我正在使用服务工作者缓存Web应用程序的JS和CSS文件。我主要使用了来自Google Chrome示例的代码,我添加的唯一内容是通知和倒计时,在“有新的或更新的内容可用”时刷新窗口。
Google示例:https://github.com/GoogleChrome/sw-precache/blob/5699e5d049235ef0f668e8e2aa3bf2646ba3872f/demo/app/js/service-worker-registration.js 然而,这种情况发生得太频繁,我不明白为什么。服务器上的文件绝对没有任何更改,但有时我仍然会看到通知并且窗口重新加载。
我原本期望只有当由服务工作者控制的任何文件实际更改时才会发生这种情况(它们都通过Webpack进行哈希处理,肯定在中间没有更改)。
以下是我在
Google示例:https://github.com/GoogleChrome/sw-precache/blob/5699e5d049235ef0f668e8e2aa3bf2646ba3872f/demo/app/js/service-worker-registration.js 然而,这种情况发生得太频繁,我不明白为什么。服务器上的文件绝对没有任何更改,但有时我仍然会看到通知并且窗口重新加载。
我原本期望只有当由服务工作者控制的任何文件实际更改时才会发生这种情况(它们都通过Webpack进行哈希处理,肯定在中间没有更改)。
以下是我在
index.html
中使用的代码:/* eslint-env browser */
'use strict';
function reloadApp(delay) {
var t = delay || 0;
var message = 'New or updated content is available. Reloading app in {s} seconds';
var getMessage = function() { return message.replace('{s}', t) }
var div = document.createElement('div');
div.id = 'update-notification';
div.innerHTML = getMessage();
document.body.appendChild(div);
var intervalID = setInterval(function() {
t = t - 1;
if (t <= 0) {
clearInterval(intervalID);
window.location.reload();
}
else {
div.innerHTML = getMessage();
}
}, 1000);
}
if ('serviceWorker' in navigator && window.location.protocol === 'https:') {
navigator.serviceWorker.register('/service-worker.js').then(function(reg) {
console.info('serviceWorker registered');
reg.onupdatefound = function() {
var installingWorker = reg.installing;
installingWorker.onstatechange = function() {
switch (installingWorker.state) {
case 'installed':
if (navigator.serviceWorker.controller) {
reloadApp(5);
} else {
console.log('Content is now available offline!');
}
break;
case 'redundant':
console.error('The installing service worker became redundant.');
break;
}
};
};
}).catch(function(e) {
console.error('Error during service worker registration:', e);
});
}
这是我所做的更改:
switch (installingWorker.state) {
case '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 the page's interface.
console.log('New or updated content is available.');
} else {
变成:
switch (installingWorker.state) {
case 'installed':
if (navigator.serviceWorker.controller) {
reloadApp(5);
服务工作者本身是通过 sw-precache-webpack-plugin
生成的,哈希文件看起来像这样:
var precacheConfig = [["cms.CrudFactory.144344a2.js","6a65526f764f3caa4b8c6e0b84c1b31b"],["cms.routes.c20796b4.js","f8018476ceffa8b8f6ec00b297a6492d"],["common.cms-main.0f2db9ff.js","92017e838aff992e9f47f721cb07b6f0"],["common.licensing-main.8000b17d.js","0d43abd063567d5edaccdcf9c0e4c362"],["common.mediaplayer-main.314be5d2.js","2061501465a56e82d968d7998b9ac364"],["common.ordering-main.783e8605.js","0531c4a90a0fa9ea63fbe1f82e86f8c6"],["common.shared-main.0224b0ea.js","956ae4d2ddbddb09fb51804c09c83b22"],["common.stores-main.98246b60.js","cbdc46bc3abeac89f37e8f64b1737a22"],["component.App.284fec19.js","07f1923f1a0098bf9eba28fc7b307c18"],["component.AppToolbar.00e371de.js","9b542d4a85bdeece9d36ee4e389f6206"],["component.DevToolbar.652bf856.js","1744126e32774a93796146ac878ddd8e"],["component.Grid.4b964e52.js","755819ca2c7f911805e372401d638351"],["component.MediaPlayer.54db6e85.js","d0d8ae269665e810d1b997b473005f76"],["component.Search.05476f89.js","0cae8928aff533a6726dfaeb0661456a"],["data.country-list.d54f29a7.js","e27746418e02f75593a93b958a60807e"],["dev.sendSlackMessage.da8e22f4.js","ccb10829f18a727b79a5e8631bc4b2a2"],["index.html","02ff43eabc33c600e98785cffe7597d9"],["lib.gemini-scrollbar.df2fbf63.js","3941036bacb4a1432d22151ea7da073b"],["lib.isotope-horizontal.1604d974.js","6ac56d4296468c4428b5b5301a65938a"],["lib.isotope-packery.fabb73c3.js","808061641596e4b0ea2158b42d65915a"],["lib.react-color.265a6de0.js","f23f63d7e6934e381ffdc0405ecb449a"],["lib.react-date-picker.0a81fec3.js","778d1626645e439ad01e182ee589971a"],["lib.react-select.c768cf77.js","c8782991a161790ef2c9a2c7677da313"],["main.43e29bc6.js","fe6a6277acaa2a369ef235961be7bbcf"],["route.admin.CleanupPage.8b4bbf8e.js","8ab20412329e1ba4adc327713135be97"],["route.app.CmsPage.8a4303fb.js","0bf1506869db24bb9789c8a46449c8ad"],["route.app.CmsPageWrapper.accdebcc.js","c91e77aa8b518e1878761269deac22b6"],["route.app.ContactPage.75693d32.js","a530b00a5230a44897c2bf0aa9f402a8"],["route.app.PasswordResetExpiredDialog.65431bae.js","b5eef791dbd68edd4769bd6da022a857"],["route.app.SeriesDetailsPage.11a6989b.js","c52178b57767ae1bf94a9594cb32718e"],["route.cms.MetadataFormsPage.636188d2.js","e1e592b7e3dd82af774ac215524465c0"],["route.cms.PermissionsListPage.0e1e3075.js","9a3cc340a64238a1ab3ba1c0d483b7bd"],["route.cms.PermissionsPage.78a69f60.js","4b18e646715d6268e7aba3932f4e04a9"],["route.cms.SysconfigPage.f699b871.js","79bd1275213478f2ff1970e0b7341c49"],["styles.43e29bc620615f854714.css","b2e9e55e9ee2def2ae577ee1aaebda8f"],["styles.e0c12bb1c77e645e92d3.css","626778177949d72221e83b601c6c2c0f"],["translations.en.83fced0e.js","7e5509c23b5aafc1744a28a85c2950bb"],["translations.nl.4ae0b3bb.js","515ec7be7352a0c61e4aba99f0014a39"],["vendor.e0c12bb1.js","36ce9e0a59c7b4577b2ac4a637cb4238"]];
var cacheName = 'sw-precache-v3-nisv-client-' + (self.registration ? self.registration.scope : '');
问题:
- 为什么“新内容或更新内容”情况经常会发生?
- 假设
case 'installed': if (navigator.serviceWorker.controller) {
代表“有新内容或更新内容可用”,那这个假设是正确的吗? - 我该如何调试这个问题?