every.channel/apps/tauri/ui/sw.js
2026-02-15 16:17:27 -05:00

103 lines
2.6 KiB
JavaScript

/* every.channel PWA service worker
*
* Goal: cache the app shell so it can be installed and load offline.
* Do not interfere with media fetching/streaming: always network-pass-through
* for non-GET requests and for large binary media responses.
*/
const CACHE_NAME = "every.channel-shell-v1";
const SHELL = [
"./",
"./index.html",
"./style.css",
"./manifest.webmanifest",
"./icons/icon-192.png",
"./icons/icon-512.png",
"./icons/apple-touch-icon.png",
];
self.addEventListener("install", (event) => {
event.waitUntil(
caches
.open(CACHE_NAME)
.then((cache) => cache.addAll(SHELL))
.then(() => self.skipWaiting())
);
});
self.addEventListener("activate", (event) => {
event.waitUntil(
caches
.keys()
.then((keys) =>
Promise.all(
keys.map((key) => {
if (key !== CACHE_NAME) return caches.delete(key);
return Promise.resolve();
})
)
)
.then(() => self.clients.claim())
);
});
function isNavigationRequest(request) {
return request.mode === "navigate";
}
function isMediaRequest(request) {
const url = new URL(request.url);
const path = url.pathname.toLowerCase();
return (
path.endsWith(".m3u8") ||
path.endsWith(".m4s") ||
path.endsWith(".mp4") ||
path.endsWith(".ts")
);
}
self.addEventListener("fetch", (event) => {
const { request } = event;
if (request.method !== "GET") return;
// Don't cache/modify streaming media requests.
if (isMediaRequest(request)) {
event.respondWith(fetch(request));
return;
}
// For navigations, prefer network but fall back to cached shell.
if (isNavigationRequest(request)) {
event.respondWith(
fetch(request).catch(() => caches.match("./index.html").then((r) => r || Response.error()))
);
return;
}
// Cache-first for same-origin static assets; network fallback.
const url = new URL(request.url);
if (url.origin === self.location.origin) {
event.respondWith(
caches.match(request).then((cached) => {
if (cached) return cached;
return fetch(request)
.then((resp) => {
// Avoid caching huge binary responses.
const len = resp.headers.get("content-length");
const tooBig = len && Number(len) > 5_000_000;
if (resp.ok && !tooBig) {
const clone = resp.clone();
caches.open(CACHE_NAME).then((cache) => cache.put(request, clone)).catch(() => {});
}
return resp;
})
.catch(() => cached || Response.error());
})
);
return;
}
// Default: network.
event.respondWith(fetch(request));
});