FetchJS addSubscriber possible problem


I was following this guide: https://www.fusetools.com/developers/guides/fusejs/fetchjson and it kept crashing. So I changed it to this:

    data.addSubscriber(function() {
      // Assuming description is a member of the returned JSON
      // object from the url

      debug_log("got some data " + data);
      //debug_log("Got some data: " + data.value.arne);

And it gave the following output:

Output: got some data (observable) 
Output: got some data (observable) {"arne":"arnemann"}

So it will be called to times. One time with undefined in data or data.value. Is this the correct behaviour?

Also it seems like it doesn’t parse the json, but rather gives me the whole json-string in data.value, and nothing in data.value.arne