getting error TypeError: event.target is undefined .

var React = require('react');
var ReactDOM = require('react-dom');
var Select = require('react-select');

var Page = React.createClass({

    getInitialState: function () {
        return {
            firstValue: ''
        }
    },

    handleFirstLevelChange : function (event) {
        this.setState({
            firstValue: event.target.value
        });
    },
    render : function(){

        var options = [
            { value: '', label: 'Select an option' },
            { value: 'one', label: 'One' },
            { value: 'two', label: 'Two' }
        ];

        return (<Select
            value={this.state.firstValue}
            options={options}
            onChange={this.handleFirstLevelChange}
            />)
    }
});

ReactDOM.render(<Page />, document.getElementById('root'));

Answer 1

We are using this wrapper , but there are too many problems around it.

First of all, you can't test code where it is used in NodeJS, because of this issue . Secondly we had problems with initialization of various select2 components via defaultValue parameter. Only one (randomly) of these elements was initalized.

Therefore we going to dump it and replace with react-select soon.

EDIT: We replaced react-select2-wrapper with react-select . It works great for us.

Answer 2

Since you're using React, you'd be better off looking for React components rather than jQuery plugins. You can use for eaxmple react-select , which is pretty similar to Select2.

Answer 3

If you're using refs [docs] , you can access the node via its refs attribute in the componentDidMount function and pass that to select2() :

var Select = React.createClass({
  handleChange: function () {
    this.prop.onChange(
      this.refs.myRef.value
    );
  },

  componentDidMount: function () {
    // Call select2 on your node
    var self = this;
    var node = this.refs.myRef; // or this.refs['myRef']
    $(node)
      .select2({...})
      .on('change', function() {
        // this ensures the change via select2 triggers 
        // the state change for your component 
        self.handleChange();
      });
  },

  render: function () {
    return (
      <select 
        ref="myRef"
        onChange={this.handleChange}>
        // {options}
      </select>
    );
  }
});

I don't believe this is the "React way," but this may help if you don't want to use react-select or some other tool.

Answer 4

If you are just using jquery and select2 in a react application, you can simply link the cdn for Jquery and select2 in public/index.html inside "head" tag. Then in your src/components/component.js. You can use jquery select2 like this:

 constructor(props) { super(props); this.state = { Provinces: [], }; this.select2PX = this.select2PX.bind(this); // this.ApiTest = this.ApiTest.bind(this); } select2PX(){ window.$(document).ready(function() { window.$('#phuong-xa').select2(); }); } componentDidMount(){ this.select2PX(); } render(){ return (.... html); } 

Because you use the cdns in the public/.html file, you need to use window.$ to use jquery. It achieves the same thing as using select2 in a html file.

Answer 5

Simple wrapper.

Add select2 js + css on index.html, write wrapper over select input

function renderOptions(option_items) {
    if(option_items) {
        return Object.entries(option_items).map(function (item) {
            return <option key={item[0]} value={item[0]}>{item[1]}</option>
        })
    }
}

class Select2Input extends Component {

    constructor(props) {
        super(props)
        this.ref_input = React.createRef()
    }

    /**
    * Add select2 bind and send onChange manually
    */
    componentDidMount() {
        const self = this

        $(self.ref_input.current).select2({
            tags: true,
        }).on('change', function(event) {
            var value = $(event.currentTarget).val()
            if(self.props.multiple === true) {
                value = List(value)
            }
            self.props.onChange(self.props.name, value)
        })
    }

    /**
    * Emit change event for reload select2 if options has change
    */
    componentDidUpdate(prevProps) {
        if(prevProps.option_items !== this.props.option_items) {
            $(this.ref_input.current).change()
        }
    }

    render() {
        return <select className="form-control"
                    multiple={this.props.multiple}
                    name={this.props.name}
                    value={this.props.value}
                    disabled={this.props.disabled}
                    ref={this.ref_input}>
                            {renderOptions(this.props.option_items)}
            </select>
    }
}