Service Worker skipWaiting无法激活当前正在等待的SW

Question

描述：

我们正在使用sw预缓存来预先缓存脚本，因此更新我们提供重载选项的脚本，因为我们正在监听工作者消息以跳过等待新安装的服务工作者，原因不明我们没有得到正确的

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();
});

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

您可以在install处理程序中无条件地调用它，也可以按照您似乎正在执行的模型，即监听message事件并有条件地调用skipWaiting() 。

如果你去条件路线，那么你应该修改你的客户页面的代码，以正确检测你正在注册的服务工作者何时进入waiting状态，并让用户选择以导致相应的方式与页面交互postMessage()告诉服务工作者skipWaiting() 。 基于你所说的，你已经尝试过了，但看起来你正在将消息发送给错误的服务工作者实例。

这是你的页面代码应该是这样的：

// 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();
  }
});

Answer 2

所以这就是我的想法...你的新服务工作者仍然在等待...因此，事件监听器仍然在你的老服务工作者上...你发送的任何消息仍然会被旧的sw捕获（因为新服务器正在等待） 。

如果你唯一的情况是让新的sw行动起来，你可以简单地刷新页面而不是发送消息