Get the value of checkbox using ref in React

Question

is there any way to get value of checkbox using ref in React. Normal way return always value "on" to me.

var MyForm = React.createClass({
    save: function(){
        console.log(this.refs.check_me.value);
    },

    render: function(){
        return <div><h1>MyForm</h1>
            <div className="checkbox">
                <label>
                    <input type="checkbox" ref="check_me" /> Check me out
                </label>
            </div>
            <button className="btn btn-default" onClick={this.save}>Submit</button>
        </div>
    }
});

Answer 1

For checkbox, use "checked" instead of "value":

var MyForm = React.createClass({
  save: function () {
    console.log(this.refs.check_me.checked);
  },

  render: function () {
    return <div><h1>MyForm</h1>
      <div className="checkbox">
        <label>
          <input type="checkbox" ref="check_me" /> Check me out
        </label>
      </div>
      <button className="btn btn-default" onClick={this.save}>Submit</button>
    </div>
  }
});

As a result:

Answer 2

There is a classic way to catch the event and corresponding values with the help of:

event.target.checked, event.target.name

You can see an example:

class MyForm extends React.Component {
    onChangeFavorite(event){
        console.log(event.target.checked, event.target.name);
    };
    render(){
        return (<div><h1>MyForm</h1>
            <div className="checkbox">
                <label>
                   <input type="checkbox" name="myCheckBox1" 
                     onChange={this.onChangeFavorite} 
                     defaultChecked={false} /> 
                   Check me out
                </label>
            </div>
            <button className="btn btn-default" onClick={this.save}>Submit</button>
        </div>)
    };
};

Answer 3

You can make the checkbox a controlled element by listening to onChange and giving it a state value. Try the following:

var MyForm = React.createClass({
  save: function(){
    console.log(this.refs.check_me.value);
  },

  toggleCheckboxValue: () => {
    this.setState({checkBoxValue: !this.state.checkboxValue});
  },

  render: function(){
    return <div><h1>MyForm</h1>
        <div className="checkbox">
            <label>
                <input type="checkbox" ref="check_me" value={this.state.checkboxValue} onChange={this.toggleCheckboxValue} /> Check me out
            </label>
        </div>
        <button className="btn btn-default" onClick={this.save}>Submit</button>
    </div>
  }
});

whenever the checkbox is clicked it will run the toggleCheckboxValue function, which will toggle the value of this.state.checkboxValue.

Just don't forget to initialize the this.state.checkboxValue function in your code.

Note: As ivarni pointed out, you may want to control the checked value specifically for checkboxes rather than value. Though both solutions will work.