add pwa restart

view/sw.js

@@ -0,0 +1,28 @@
+//缓存空间名称
+var CACHE_VERSION = 'sw_v1';
+
+var CACHE_FILES = [
+  '/',
+];
+
+self.addEventListener('install', function (event) {
+  event.waitUntil(
+    caches.open(CACHE_VERSION)
+    .then(cache => cache.addAll(CACHE_FILES)
+      .then(() => self.skipWaiting())
+    ));
+});
+
+self.addEventListener('activate', function (event) {
+  event.waitUntil(
+    caches.keys().then(function (keys) {
+      return Promise.all(keys.map(function (key, i) {
+        if (key !== CACHE_VERSION) {
+          return caches.delete(keys[i]);
+        }
+      }));
+    })
+  );
+});
+
+self.addEventListener('fetch', function(event) {});