我在Web應用程序中使用Service Worker實現了推送WebAPI,正如許多文章在Web上解釋的一樣。 現在我需要在IndexedDB中存儲一些數據,以便在關閉web應用程序時關閉它們(chrome選項卡關閉,服務員在後臺執行)。 特別是我想存儲一個簡單的URL從檢索通知數據(從服務器)。推WebAPI + IndexedDB + ServiceWorker
這裏是我的代碼:
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,當我收到新推的事件這是行不通的,顯示出此異常:對未能執行「最好推遲」:
未捕獲拋出:DOMException 'ExtendableEvent':事件處理程序已經完成。 在IDBRequest.request.onsuccess(https://192.168.0.102/pushServiceWorker.js:99:23)
我怎樣才能解決這個問題?
在此先感謝
對於那些有興趣的我用self.importScripts( '/庫/ IDB-KEYVAL /距離/ IDB-KEYVAL-min.js');從服務工作者使用idb-keyval – Androidian