serviceworker.js

var staticCacheName = "pwa";
self.addEventListener("install", function (event) {
    event.waitUntil(preLoad());
});
self.addEventListener("fetch", function (event) {
    event.respondWith(
        checkResponse(event.request).catch(function () {
            console.log("Fetch from cache successful!");
            return returnFromCache(event.request);
        })
    );
    console.log("Fetch successful!");
    event.waitUntil(addToCache(event.request));
});
self.addEventListener("sync", (event) => {
    if (event.tag === "syncMessage") {
        console.log("Sync successful!");
    }
});
self.addEventListener("push", function (event) {
    if (event && event.data) {
        var data = event.data.json();
        if (data.method == "pushMessage") {
            console.log("Push notification requested");
            if (Notification.permission === "granted") {
                event.waitUntil(
                    self.registration.showNotification("To Do List", {
                        body: data.message,
                    }).catch(function(error) {
                        console.error("Error showing notification:", error);
                    })
                );
            } else if (Notification.permission === "denied") {
                console.error("Notification permission denied.");
                // Handle the case where notification permission is denied, such as showing a message to
                //the user.
            } else {
                Notification.requestPermission().then(function(permission) {
                    if (permission === "granted") {
                        console.log("Notification permission granted, showing notification");
                        self.registration.showNotification("To Do List", {
                            body: data.message,
                        });
                    } else {
                        console.error("Notification permission denied.");
                        // Handle the case where notification permission is denied after requesting.
                    }
                });
            }
        }
    }
});

var filesToCache = ["/", "/index.html"];
var preLoad = function () {
    return caches.open("index").then(function (cache) {
        return cache.addAll(filesToCache);
    });
};
var checkResponse = function (request) {
    return new Promise(function (fulfill, reject) {
        fetch(request)
        .then(function (response) {
            if (response.status !== 404) {
                fulfill(response);
            } else {
                reject();
            }
        })
        .catch(reject);
    });
};
var addToCache = function (request) {
    return caches.open("index").then(function (cache) {
        return fetch(request).then(function (response) {
            return cache.put(request, response);
        });
    });
};
var returnFromCache = function (request) {
    return caches.open("index").then(function (cache) {
        return cache.match(request).then(function (matching) {
            if (!matching || matching.status == 404) {
                return cache.match("index.html");
            } else {
                return matching;
            }
        });
    });
};
self.addEventListener("activate", (event) => {
    event.waitUntil(
        caches.keys().then((cacheNames) => {
            return Promise.all(
                cacheNames
                .filter((name) => {
                    return name !== staticCacheName;
                })
                .map((name) => {
                    return caches.delete(name);
                })
            );
        })
    );
});