我正在用create-rect应用程序编写我的第一个react应用程序，但在设置pwa时遇到了问题。
我试图在新的服务人员注册上显示一个小吃条，但即使使用模板代码，我也无法使其工作。
下面是我的service-worker.js/src/(与cra模板中的相同(
/* 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.下面是我的serviceWorkerRegistration.js/src/utils。也几乎与最初交付的一个位置更改和一个console.log消息修改相同(我确信我正确地导入了它，因为onSuccess回调是有效的(
// 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! Click the pop-up notification to update it!'
);
// 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);
});
}
}我正在用useEffect钩子注册sw:
useEffect(() => {
registerSW({
onSuccess: () => setShowSuccess(true),
onUpdate: sw => {
console.log('onUpdate triggered')
setShowReload(true)
setSW(sw)
},
});
}, []);onSuccess回调运行良好，但问题是，onUpdate回调根本不会被触发。serviceWorkerRegistration本身中的console.log消息("新内容可用！单击弹出通知进行更新！"(也不会出现。
我的猜测是，一些浏览器api已经更改，onupdatefound api将不再工作。但我不确定这是否是因为我的应用程序在每次页面加载时都会调用sw进行注册，而当时注册的服务工作者已经是新的sw.js，因此不会有更新。
我检查了我以前的项目，发现我正在监听navigator.serviceWorker的controllerange。我不确定哪种方法是正确的，以及如何在react中实现此功能。我很好奇onUpdate回调是什么时候调用的，以及我是否正确使用了它。
提前感谢！
经过一些基于console.log的调试，我发现这个错误是由window.onload之后加载的sw注册模块引起的，导致模板代码不再有用，因为registerValidSW函数只有在达到window.onlad目标时才会触发。
我已经修改了window.onload部分来解决这个问题：
const callRegisterValidSW = () => {
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.'
);
});
} else {
// Is not localhost. Just register service worker
registerValidSW(swUrl, config);
}
};
if (document.readyState === "complete") {
callRegisterValidSW();
} else {
window.addEventListener('load', callRegisterValidSW);
}如果有人看到https://github.com/cra-template/pwa/，我们可以在附带的swRegistration函数中添加一些关于这一部分的注释。