Synchronous GM_xmlhttpRequest acting asynchronously?

Question

I\'m trying to get a GM_xmlhttpRequest call to behave synchronously, but I can\'t get it to work like I expect:

function myFunction (arg) {
             


        

Answer 1

Just stumbled upon this topic in Google.

Synchronous GM_xmlhttpRequest RETURN the result instead of executing it in the onload-callback.

So this would be right:

var details = GM_xmlhttpRequest({
  method:"GET",
  url:"http://site.com/sample/url",
  synchronous: true
});
a = details.responseText;

You create the var "a" in the beginning, never fill it and return it. Therefore, it is undefined.