site/static/js/sw.js

56 lines
1.7 KiB
JavaScript
Executable File

//This is the service worker with the combined offline experience (Offline page + Offline copy of pages)
//Install stage sets up the offline page in the cache and opens a new cache
self.addEventListener('install', function(event) {
event.waitUntil(preLoad());
});
var preLoad = function(){
console.log('[PWA Builder] Install Event processing');
return caches.open('pwabuilder-offline').then(function(cache) {
console.log('[PWA Builder] Cached index and offline page during Install');
return cache.addAll(['/offline.html', '/index.html']);
});
}
self.addEventListener('fetch', function(event) {
console.log('[PWA Builder] The service worker is serving the asset.');
event.respondWith(checkResponse(event.request).catch(function() {
return returnFromCache(event.request)}
));
event.waitUntil(addToCache(event.request));
});
var checkResponse = function(request){
return new Promise(function(fulfill, reject) {
fetch(request).then(function(response){
if(response.status !== 404) {
fulfill(response)
} else {
reject()
}
}, reject)
});
};
var addToCache = function(request){
return caches.open('pwabuilder-offline').then(function (cache) {
return fetch(request).then(function (response) {
console.log('[PWA Builder] add page to offline'+response.url)
return cache.put(request, response);
});
});
};
var returnFromCache = function(request){
return caches.open('pwabuilder-offline').then(function (cache) {
return cache.match(request).then(function (matching) {
if(!matching || matching.status == 404) {
return cache.match('offline.html')
} else {
return matching
}
});
});
};