constructor(private data: GetDataService) {

     if ('serviceWorker' in navigator) {
        navigator.serviceWorker
            .register('/assets/sw.js')
            .then( registration => {
                // Registration was successful
                console.log('ServiceWorker registration successful with scope: ', registration.scope);
                this.data.getData()    // uses http.get.
                    .subscribe(data => {
                        // ...
                    });

            }).catch(function(err) {
                // registration failed :(
                console.log('ServiceWorker registration failed: ', err);
            });
    }

console.log('sw.js - 1')

var CACHE_NAME = 'af-cache-v2';
var urlsToCache = [
  '/',
  '/assets/restos-af2015.json'
];

self.addEventListener('install', function(event) {
  ...
});

self.addEventListener('activate', function(e) {
  ...
});

self.addEventListener('fetch', function(e) {
  console.log('[ServiceWorker] Fetch', e.request.url);
  e.respondWith(
    caches.match(e.request).then(function(response) {
      return response || fetch(e.request);
    })
  );
});