reactjs - React & Service Worker - 缓存内容 - 通知用户

Question

我有一个关于 service-workers 和 reactjs 的问题。

建议是通知用户有关缓存的内容或何时有新内容可用，以便用户了解缓存的内容。

我现在的问题是，我如何通知用户？

当我使用create-react-app时，在registerServiceWorker.js中有这样的代码，其中写着:

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 your web app.

function registerValidSW(swUrl) {
  navigator.serviceWorker
    .register(swUrl)
    .then(registration => {
      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        installingWorker.onstatechange = () => {
          if (installingWorker.state === '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 your web app.
              console.log('New content is available; please refresh.');
            } 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.');
            }
          }
        };
      };
    })
    .catch(error => {
      console.error('Error during service worker registration:', error);
    });
}

但实际上在这个脚本上，我当然无权访问文档，因为服务工作线程远离脚本工作。我如何在 react 组件中处理这个问题？

其他人如何处理此问题并通知用户？

Answer 1

您的问题中包含的代码在window客户端的上下文中运行。您可以完全控制显示您想要的任何 UI 元素。请随意修改这些 console.log() 语句并显示一些内容。

(有单独的代码在服务工作人员的上下文中运行，并且您是正确的，该代码无法访问 DOM。但这不是您要询问的代码。)