我正在关注在 React 中创建自定义服务工作者的教程。我完成了它,但它没有按预期工作。当我离线访问该页面时,它只呈现谷歌默认的“无互联网”页面。
这是我的代码
public/customWorker.js
::
console.log("Hello World");
src/sw.js
:
workbox.skipWaiting();
workbox.clientsClaim();
self.addEventListener("install", (event) => {
console.log("install");
});
self.addEventListener("activate", (event) => {
console.log("activate");
});
workbox.precaching.precacheAndRoute(self.__precacheManifest || []);
src/serviceWorker.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.
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}$/
)
);
export function register(config) {
if (process.env.NODE_ENV === "production" && "serviceWorker" in navigator) {
// The URL constructor is available in all browsers that support SW.
const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href);
if (publicUrl.origin !== window.location.origin) {
// Our service worker won't work if PUBLIC_URL is on a different origin
// from what our page is served on. This might happen if a CDN is used to
// serve assets; see https://github.com/facebook/create-react-app/issues/2374
return;
}
window.addEventListener("load", () => {
const swUrl = `${process.env.PUBLIC_URL}/customWorker.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(
);
});
} 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."
);
// 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)
.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();
});
}
}
config.js
: (在项目的根目录中)
const WorkboxWebpackPlugin = require("workbox-webpack-plugin");
module.exports = function override(config, env) {
config.plugins = config.plugins.map((plugin) => {
if (plugin.constructor.name === "GenerateSW") {
return new WorkboxWebpackPlugin.InjectManifest({
swSrc: "./src/sw.js",
swDest: "service-worker.js",
});
}
return plugin;
});
return config;
};
package.json
:
"scripts": {
"start": "react-app-rewired start",
"build": "react-app-rewired build",
"test": "react-app-rewired test",
"eject": "react-app-rewired eject"
},
我跑过去npm run build
看到了服务站点localhost:5000
。对于第一次访问,它会打印:
任何帮助是极大的赞赏!
谢谢你!