tilfluktsrom/pwa/node_modules/workbox-recipes/offlineFallback.js
Ole-Morten Duesund e8428de775 Add progressive web app companion for cross-platform access
Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-08 17:41:38 +01:00

59 lines
2.4 KiB
JavaScript

/*
Copyright 2020 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
import { setCatchHandler } from 'workbox-routing/setCatchHandler.js';
import { matchPrecache } from 'workbox-precaching/matchPrecache.js';
import './_version.js';
/**
* An implementation of the [comprehensive fallbacks recipe]{@link https://developers.google.com/web/tools/workbox/guides/advanced-recipes#comprehensive_fallbacks}. Be sure to include the fallbacks in your precache injection
*
* @memberof workbox-recipes
*
* @param {Object} [options]
* @param {string} [options.pageFallback] Precache name to match for pag fallbacks. Defaults to offline.html
* @param {string} [options.imageFallback] Precache name to match for image fallbacks.
* @param {string} [options.fontFallback] Precache name to match for font fallbacks.
*/
function offlineFallback(options = {}) {
const pageFallback = options.pageFallback || 'offline.html';
const imageFallback = options.imageFallback || false;
const fontFallback = options.fontFallback || false;
self.addEventListener('install', (event) => {
const files = [pageFallback];
if (imageFallback) {
files.push(imageFallback);
}
if (fontFallback) {
files.push(fontFallback);
}
event.waitUntil(self.caches
.open('workbox-offline-fallbacks')
.then((cache) => cache.addAll(files)));
});
const handler = async (options) => {
const dest = options.request.destination;
const cache = await self.caches.open('workbox-offline-fallbacks');
if (dest === 'document') {
const match = (await matchPrecache(pageFallback)) ||
(await cache.match(pageFallback));
return match || Response.error();
}
if (dest === 'image' && imageFallback !== false) {
const match = (await matchPrecache(imageFallback)) ||
(await cache.match(imageFallback));
return match || Response.error();
}
if (dest === 'font' && fontFallback !== false) {
const match = (await matchPrecache(fontFallback)) ||
(await cache.match(fontFallback));
return match || Response.error();
}
return Response.error();
};
setCatchHandler(handler);
}
export { offlineFallback };