2
我正在使用服務人員推送通知。我使用XHR(阿賈克斯)的方法來得到我的通知,這裏是服務worker.js的代碼片段:爲什麼此代碼無法執行'fetch'?
var API_ENDPOINT = new Request('/getNotification', {
redirect: 'follow'});
event.waitUntil(
fetch(API_ENDPOINT, {credentials: 'include' })
.then(function(response) {
console.log(response);
if (response.status && response.status != 200) {
// Throw an error so the promise is rejected and catch() is executed
throw new Error('Invalid status code from API: ' +
response.status);
}
// Examine the text in the response
return response.json();
})
.then(function(data) {
console.log('API data: ', data);
var title = 'TEST';
var message = data['notifications'][0].text;
var icon = data['notifications'][0].img;
// Add this to the data of the notification
var urlToOpen = data['notifications'][0].link;
var notificationFilter = {
tag: 'Test'
};
var notificationData = {
url: urlToOpen,
parsId:data['notifications'][0].parse_id
};
if (!self.registration.getNotifications) {
return showNotification(title, message, icon, notificationData);
}
})
.catch(function(err) {
console.error('A Problem occured with handling the push msg', err);
var title = 'An error occured';
var message = 'We were unable to get the information for this ' +
'push message';
return showNotification(title, message);
})
);
此代碼工作正常,我第一次運行卷曲,但第二次我在控制檯出現錯誤:
Failed to execute 'fetch' on 'ServiceWorkerGlobalScope': Cannot construct a Request with a Request object that has already been used
這是什麼意思?
謝謝你,你解決了我的問題! 對於那些誰得到一個錯誤,如: 網絡錯誤(如超時,連接中斷或無法連接的主機)發生 無法執行「取」上「ServiceWorkerGlobalScope」:不能建立與具有請求對象的請求已被使用 這是因爲您可能使用服務工作者,然後攔截抓取事件,並在內部嘗試在相同的請求後立即重新執行抓取,因爲緩存命中失敗。在這種情況下,不要執行提取(request),而是執行fetch(request.clone()),它會創建一個新的請求。 –