Access previously stored Visitor-level custom variable

Question

In Google Analytics, Visitor-level custom variables are stored in cookies.

I'm looking to store some data in a GA custom variable only if no data has been stored in this slot before, i.e. never overwrite visitor-level custom variables.

Is there any way I can do that, either by testing whether some data has already been stored, or by retrieving the stored value?

There's no _getCustomVar, but is there any way I can do something equivalent without "hacking" into the cookies myself?

Answer 1

There is _getVisitorCustomVar(index).

eg:

_gaq.push(function() {
  var pageTracker = _gat._getTrackerByName(); // Gets the default tracker.
  var visitorCustomVar1Value = pageTracker._getVisitorCustomVar(1);
});

It only works for Visitor level custom var because that's the only one stored client size in the GA cookie __utmz. But that's exactly what you are looking for I guess.

If you want to see if a non-visitor level custom var that has already been set, then you would need to write the logic yourself storing a separate cookie when you set the custom var to be able to retrieve later. But it should be a simple thing and probably better idea than hacking into proprietary cookies.

Answer 2

<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'xxxxxxxxxxxxxxx']);

   _gaq.push(function() {
        var pageTracker = _gat._getTrackerByName();
        var userTypeVar = pageTracker._getVisitorCustomVar(1);
    });

  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>