Saves an octet-stream returned from a REST call as a file

save-js-blob.js

var toSend = {};
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "https://myserver.com/path", true);
xmlhttp.responseType="blob";
xmlhttp.setRequestHeader("Content-Type", "application/json"); 
xmlhttp.overrideMimeType('application/octet-stream'); 
xmlhttp.onload = function() {
	console.log('success');
	console.log(xmlhttp.response);
	window.open(URL.createObjectURL(xmlhttp.response)).focus();
};
xmlhttp.send(JSON.stringify(toSend));