Waiting for mixpanel JS lib to be ready so I can get users distinct_id

Question

We want to use MixPanel to capture events on our site and I'm trying to get hold of the users distinct id, so I'm using the following code snippet:

$(document).ready(function($){  
    console.log("We have distinct id");
    console.log(mixpanel.get_distinct_id());
});

This causes an error saying 'undefined is not a function' when attempting to get the distinct id.

I've checked in the debugger and can confirm that the mixpanel object does not have a get_distinct_id method, However if I wait until the page has loaded and then evaluate mixpanel.get_distinct_id() in the console, I get the distinct id without problem.

I can only guess that the mixpanel object hasn't completed initialisation yet. Is there a callback or an event that I can use to know once the mixpanel object will be able to tell me the users distinct_id?

Answer 1

From a Mixpanel article:

"[...] pass a config object to the mixpanel.init() method with a loaded parameter and a callback function that will execute immediately after our library has finished loading. Inside the callback function, you can use the get_property() and get_distinct_id() methods and ensure that they'll only execute after the library has finished loading."

mixpanel.init('Project Token', {'loaded':function() {
    var distinct_id = mixpanel.get_distinct_id()}
});

Source: How to prevent get_distinct_id & get_property from returning undefined

Answer 2

I found a code snippet here: https://gist.github.com/calvinfo/5117821, credit to https://gist.github.com/calvinfo which looks like this:

$(document).ready(function() {
  if ($("#mixpanel_distinct_id").length > 0) {
    var interval = setInterval(function () {
      if (window.mixpanel.get_distinct_id) {
        $("#mixpanel_distinct_id").val(window.mixpanel.get_distinct_id());
        clearInterval(interval);
      }
    }, 300);
  }
});

Basically this allows you to check every 300 milliseconds whether the mixpanel object has completed initializing and the get_distinct_id function is available.