我想修改create-react-app
service worker文件并实现弹出消息,如果新的 service worker 准备好被激活,它将要求用户更新应用程序。我几乎完成了解决方案,但有一个陷阱。我想在用户确认 service worker 更新弹出窗口时重新加载应用程序,所以我在register
函数的末尾添加了一些代码,见下文:
export default function register(config) {
if (process.env.NODE_ENV === "production" && "serviceWorker" in navigator) {
// The URL constructor is available in all browsers that support SW.
const publicUrl = new URL(process.env.PUBLIC_URL, window.location)
if (publicUrl.origin !== window.location.origin) {
// Our service worker won't work if PUBLIC_URL is on a different origin
// from what our page is served on. This might happen if a CDN is used to
// serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
return
}
window.addEventListener("load", () => {
const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`
if (isLocalhost) {
// This is running on localhost. Lets check if a service worker still exists or not.
checkValidServiceWorker(swUrl, config)
// Add some additional logging to localhost, pointing developers to the
// service worker/PWA documentation.
navigator.serviceWorker.ready.then(() => {
console.log(
"This web app is being served cache-first by a service " +
"worker."
)
})
} else {
// Is not local host. Just register service worker
registerValidSW(swUrl, config)
}
let preventDevToolsReloadLoop
navigator.serviceWorker.addEventListener("controllerchange", function() {
// ensure refresh is called only once
if (preventDevToolsReloadLoop) {
return
}
preventDevToolsReloadLoop = true
console.log("reload")
window.location.reload(true)
})
})
}
}
但问题是它在第一次访问时也会重新加载应用程序,此时还不存在任何服务工作者。我该如何解决?