react checkbox indeterminate

indeterminate.js

// https://davidwalsh.name/react-indeterminate
// To add the indeterminate property to the checkbox, I needed to take advantage of the ref attribute:

const { value, checked, indeterminate } = this.props

return render(
    <input
        type="checkbox"
        value={value}
        checked={checked}
        ref={el => el && (el.indeterminate = indeterminate)}
    />
)

// https://stackoverflow.com/a/52859693/2845262
ReactDOM.render(
  <label>
    <input
      type="checkbox"
      ref={input => {
        if (input) {
          input.indeterminate = true;
        }
      }}
    />
    {' '}
    Un test
  </label>,
  document.getElementById('root')
);