blob: 5d4485413e1be2b263d017204a3b4fdcbe593352 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
(function () {
function check(url, method, callback) {
const http = new XMLHttpRequest();
http.onreadystatechange = function () {
if (http.readyState === 4 && http.status === 200) {
if (callback) callback(http);
}
};
http.open(method, url);
http.setRequestHeader("Pragma", "no-cache");
http.setRequestHeader("Cache-Control", "no-cache");
http.send();
}
function update(id) {
const url = self.location.href;
check(url, "HEAD", function (request) {
const local = document.querySelector('meta[name="last-modified"]').content;
const remote = request.getResponseHeader("last-modified") || local;
const localHour = local.substring(0, local.length - 9);
const remoteHour = remote.substring(0, remote.length - 9);
const modified = localHour !== remoteHour;
if (modified) {
const indicator = document.querySelector("a[data-update]");
check(url, "GET");
indicator.href = url;
indicator.removeAttribute("id");
indicator.dataset.update = "refresh";
clearInterval(id);
}
console.log("R: " + remote);
console.log("L: " + local);
console.log("M: " + modified);
});
}
self.addEventListener("load", function () {
let meta = document.querySelector('meta[name="refresh"]');
if (meta) meta = document.querySelector('meta[name="refresh"]').content;
const interval = meta || 3600000;
const monitor = setInterval(function () {
if (navigator.onLine) update(monitor);
}, interval);
});
})();
|
