download generated file client side

var blob = new Blob([JSON.stringify(photos)], {"type": "application/json"});
var link = document.createElement("a");
if(link.download !== undefined) {
  link.setAttribute("href", window.URL.createObjectURL(blob));
  link.setAttribute("download", "photos1.json");
 }
else {
  link.setAttribute("href", "http://www.example.com/export");
}
link.click();