self.addEventListener('fetch', function(e) {
    console.log('[ServiceWorker] Fetch', e.request.url);
    if (cdnToCache.find((element)=>{return e.request.url.indexOf(element) === 0;})) {
        e.respondWith(
            caches.match(e.request.url).then(function(response) {
                if (response){
                    return response
                }else{
                    return fetch(e.request)
                            .then(function(response) {
                                return caches.open(cacheCdnName).then(function(cache) {
                                    cache.put(e.request.url, response.clone());
                                    console.log('[ServiceWorker] Fetched&Cached Data');
                                    return response;
                                });
                            })
                }
            })
        );
    } else {
        e.respondWith(
            caches.match(e.request).then(function(response) {
                return response || fetch(e.request);
            })
        );
    }
});