godot/misc/dist/html/service-worker.js
Fabio Alessandrelli 88c060b00d [HTML5] Export as Progressive Web App.
Adds possibility to export as a progressive web app.
Allows customizing base icons, display mode, orientation and offline
page.
2021-04-27 14:44:31 +02:00

74 lines
2.8 KiB
JavaScript

// This service worker is required to expose an exported Godot project as a
// Progressive Web App. It provides an offline fallback page telling the user
// that they need an Internet conneciton to run the project if desired.
// Incrementing CACHE_VERSION will kick off the install event and force
// previously cached resources to be updated from the network.
const CACHE_VERSION = "@GODOT_VERSION@";
const CACHE_NAME = "@GODOT_NAME@-cache";
const OFFLINE_URL = "@GODOT_OFFLINE_PAGE@";
// Files that will be cached on load.
const CACHED_FILES = @GODOT_CACHE@;
// Files that we might not want the user to preload, and will only be cached on first load.
const CACHABLE_FILES = @GODOT_OPT_CACHE@;
const FULL_CACHE = CACHED_FILES.concat(CACHABLE_FILES);
self.addEventListener("install", (event) => {
event.waitUntil(async function () {
const cache = await caches.open(CACHE_NAME);
// Clear old cache (including optionals).
await Promise.all(FULL_CACHE.map(path => cache.delete(path)));
// Insert new one.
const done = await cache.addAll(CACHED_FILES);
return done;
}());
});
self.addEventListener("activate", (event) => {
event.waitUntil(async function () {
if ("navigationPreload" in self.registration) {
await self.registration.navigationPreload.enable();
}
}());
// Tell the active service worker to take control of the page immediately.
self.clients.claim();
});
self.addEventListener("fetch", (event) => {
const isNavigate = event.request.mode === "navigate";
const url = event.request.url || "";
const referrer = event.request.referrer || "";
const base = referrer.slice(0, referrer.lastIndexOf("/") + 1);
const local = url.startsWith(base) ? url.replace(base, "") : "";
const isCachable = FULL_CACHE.some(v => v === local) || (base === referrer && base.endsWith(CACHED_FILES[0]));
if (isNavigate || isCachable) {
event.respondWith(async function () {
try {
// Use the preloaded response, if it's there
let request = event.request.clone();
let response = await event.preloadResponse;
if (!response) {
// Or, go over network.
response = await fetch(event.request);
}
if (isCachable) {
// Update the cache
const cache = await caches.open(CACHE_NAME);
cache.put(request, response.clone());
}
return response;
} catch (error) {
const cache = await caches.open(CACHE_NAME);
if (event.request.mode === "navigate") {
// Check if we have full cache.
const cached = await Promise.all(FULL_CACHE.map(name => cache.match(name)));
const missing = cached.some(v => v === undefined);
const cachedResponse = missing ? await caches.match(OFFLINE_URL) : await caches.match(CACHED_FILES[0]);
return cachedResponse;
}
const cachedResponse = await caches.match(event.request);
return cachedResponse;
}
}());
}
});