static-cms/src/backends/test-repo/AuthenticationPage.js

import React from 'react';

export default class AuthenticationPage extends React.Component {
  static propTypes = {
    onLogin: React.PropTypes.func.isRequired
  };

  state = { email: '' };

  handleLogin = e => {
    e.preventDefault();
    this.props.onLogin(this.state);
  };

  handleEmailChange = e => {
    this.setState({ email: e.target.value });
  };

  render() {
    return <form onSubmit={this.handleLogin}>
      <p>
        <label>Your name or email: <input type='text' onChange={this.handleEmailChange}/></label>
      </p>
      <p>
        <button type='submit'>Login</button>
      </p>
    </form>;
  }
}