virtualx-engine/misc/dist/html/service-worker.js
Fabio Alessandrelli 73f396572a [HTML5] PWA service worker prefers cached version.
Use an offline first approach, where we prefer the cached version over
the network one.
This forces games using PWA to always re-export the project and not just
the PCK, so that the service worker version gets updated correctly, and
the end-user cache is correctly cleared on update.
2022-02-06 18:33:13 +01:00

105 lines
3.8 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 connection 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_PREFIX = "@GODOT_NAME@-sw-cache-";
const CACHE_NAME = CACHE_PREFIX + CACHE_VERSION;
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(caches.open(CACHE_NAME).then(cache => cache.addAll(CACHED_FILES)));
});
self.addEventListener("activate", (event) => {
event.waitUntil(caches.keys().then(
function (keys) {
// Remove old caches.
return Promise.all(keys.filter(key => key.startsWith(CACHE_PREFIX) && key != CACHE_NAME).map(key => caches.delete(key)));
}).then(function() {
// Enable navigation preload if available.
return ("navigationPreload" in self.registration) ? self.registration.navigationPreload.enable() : Promise.resolve();
})
);
});
async function fetchAndCache(event, cache, isCachable) {
// Use the preloaded response, if it's there
let response = await event.preloadResponse;
if (!response) {
// Or, go over network.
response = await self.fetch(event.request);
}
if (isCachable) {
// And update the cache
cache.put(event.request, response.clone());
}
return response;
}
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 to use cache first
const cache = await caches.open(CACHE_NAME);
if (event.request.mode === "navigate") {
// Check if we have full cache during HTML page request.
const fullCache = await Promise.all(FULL_CACHE.map(name => cache.match(name)));
const missing = fullCache.some(v => v === undefined);
if (missing) {
try {
// Try network if some cached file is missing (so we can display offline page in case).
return await fetchAndCache(event, cache, isCachable);
} catch (e) {
// And return the hopefully always cached offline page in case of network failure.
console.error("Network error: ", e);
return await caches.match(OFFLINE_URL);
}
}
}
const cached = await cache.match(event.request);
if (cached) {
return cached;
} else {
// Try network if don't have it in cache.
return await fetchAndCache(event, cache, isCachable);
}
}());
}
});
self.addEventListener("message", (event) => {
// No cross origin
if (event.origin != self.origin) {
return;
}
const id = event.source.id || "";
const msg = event.data || "";
// Ensure it's one of our clients.
self.clients.get(id).then(function (client) {
if (!client) {
return; // Not a valid client.
}
if (msg === "claim") {
self.skipWaiting().then(() => self.clients.claim());
} else if (msg === "clear") {
caches.delete(CACHE_NAME);
} else if (msg === "update") {
self.skipWaiting().then(() => self.clients.claim()).then(() => self.clients.matchAll()).then(all => all.forEach(c => c.navigate(c.url)));
} else {
onClientMessage(event);
}
});
});