I'm working on push notifications using service workers. I'm using the XHR(Ajax) approach to get my notification, here is a code snippet of service-worker.js:
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);
})
);
This code works fine the first time I run the curl, but the second time I got an error in the console:
Failed to execute 'fetch' on 'ServiceWorkerGlobalScope': Cannot construct a Request with a Request object that has already been used
What does this mean?
The problem is that
API_ENDPOINT
has already consumed by thefetch()
. You need a fresh request object each time you pass it to fetch so clone it before using it:Don't reuse the Request object multiple times, but do: