“ [url]”的FetchEvent导致网络错误响应：承诺被拒绝

Question

在尝试使用本教程从我的网站创建PWA-渐进式Web应用程序后，控制台中出现了这些错误和警告。

“ https://www.googletagmanager.com/gtag/js?id=UA-4562443-3 ”的FetchEvent导致网络错误响应：诺言被拒绝。 Promise.then（异步）（匿名）@ service-worker.js：228 service-worker.js：1未捕获（承诺）获取失败1:21 GET https://www.googletagmanager.com/gtag/js?id = UA-4562443-3 net :: ERR_FAILED“ https://fonts.googleapis.com/css?family=Open+Sans:300,400&display=swap&subset=cyrillic ”的FetchEvent导致网络错误响应：承诺被拒绝。 Promise.then（异步）（匿名）@ service-worker.js：228 service-worker.js：1未捕获（承诺）获取失败1:28 GET https://fonts.googleapis.com/css?family=Open + Sans：300,400＆display = swap＆subset = cyrillic net :: ERR_FAILED“ https://widget.uservoice.com/VuHfPZ0etI2eQ4REt1tiUg.js ”的FetchEvent导致网络错误响应：承诺被拒绝。 Promise.then（异步）（匿名）@ service-worker.js：228 service-worker.js：1未捕获（承诺）获取失败1：894 GET https://widget.uservoice.com/VuHfPZ0etI2eQ4REt1tiUg.js网络： ：错误_失败

实际上效果很好。 我可以在Chrome Dev Tools的“审核”中获得完全正常运行的PWA图标。 很棒，但是刷新之后，我得到了所有这些错误。 我位于网站根目录的service-worker.js看起来像这样

