服务人员skipWaiting无法激活当前正在等待的软件

Question

描述：

我们正在使用sw precache预先缓存脚本，因此要更新脚本，我们提供了reload选项，因为我们正在监听工作程序消息，以跳过由于未知原因而等待新安装的服务工作程序的问题，我们无法正确执行

importScript

// GETTING OLD SW reference (self) and NOT getting newly installed SW reference

self.addEventListener('message', function(event) {
    *// not working*
    self.skipWaiting();
});



// But if we put skipWaiting() in 'install' listener 
// it is getting correct new SW reference and working correctly

self.addEventListener('install', function(event) {
    // self.skipWaiting();
});

软件注册

if('serviceWorker' in window.navigator) {
      window.addEventListener('load', function() {
        window.navigator.serviceWorker.register("/serviceWorker.js").then(function(registration) {
          console.log("ServiceWorker registration successful with scope: ", registration);
          registration.onupdatefound = function() {
            console.log('NEW WILD WORKER HAS SPAWNED.!', registration);
            var installedWorker = registration.installing;
            installedWorker.onstatechange = function() {
              if (installedWorker.state === 'installed') {
                if (navigator.serviceWorker.controller) {
                  console.log('Updated content is available RELOAD!', navigator.serviceWorker.controller);
                  var el = document.getElementById('feature');
                  el.style['display'] = 'block';
                }
              }
            }
          }
        }).catch(function(error) {
          console.error("ServiceWorker registration failed: ", error);
        });
      });
      window.navigator.serviceWorker.addEventListener('controllerchange', function() {
        console.log('SERVICE WORKER UPDATED');
      });
    }

webpack配置

new SWPrecacheWebpackPlugin({
        cacheId: 'pwa',
        filename: 'serviceWorker.js',
        staticFileGlobsIgnorePatterns: [/\.map$/, /\.json$/, /_nch\.[0-9a-z]+\.[js, css]+/g, /webpackManifest\.[0-9a-z]+\.js/g, /.DS_Store\.[0-9a-z]+/g],
        importScripts: ['offline/offline.1a2b3c4df1.js'],
        dontCacheBustUrlsMatching: /./,
        minify: false,
        skipWaiting: false,
        runtimeCaching: [ {
          urlPattern: /_nch\.[0-9a-z]+\.[js, css]+/g,
          handler: 'fastest',
          options: {
            cache: {
              name: 'jd-internal-script',
              maxEntries: 10,
            },
          },
        }, {
          urlPattern: /webpackManifest\.[0-9a-z]+\.js/g,
          handler: 'networkFirst',
          options: {
            cache: {
              name: 'jd-root-doc',
            },
          },
        }],
      }),

Answer 1

有关最佳文档，请skipWaiting()访问https://developers.google.com/web/fundamentals/instant-and-offline/service-worker/lifecycle#skip_the_waiting_phase

您可以在install处理程序中无条件调用它，也可以遵循您似乎正在做的模型，即侦听message事件并skipWaiting()有条件地调用。

如果使用条件路由，则应修改客户端页面的代码以正确检测正在注册的服务工作者何时进入waiting状态，并为用户提供与页面进行交互的选项，从而产生对应postMessage()于告诉服务人员skipWaiting()。根据您的发言，您已经尝试过此操作，但似乎您正在将消息发送到错误的Service Worker实例。

这是您页面的代码应如下所示：

// On your page:
if ('serviceWorker' in navigator) {
  window.addEventListener('load', function() {
    navigator.serviceWorker.register('service-worker.js').then(function(reg) {
      reg.onupdatefound = function() {
        var newSW = reg.installing;
        newSW.onstatechange = function() {
          if (newSW.state === 'waiting') {
            // This assumes there's a button with id='skip-waiting-button' that
            // users should click to get the new SW to activate immediately.
            var button = document.querySelector('#skip-waiting-button');
            button.addEventListener('click', function() {
              newSW.postMessage('skipWaiting');
            });
            // Assume that 'display' is 'none' initially.
            button.style.display = 'inline';
          }
          // Handle whatever other SW states you care about, like 'active'.
        };
      };
    })
  });
}

// In your service worker:
self.addEventListener('message', event => {
  if (event.data === 'skipWaiting') {
    self.skipWaiting();
  }
});