React로 만든 앱에 PWA 적용하기

PWA란?

프로그레시브 웹 앱 (Progressive Web App)의 약자.

HTML, CSS, JavaScript와 같은 웹 기술로 만드는 앱

 

네이티브 앱을 개발하는 것보다 훨씬 빠르게 개발할 수 있고, 푸시 알림, 오프라인 지원같은 네이티브 앱의 특징도 제공

 

 

PWA로 만든 앱

트위터

스타벅스

핀터레스트

우버

 

 

React with PWA 만드는 방법

npx create-react-app my-app --template cra-template-pwa

 

이렇게 리액트 앱을 제작하기 앞서서 PWA를 함께 적용하는 create app 명령을 내릴 수 있다.

 

하지만 나는 이미 다 만들어진 react 앱을 PWA로 만들고 싶었기 때문에 수동으로 설정을 해 주었다.

 

 

manifest.json

React 프로젝트의 public 폴더 내부에 CRA로 생성되어 있던 manifest.json을 다음과 같이 수정한다.

{
    "name": "Colordentity",
    "short_name": "Colordentity",
    "description": "퍼스널 컬러 측정 앱입니다.",
    "scope": ".",
    "start_url": "./",
    "display": "fullscreen",
    "orientation": "portrait",
    "theme_color": "#ffffff",
    "background_color": "#ffffff",
    "icons": [
      {
        "src": "icons/iconx128.png",
        "sizes": "128x128",
        "type": "image/png"
      },
      {
        "src": "icons/iconx192.png",
        "sizes": "192x192",
        "type": "image/png"
      },
      {
        "src": "icons/iconx384.png",
        "sizes": "384x384",
        "type": "image/png"
      },
      {
        "src": "icons/iconx512.png",
        "sizes": "512x512",
        "type": "image/png"
      }
    ]
  }

여기서 icon은 직접 만들 수 있는데 해당 사이트를 통해 손쉽게 제작이 가능하다.

 

아이콘 만드는 사이트

https://maskable.app/editor

 

icon 제작

 

 

 

manifest.json 작성이 완료되면 개발자도구 > Application 탭의 Manifest 를 클릭하면 다음과 같은 화면이 나타난다.

 

service-worker.js

src 폴더 내부에 service-worker.js 파일을 추가한다.

 

서비스 워커란 브라우저가 백그라운드에서 실행하는 웹페이지와는 별개로 작동하는 스크립트로, 오프라인 환경에서 캐시(cache)와의 상호작용, 백그라운드 동기화, 푸시 알림 등의 기능을 가능하게 만들어 준다.

 

/* eslint-disable no-restricted-globals */

// This service worker can be customized!
// See https://developers.google.com/web/tools/workbox/modules
// for the list of available Workbox modules, or add any other
// code you'd like.
// You can also remove this file if you'd prefer not to use a
// service worker, and the Workbox build step will be skipped.

import { clientsClaim } from 'workbox-core';
import { ExpirationPlugin } from 'workbox-expiration';
import { precacheAndRoute, createHandlerBoundToURL } from 'workbox-precaching';
import { registerRoute } from 'workbox-routing';
import { StaleWhileRevalidate } from 'workbox-strategies';

clientsClaim();

// Precache all of the assets generated by your build process.
// Their URLs are injected into the manifest variable below.
// This variable must be present somewhere in your service worker file,
// even if you decide not to use precaching. See https://cra.link/PWA
precacheAndRoute(self.__WB_MANIFEST);

// Set up App Shell-style routing, so that all navigation requests
// are fulfilled with your index.html shell. Learn more at
// https://developers.google.com/web/fundamentals/architecture/app-shell
const fileExtensionRegexp = new RegExp('/[^/?]+\\.[^/]+$');
registerRoute(
  // Return false to exempt requests from being fulfilled by index.html.
  ({ request, url }) => {
    // If this isn't a navigation, skip.
    if (request.mode !== 'navigate') {
      return false;
    } // If this is a URL that starts with /_, skip.

    if (url.pathname.startsWith('/_')) {
      return false;
    } // If this looks like a URL for a resource, because it contains // a file extension, skip.

    if (url.pathname.match(fileExtensionRegexp)) {
      return false;
    } // Return true to signal that we want to use the handler.

    return true;
  },
  createHandlerBoundToURL(process.env.PUBLIC_URL + '/index.html')
);

// An example runtime caching route for requests that aren't handled by the
// precache, in this case same-origin .png requests like those from in public/
registerRoute(
  // Add in any other file extensions or routing criteria as needed.
  ({ url }) => url.origin === self.location.origin && url.pathname.endsWith('.png'), // Customize this strategy as needed, e.g., by changing to CacheFirst.
  new StaleWhileRevalidate({
    cacheName: 'images',
    plugins: [
      // Ensure that once this runtime cache reaches a maximum size the
      // least-recently used images are removed.
      new ExpirationPlugin({ maxEntries: 50 }),
    ],
  })
);

// This allows the web app to trigger skipWaiting via
// registration.waiting.postMessage({type: 'SKIP_WAITING'})
self.addEventListener('message', (event) => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});

// Any other custom service worker logic can go here.