 "use strict"; const SERVICE_WORKER_VERSION = "REPLACED_WITH_SERVICE_WORKER_VERSION"; // updated with tools/service_worker_version.js (String) const CACHE_VERSION = SERVICE_WORKER_VERSION; //const fileNamesToSaveInCache = ["/"]; const HOME = "/"; const OFFLINE_ALTERNATIVE = "/offline"; const fileNamesToSaveInCache = []; const fileNamesToSaveInCacheProd = [ OFFLINE_ALTERNATIVE, "/", "/publics/img/favicon/fav.gif", "/publics/css/style.css", "/publics/css/searchhelp.css", "/publics/css/Helpa.css", ]; const rtcLength = 4; // "rtc/".length; const rtcFetchDelay = 10000;//ms const origin = location.origin; const answerFromfileName = {}; const resolveFromfileName = {}; const rejectFromfileName = {}; const timeOutIdFromfileName = {}; let logLater = []; // todo put all into single container const resolveFetchFromPeerToPeer = function (fileName) { clearTimeout(timeOutIdFromfileName[fileName]); resolveFromfileName[fileName](answerFromfileName[fileName]); delete answerFromfileName[fileName];//stop listening delete resolveFromfileName[fileName]; delete rejectFromfileName[fileName]; }; const rejectFetchFromPeerToPeer = function (fileName, reason) { if (rejectFromfileName[fileName]) { rejectFromfileName[fileName](reason); delete resolveFromfileName[fileName]; delete rejectFromfileName[fileName]; } }; const fetchFromPeerToPeer = function (customRequestObject) { /*asks all page for a fileName*/ const fileName = customRequestObject.header.fileName; const promise = new Promise(function (resolve, reject) { resolveFromfileName[fileName] = resolve; rejectFromfileName[fileName] = reject; if (answerFromfileName.hasOwnProperty(fileName)) { resolveFetchFromPeerToPeer(fileName); } timeOutIdFromfileName[fileName] = setTimeout(function() { rejectFetchFromPeerToPeer(fileName, "No answer after 10 seconds"); }, rtcFetchDelay); }); self.clients.matchAll().then(function(clientList) { clientList.forEach(function(client) { client.postMessage(customRequestObject); }); }); return promise; }; const logInTheUI = (function () { //console.log("logInTheUI function exists"); return function (what) { console.log(what); self.clients.matchAll().then(function(clientList) { clientList.forEach(function(client) { client.postMessage({LOG: JSON.parse(JSON.stringify(what))}); }); }); }; }()); const logInTheUIWhenActivated = function (what) { logLater.push(what); }; const fetchFromMainServer = function (request, options = {}) { /*wrap over fetch. The problem with fetch here, it doesn't reject properly sometimes see if statement below*/ return fetch(request, options).then(function (fetchResponse) { // console.log("fetchFromMainServer:", fetchResponse.ok, fetchResponse); // logInTheUI([request, options]); if ((!fetchResponse) || (!fetchResponse.ok)) { return Promise.reject("fetch failed"); } return fetchResponse; }); }; const fetchFromCache = function (request) { return caches.open(CACHE_VERSION).then(function (cache) { return cache.match(request).then(function (CacheResponse) { //console.log("fetchFromCache:", CacheResponse.ok, CacheResponse); if ((!CacheResponse) || (!CacheResponse.ok)) { return Promise.reject("Not in Cache"); } return CacheResponse; }); }); }; const isLocalURL = function (url) { return !(String(url).match("rtc")); }; const fillServiceWorkerCache2 = function () { /*It will not cache and also not reject for individual resources that failed to be added in the cache. unlike fillServiceWorkerCache which stops caching as soon as one problem occurs. see http://stackoverflow.com/questions/41388616/what-can-cause-a-promise-rejected-with-invalidstateerror-here*/ return caches.open(CACHE_VERSION).then(function (cache) { return Promise.all( fileNamesToSaveInCache.map(function (url) { return cache.add(url).catch(function (reason) { return logInTheUIWhenActivated([url + "failed: " + String(reason)]); }); }) ); }); }; const latePutToCache = function (request, response) { return caches.open(CACHE_VERSION).then(function(cache) { cache.put(request, response.clone()); return response; }); }; const deleteServiceWorkerOldCache = function () { return caches.keys().then(function (cacheVersions) { return Promise.all( cacheVersions.map(function (cacheVersion) { if (CACHE_VERSION === cacheVersion) { //console.log("No change in cache"); } else { //console.log("New SERVICE_WORKER_VERSION of cache, delete old"); return caches.delete(cacheVersion); } }) ); }); }; const useOfflineAlternative = function () { return fetchFromCache(new Request(OFFLINE_ALTERNATIVE)); }; const isAppPage = function (url) { /*appPage does not work offline, and we don't serve it if offline returns Boolean*/ return (origin + HOME) === url; }; self.addEventListener("install", function (event) { /*the install event can occur while another service worker is still active waitUntil blocks the state (here installing) of the service worker until the promise is fulfilled (resolved or rejected). It is useful to make the service worker more readable and more deterministic save in cache some static fileNames this happens before activation */ event.waitUntil( fillServiceWorkerCache2() .then(skipWaiting) ); }); self.addEventListener("activate", function (event) { /* about to take over, other service worker are killed after activate, syncronous a good moment to clear old cache*/ event.waitUntil(deleteServiceWorkerOldCache().then(function() { //console.log("[ServiceWorker] Skip waiting on install caches:", caches); return self.clients.claim(); })); }); self.addEventListener("message", function (event) { const message = event.data; /* if (message.hasOwnProperty("FUTURE")) { console.log(message.FUTURE); return; } */ const fileName = message.fileName; const answer = message.answer; answerFromfileName[fileName] = answer; //console.log(fileName, answer, resolveFromfileName); if (resolveFromfileName.hasOwnProperty(fileName)) {// resolveFetchFromPeerToPeer(fileName); } }); self.addEventListener("fetch", function (fetchEvent) { /* fetchEvent interface FetchEvent see https://www.w3.org/TR/service-workers/#fetch-event-interface IMPORTANT: fetchEvent.respondWith must be called inside this handler immediately synchronously fetchEvent.respondWith must be called with a response object or a promise that resolves with a response object. if fetchEvent.respondWith is called later in a callback the browser will take over and asks the remote server directly, do not do that why have fetchEvent.respondWith( and not respond with the return value of the callback function ? --> It allows to do other thing before killing the service worker, like saving stuff in cache */ const request = fetchEvent.request;//Request implements Body; //const requestClone = request.clone(); //no need to clone ? const url = request.url; if (logLater) { logLater.forEach(logInTheUI); logLater = undefined; } // logInTheUI(["fetch service worker " + SERVICE_WORKER_VERSION, fetchEvent]); // Needs to activate to handle fetch if (isLocalURL(url)) { //Normal Fetch if (request.method === "POST") { // logInTheUI(["POST ignored", request]); return; } // logInTheUI(["Normal Fetch"]); fetchEvent.respondWith( fetchFromCache(request.clone()).then(function (cacheResponse) { /* cannot use request again from here, use requestClone */ //console.log(request, url); return cacheResponse; }).catch(function (reason) { // We don't have it in the cache, fetch it // logInTheUI(fetchEvent); return fetchFromMainServer(request); }).then(function (mainServerResponse) { if (isAppPage(url)) { return mainServerResponse; } return latePutToCache(request, mainServerResponse).catch( function (reason) { /*failed to put in cache do not propagate catch, not important enough*/ return mainServerResponse; } ); }).catch(function (reason) { if (isAppPage(url)) { //if it is the landing page that is asked return useOfflineAlternative(); //todo if we are offline , display /offline directly } return Promise.reject(reason); }) ); } else { // Peer to peer Fetch //console.log(SERVICE_WORKER_VERSION, "rtc fetch" url:", fetchEvent.request.url); // request, url are defined const method = request.method; const requestHeaders = request.headers; //logInTheUI(["Special Fetch"]); const customRequestObject = { header: { fileName: url.substring(url.indexOf("rtc/") + rtcLength), method }, body: "" }; requestHeaders.forEach(function (value, key) { //value, key correct order //is there a standard way to use Object.assign with Map like iterables ? //todo handle duplicates //https://fetch.spec.whatwg.org/#terminology-headers customRequestObject.header[key] = value; }); //console.log(request); fetchEvent.respondWith( /*should provide the peer the full request*/ request.arrayBuffer().then(function (bodyAsArrayBuffer) { const bodyUsed = request.bodyUsed; if (bodyUsed && bodyAsArrayBuffer) { customRequestObject.body = bodyAsArrayBuffer; } }).catch(function (reason) { /*console.log("no body sent, a normal GET or HEAD request has no body", reason);*/ }).then(function (notUsed) { return fetchFromPeerToPeer(customRequestObject); }).then(function (response) { const responseInstance = new Response(response.body, { headers: response.header, status: response.header.status || 200, statusText : response.header.statusText || "OK" }); return responseInstance; }).catch(function (error) { const responseInstance = new Response(`<html><p>${error}</p></html>`, { headers: { "Content-type": "text/html" }, status: 500, statusText : "timedout" }); return responseInstance; }) ); } /*here we could do more with event.waitUntil()*/ }); 

