delivery-form.js

import React from 'react';
import {reduxForm, Field, SubmissionError} from 'redux-form';
import Input from './input';
import {required, nonEmpty, exactLength, onlyNumbers} from './validators';
const exactLength5 = exactLength(5);

const API_BASE_URL =
    process.env.REACT_APP_API_BASE_URL || 'http://localhost:8080/api';

export class DeliveryForm extends React.Component {
    onSubmit(values) {
        return fetch(`${API_BASE_URL}/report`, {
            method: 'POST',
            body: JSON.stringify(values),
            headers: {
                'Content-Type': 'application/json'
            }
        })
            .then(res => {
                if (!res.ok) {
                    if (
                        res.headers.has('content-type') &&
                        res.headers
                            .get('content-type')
                            .startsWith('application/json')
                    ) {
                        // It's a nice JSON error returned by us, so decode it
                        return res.json().then(err => Promise.reject(err));
                    }
                    // It's a less informative error returned by express
                    return Promise.reject({
                        code: res.status,
                        message: res.statusText
                    });
                }
                return;
            })
            .then(() => console.log('Submitted with values', values))
            .catch(err => {
                const {reason, message, location} = err;
                if (reason === 'ValidationError') {
                    // Convert ValidationErrors into SubmissionErrors for Redux Form
                    return Promise.reject(
                        new SubmissionError({
                            [location]: message
                        })
                    );
                }
                return Promise.reject(
                    new SubmissionError({
                        _error: message
                    })
                );
            });
    }

    render() {
        let successMessage;
        if (this.props.submitSucceeded) {
            successMessage = (
                <div className="message message-success">
                    Report submitted successfully
                </div>
            );
        }

        let errorMessage;
        if (this.props.error) {
            errorMessage = (
                <div className="message message-error">{this.props.error}</div>
            );
        }

        return (
            <div className="delivery-form">
                <h2>Report a problem with your delivery</h2>
                <form
                    onSubmit={this.props.handleSubmit(values =>
                        this.onSubmit(values)
                    )}>
                    {successMessage}
                    {errorMessage}
                    <Field
                        name="trackingNumber"
                        id="trackingNumber"
                        label="Tracking number"
                        component={Input}
                        validate={[
                            required,
                            nonEmpty,
                            exactLength5,
                            onlyNumbers
                        ]}
                    />
                    <Field
                        name="issue"
                        id="issue"
                        label="What is your issue?"
                        component={Input}
                        element="select">
                        <option value="not-delivered">
                            My delivery hasn't arrived
                        </option>
                        <option value="wrong-item">
                            The wrong item was delivered
                        </option>
                        <option value="missing-part">
                            Part of my order was missing
                        </option>
                        <option value="damaged">
                            Some of my order arrived damaged
                        </option>
                        <option value="other">
                            Other (give details below)
                        </option>
                    </Field>
                    <Field
                        name="details"
                        id="details"
                        label="Give more details (optional)"
                        component={Input}
                        element="textarea"
                    />
                    <button type="submit">Submit</button>
                </form>
            </div>
        );
    }
}

export default reduxForm({
    form: 'delivery',
    initialValues: {
        issue: 'not-delivered'
    }
})(DeliveryForm);

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import {Provider} from 'react-redux';
import './index.css';
import store from './store';
import DeliveryForm from './delivery-form';
import registerServiceWorker from './registerServiceWorker';

ReactDOM.render(
    <Provider store={store}>
        <DeliveryForm />
    </Provider>,
    document.getElementById('root')
);
registerServiceWorker();

input.js

import React from 'react';

export default class Input extends React.Component {
    componentDidUpdate(prevProps) {
        if (!prevProps.meta.active && this.props.meta.active) {
            this.input.focus();
        }
    }
    render() {
        const Element = this.props.element || 'input';

        let error;
        if (this.props.meta.touched && this.props.meta.error) {
            error = <div className="form-error">{this.props.meta.error}</div>;
        }

        let warning;
        if (this.props.meta.touched && this.props.meta.warning) {
            warning = (
                <div className="form-warning">{this.props.meta.warning}</div>
            );
        }

        return (
            <div className="form-input">
                <label htmlFor={this.props.input.name}>
                    {this.props.label}
                    {error}
                    {warning}
                </label>
                <Element
                    {...this.props.input}
                    id={this.props.input.name}
                    type={this.props.type}
                    ref={input => (this.input = input)}>
                    {this.props.children}
                </Element>
            </div>
        );
    }
}

registerServiceWorker.js

// In production, we register a service worker to serve assets from local cache.

// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on the "N+1" visit to a page, since previously
// cached resources are updated in the background.

// To learn more about the benefits of this model, read https://goo.gl/KwvDNy.
// This link also includes instructions on opting out of this behavior.

const isLocalhost = Boolean(
  window.location.hostname === 'localhost' ||
    // [::1] is the IPv6 localhost address.
    window.location.hostname === '[::1]' ||
    // 127.0.0.1/8 is considered localhost for IPv4.
    window.location.hostname.match(
      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
    )
);

export default function register() {
  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
    // The URL constructor is available in all browsers that support SW.
    const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
    if (publicUrl.origin !== window.location.origin) {
      // Our service worker won't work if PUBLIC_URL is on a different origin
      // from what our page is served on. This might happen if a CDN is used to
      // serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
      return;
    }

    window.addEventListener('load', () => {
      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

      if (isLocalhost) {
        // This is running on localhost. Lets check if a service worker still exists or not.
        checkValidServiceWorker(swUrl);

        // Add some additional logging to localhost, pointing developers to the
        // service worker/PWA documentation.
        navigator.serviceWorker.ready.then(() => {
          console.log(
            'This web app is being served cache-first by a service ' +
              'worker. To learn more, visit https://goo.gl/SC7cgQ'
          );
        });
      } else {
        // Is not local host. Just register service worker
        registerValidSW(swUrl);
      }
    });
  }
}

function registerValidSW(swUrl) {
  navigator.serviceWorker
    .register(swUrl)
    .then(registration => {
      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        installingWorker.onstatechange = () => {
          if (installingWorker.state === 'installed') {
            if (navigator.serviceWorker.controller) {
              // At this point, the old content will have been purged and
              // the fresh content will have been added to the cache.
              // It's the perfect time to display a "New content is
              // available; please refresh." message in your web app.
              console.log('New content is available; please refresh.');
            } else {
              // At this point, everything has been precached.
              // It's the perfect time to display a
              // "Content is cached for offline use." message.
              console.log('Content is cached for offline use.');
            }
          }
        };
      };
    })
    .catch(error => {
      console.error('Error during service worker registration:', error);
    });
}

function checkValidServiceWorker(swUrl) {
  // Check if the service worker can be found. If it can't reload the page.
  fetch(swUrl)
    .then(response => {
      // Ensure service worker exists, and that we really are getting a JS file.
      if (
        response.status === 404 ||
        response.headers.get('content-type').indexOf('javascript') === -1
      ) {
        // No service worker found. Probably a different app. Reload the page.
        navigator.serviceWorker.ready.then(registration => {
          registration.unregister().then(() => {
            window.location.reload();
          });
        });
      } else {
        // Service worker found. Proceed as normal.
        registerValidSW(swUrl);
      }
    })
    .catch(() => {
      console.log(
        'No internet connection found. App is running in offline mode.'
      );
    });
}

export function unregister() {
  if ('serviceWorker' in navigator) {
    navigator.serviceWorker.ready.then(registration => {
      registration.unregister();
    });
  }
}

store.js

import {createStore, combineReducers} from 'redux';
import {reducer as formReducer} from 'redux-form';

export default createStore(
    combineReducers({
        form: formReducer
    })
);

validators.js

export const required = value => (value ? undefined : 'Required');
export const nonEmpty = value =>
    value.trim() !== '' ? undefined : 'Cannot be empty';
export const exactLength = length => value =>
    value.length === length
        ? undefined
        : `Must contain exactly ${length} characters`;
export const onlyNumbers = value =>
    /^\d+$/.test(value) ? undefined : 'Must only contain numbers';