 

serviceWorkerRegistration.js

// This optional code is used to register a service worker.
// register() is not called by default.

// 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 subsequent visits to a page, after all the
// existing tabs open on the page have been closed, since previously cached
// resources are updated in the background.

// To learn more about the benefits of this model and instructions on how to
// opt-in, read https://cra.link/PWA

const isLocalhost = Boolean(
    window.location.hostname === 'localhost' ||
      // [::1] is the IPv6 localhost address.
      window.location.hostname === '[::1]' ||
      // 127.0.0.0/8 are considered localhost for IPv4.
      window.location.hostname.match(/^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/)
  );
  
  export function register(config) {
    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.href);
      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/facebook/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. Let's check if a service worker still exists or not.
          checkValidServiceWorker(swUrl, config);
  
          // 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://cra.link/PWA'
            );
          });
        } else {
          // Is not localhost. Just register service worker
          registerValidSW(swUrl, config);
        }
      });
    }
  }
  
  function registerValidSW(swUrl, config) {
    navigator.serviceWorker
      .register(swUrl)
      .then((registration) => {
        registration.onupdatefound = () => {
          const installingWorker = registration.installing;
          if (installingWorker == null) {
            return;
          }
          installingWorker.onstatechange = () => {
            if (installingWorker.state === 'installed') {
              if (navigator.serviceWorker.controller) {
                // At this point, the updated precached content has been fetched,
                // but the previous service worker will still serve the older
                // content until all client tabs are closed.
                console.log(
                  'New content is available and will be used when all ' +
                    'tabs for this page are closed. See https://cra.link/PWA.'
                );
  
                // Execute callback
                if (config && config.onUpdate) {
                  config.onUpdate(registration);
                }
              } 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.');
  
                // Execute callback
                if (config && config.onSuccess) {
                  config.onSuccess(registration);
                }
              }
            }
          };
        };
      })
      .catch((error) => {
        console.error('Error during service worker registration:', error);
      });
  }
  
  function checkValidServiceWorker(swUrl, config) {
    // Check if the service worker can be found. If it can't reload the page.
    fetch(swUrl, {
      headers: { 'Service-Worker': 'script' },
    })
      .then((response) => {
        // Ensure service worker exists, and that we really are getting a JS file.
        const contentType = response.headers.get('content-type');
        if (
          response.status === 404 ||
          (contentType != null && contentType.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, config);
        }
      })
      .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((error) => {
          console.error(error.message);
        });
    }
  }

 

 

Service worker가 적용된 모습을 개발자 도구 > Application > Service workers 에서 확인할 수 있다.

 

 

 

 

그리고 Lighthouse를 통해 PWA 점수를 확인해보면 짜잔!

 

 

빨간 세모 두개가 거슬린다.

각각 Learn more을 클릭해서 해결해주기.

 

 

Does not provide a valid

 

IOS 사파리는 manifest.json을 완벽하게 지원하지 않기 때문에 HTML 파일에 별도의 메타 태그를 추가해 둔다.

<link rel="apple-touch-icon" href="./icons/iconx192.png" />
<meta name="apple-mobile-web-app-capable" content="yes" />
<meta name="apple-mobile-web-app-status-bar-style" content="black" />
<meta name="apple-mobile-web-app-title" content="Colordentity" />

 

 

 

Manifest doesn't have a maskable icon

 

manifest.json의 icon 객체에

"purpose": "any maskable"

 

해당 코드를 추가한다.

 

 

 

 

 

 

짜잔 완료 !

 

 

 

 

 

 

 

이렇게 다운로드 표시가 뜬다!

 

다운로드를 클릭하니

 

 

크롬 앱에 다운로드가 받아지는 것을 확인할 수 있다.

 

 

클릭하면 이렇게 앱 처럼 보임 ㅎㅎ

 

 

 

 

 

 

참고 자료

https://yozm.wishket.com/magazine/detail/537/

https://marshallku.com/web/tips/%EC%9B%B9-%EC%82%AC%EC%9D%B4%ED%8A%B8%EB%A5%BC-pwa%EB%A1%9C-%EC%97%85%EB%8D%B0%EC%9D%B4%ED%8A%B8%ED%95%98%EA%B8%B0

https://dev.to/tebogonomnqa/how-to-turn-your-react-app-into-a-pwa-3km6

How to turn your react-app into a PWA

https://b.limminho.com/archives/1384