service worker

www/static/sw.js

@@ -0,0 +1,74 @@
+const VERSION = 1
+const CACHE = `cache:obolus:${VERSION}`
+
+const getCache = () => self.caches.open(CACHE)
+
+const getPathFromUrl = url => url.replace(/^https?:\/\/[^\/]+/, '')
+
+const _default = {
+    ttl: 24 * 60 * 60,
+    methods: ['GET'],
+}
+
+const NetworkFirst = () => event => new Promise(async (resolve, reject) => {
+    const cache = await getCache()
+    try {
+        const response = await fetch(event.request)
+        if (_default.methods.includes(event.request.method))
+            cache.put(event.request, response.clone())
+        resolve(response)
+    } catch (e) {
+        const cached = await cache.match(event.request)
+        resolve(cached)
+    }
+})
+
+const NetworkOnly = () => event => new Promise(async (resolve, reject) => {
+    const cache = await getCache()
+    const response = await fetch(event.request)
+    cache.put(event.request, response.clone())
+    resolve(response)
+})
+
+const CacheFirst = () => event => new Promise(async (resolve, reject) => {
+    const cache = await getCache()
+    const cached = await cache.match(event.request)
+    if (cached) resolve(cached)
+    else {
+        const response = await fetch(event.request)
+        cache.put(event.request, response.clone())
+        resolve(response)
+    }
+})
+
+const CacheOnly = () => event => new Promise(async (resolve, reject) => {
+    const cache = await getCache()
+    const cached = await cache.match(event.request)
+    resolve(cached)
+})
+
+const Rolling = () => event => {
+}
+
+const routes = [
+    {
+        match: /^\/api\//,
+        handler: NetworkFirst(),
+    },
+    {
+        match: /^\/static\/icons\//,
+        handler: CacheFirst(),
+    },
+    {
+        match: /.*/,
+        handler: NetworkFirst(),
+    },
+]
+
+self.addEventListener('fetch', event => {
+    const path = getPathFromUrl(event.request.url)
+    const route = routes.find(route => route.match.test(path))
+    if (route) {
+        event.respondWith(route.handler(event))
+    }
+})