我在Web应用程序中使用Service Worker实现了推送WebAPI,正如许多文章在Web上解释的一样。 现在我需要在IndexedDB中存储一些数据,以便在关闭web应用程序时关闭它们(chrome选项卡关闭,服务员在后台执行)。 特别是我想存储一个简单的URL从检索通知数据(从服务器)。推WebAPI + IndexedDB + ServiceWorker
这里是我的代码:
self.addEventListener("push", (event) => {
console.log("[serviceWorker] Push message received", event);
notify({ event: "push" }); // This notifies the push service for handling the notification
var open = indexedDB.open("pushServiceWorkerDb", 1);
open.onsuccess =() => {
var db = open.result;
var tx = db.transaction("urls");
var store = tx.objectStore("urls");
var request = store.get("fetchNotificationDataUrl");
request.onsuccess = (ev) => {
var fetchNotificationDataUrl = request.result;
console.log("[serviceWorker] Fetching notification data from ->", fetchNotificationDataUrl);
if (!(!fetchNotificationDataUrl || fetchNotificationDataUrl.length === 0 || !fetchNotificationDataUrl.trim().length === 0)) {
event.waitUntil(
fetch(fetchNotificationDataUrl, {
credentials: "include"
}).then((response) => {
if (response.status !== 200) {
console.log("[serviceWorker] Looks like there was a problem. Status Code: " + response.status);
throw new Error();
}
return response.json().then((data) => {
if (!data) {
console.error("[serviceWorker] The API returned no data. Showing default notification", data);
//throw new Error();
showDefaultNotification({ url: "/" });
}
var title = data.Title;
var message = data.Message;
var icon = data.Icon;
var tag = data.Tag;
var url = data.Url;
return self.registration.showNotification(title, {
body: message,
icon: icon,
tag: tag,
data: {
url: url
},
requireInteraction: true
});
});
}).catch((err) => {
console.error("[serviceWorker] Unable to retrieve data", err);
var title = "An error occurred";
var message = "We were unable to get the information for this push message";
var icon = "/favicon.ico";
var tag = "notification-error";
return self.registration.showNotification(title, {
body: message,
icon: icon,
tag: tag,
data: {
url: "/"
},
requireInteraction: true
});
})
);
} else {
showDefaultNotification({ url: "/" });
}
}
};
});
不幸的是,当我收到新推的事件这是行不通的,显示出此异常:对未能执行“最好推迟”:
未捕获抛出:DOMException 'ExtendableEvent':事件处理程序已经完成。 在IDBRequest.request.onsuccess(https://192.168.0.102/pushServiceWorker.js:99:23)
我怎样才能解决这个问题?
在此先感谢
对于那些有兴趣的我用self.importScripts( '/库/ IDB-KEYVAL /距离/ IDB-KEYVAL-min.js');从服务工作者使用idb-keyval – Androidian