我猜问题出在加载这些外部库。 因此，这是我的代码加载这些库。

 // Include the UserVoice JavaScript SDK (only needed once on a page) UserVoice = window.UserVoice || []; (function() { var uv = document.createElement('script'); uv.type = 'text/javascript'; uv.async = true; uv.src = '//widget.uservoice.com/VuHfPZ0etI2eQ4REt1tiUg.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(uv, s) })(); // // UserVoice Javascript SDK developer documentation: // https://www.uservoice.com/o/javascript-sdk // // Set colors UserVoice.push(['set', { accent_color: '#448dd6', trigger_color: 'white', trigger_background_color: 'rgba(46, 49, 51, 0.6)' }]); // Identify the user and pass traits // To enable, replace sample data with actual user traits and uncomment the line UserVoice.push(['identify', { //email: 'john.doe@example.com', // User's email address //name: 'John Doe', // User's real name //created_at: 1364406966, // Unix timestamp for the date the user signed up //id: 123, // Optional: Unique id of the user (if set, this should not change) //type: 'Owner', // Optional: segment your users by type //account: { // id: 123, // Optional: associate multiple users with a single account // name: 'Acme, Co.', // Account name // created_at: 1364406966, // Unix timestamp for the date the account was created // monthly_rate: 9.99, // Decimal; monthly rate of the account // ltv: 1495.00, // Decimal; lifetime value of the account // plan: 'Enhanced' // Plan name for the account //} }]); // Add default trigger to the bottom-right corner of the window: UserVoice.push(['addTrigger', {mode: 'contact', trigger_position: 'bottom-right'}]); // Or, use your own custom trigger: //UserVoice.push(['addTrigger', '#id', { mode: 'contact' }]); // Autoprompt for Satisfaction and SmartVote (only displayed under certain conditions) UserVoice.push(['autoprompt', {}]); });//ready 

 @import url('https://fonts.googleapis.com/css?family=Open+Sans:300,400&display=swap&subset=cyrillic'); @font-face { font-family: 'fa-solid-900'; font-display: swap; src: url(https://use.fontawesome.com/releases/v5.8.2/webfonts/fa-solid-900.woff2) format('woff2'); } @font-face { font-family: 'fa-brands-400'; font-display: swap; src: url(https://use.fontawesome.com/releases/v5.8.2/webfonts/fa-brands-400.woff2) format('woff2'); } 

 <script async src="https://www.googletagmanager.com/gtag/js?id=UA-number-3"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-number-3'); </script> 

我应该怎么做才能解决那些错误。 这是我第一次尝试PWA，所以我迷路了。

Answer 1

我最终使用了Workbox ，现在一切正常。