Go 언어 Front End 제작해보기(로그인 페이지) 4장

◆  로그인 페이지

    ▶로그인 폼을 작성 – src/modalwindow.js 파일

class SingInForm extends React.Component {
    constructor(props) {
        super(props);
        this.handleChange = this.handleChange.bind(this);
        this.handleSubmit = this.handleSubmit.bind(this);
        this.state = {
            errormessage: ''
        }
    }

    handleChange(event) {
        const name = event.target.name;
        const value = event.target.value;
        this.setState({
            [name]: value
        });
    }

    handleSubmit(event) {
        event.preventDefault();
        console.log(JSON.stringify(this.state));
    }

    render() {
        let message = null;
        if (this.state.errormessage.length !== 0) {
            message = <h5 className="mb-4 text-danger">{this.state.errormessage}</h5>;
        }

        return (
            <div>
                {message}
                <form onSubmit={this.handleSubmit}>
                    <h5 className="mb-4">Basic Info</h5>
                    <div className="form-group">
                        <label htmlFor="email">Email:</label>
                        <input name="email" type="email" className="form-control" id="email"  onChange={this.handleChange}/>
                    </div>
                    <div className="form-group">
                        <label htmlFor="pass">Password:</label>
                        <input name="password" type="password" className="form-control" id="pass" onChange={this.handleChange} />
                    </div>
                    <div className="form-row text-center">
                        <div className="col-12 mt-2">
                            <button type="submit" className="btn btn-success btn-large">Sign In</button>
                        </div>
                        <div className="col-12 mt-2">
                            <button type="submit" className="btn btn-link text-info" onClick={() => this.props.handleNewUser()}> New User? Register</button>
                        </div>
                    </div>
                </form>
            </div>
        );
    }
}

---

◆ 로그인 했을 경우 보여질 탐색 메뉴

    ▶ Navigation.js 파일 수정

import React from 'react';
import { NavLink } from 'react-router-dom';

export default class Navigation extends React.Component {

    buildLoggedInMenu() {
        return (
            <div className="navbar-brand order-1 text-white my-auto">
                <div className="btn-group">
                    <button type="button" className="btn btn-success dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                        Welcome {this.props.user.name}
                    </button>
                    <div className="dropdown-menu">
                        <a className="btn dropdown-item" role="button">Sign Out</a>
                    </div>
                </div>
            </div>
        );
    }
    render() {
        return (
            <div>
                <nav className="navbar navbar-expand-lg navbar-dark bg-success fixed-top">
                    <div className="container">
                        {
                            this.props.user.loggedin ?
                                /*<p className="navbar-brand order-1 text-white my-auto">Welcome {this.props.user.name}</p>*/
                                this.buildLoggedInMenu()
                                : <button type="button" className="navbar-brand order-1 btn btn-success"  onClick={() => { this.props.showModalWindow();}}>Sign in</button>
                        }
                        <div className="navbar-collapse" id="navbarNavAltMarkup">
                            <div className="navbar-nav">
                                <NavLink className="nav-item nav-link" to="/">Home</NavLink>
                                <NavLink className="nav-item nav-link" to="/promos">Promotions</NavLink>
                                {this.props.user.loggedin ? <NavLink className="nav-item nav-link" to="/myorders">My Orders</NavLink> : null}
                                <NavLink className="nav-item nav-link" to="/about">About</NavLink>
                            </div>
                        </div>
                    </div>
                </nav>
            </div>
        );
    }
}

◆ 서비스 등록을 위한 페이지 작성

    ▶ src/registerServiceWorker.js 파일을 생성하고 작성

// 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();
    });
  }
}
    .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();
    });
  }
}