form-consumer.jsx

export class MyUserForm extends Component {
  constructor() {
    this.state = { myFormData: {} };
  }

  render() {
    const { myFormData } = this.state;
    return (
      <MagicForm onChange={data => this.setState({ myFormData: data })}>
        <Input type="text" name="fieldName" value={myFormData.fieldName} />
      </MagicForm>
    );
  }
}