php - XMLHttpRequest within service worker -

i'm trying create push notification system on chrome. have php fetches data mysql , echoes json, i'd call function getjsoncode() it's activated when push notification arrives , reads json data.

within service worker i've created standards functions. problem when create getjsoncode xmlhttprequest tells me it's not defined

self.addeventlistener('install', function(event) {   self.skipwaiting();   console.log('installed', event); }); self.addeventlistener('activate', function(event) {   console.log('activated', event); }); self.addeventlistener('push', function(event) {     console.log('push message', event);   getjsoncode();   ); })  getjsoncode() {   coderequest= new xmlhttprequest();   coderequest.open('get', 'myfilewithjson.php', true);   coderequest.send();   datajson = coderequest.responsetext;   console.log('rispostajson'); } 

is possible call external file within service worker or there kind of limitations? because don't why isn't working

instead of xmlhttprequest, can use new fetch api. xmlhttprequest has been deprecated , not available in service worker scope.

there's example of want achieve in this serviceworker cookbook recipe.