Deploying Google Marketing Tags Asyncronously through DTM

I had posted previously about how to deploy marketing tags asynchronously through DTM, but Google Remarketing tags add an extra consideration: Google actually has a separate script to use if you want to deploy asynchronously. The idea is, you could reference the overall async script at the top of your page, then at any point later on, you would fire google_trackConversion to send your pixel. However, this is done slightly differently when you need your reference to that async script file to happen in the same code block as your pixel… you have to make sure the script has had a chance to load before you fire that trackConversion method, or you’ll get an error that “google_trackConversion is undefined”.

Below is an example of how I’ve done that in DTM.

//first, get the async google script, and make sure it has loaded
var dtmGOOGLE = document.createElement('SCRIPT');
var done = false;

dtmGOOGLE.setAttribute('src', '//www.googleadservices.com/pagead/conversion_async.js');
dtmGOOGLE.setAttribute('type','text/javascript');

document.body.appendChild(dtmGOOGLE);
dtmGOOGLE.onload = dtmGOOGLE.onreadystatechange = function () {
 if(!done && (!this.readyState || this.readyState === "loaded" || this.readyState === "complete")) {
 done = true;
 callback();

 // Handle memory leak in IE
 dtmGOOGLE.onload = dtmGOOGLE.onreadystatechange = null;
 document.body.removeChild(dtmGOOGLE);
 }
};

//then, create that pixel
function callback(){
 if(done){ 
 /* <![CDATA[ */
 window.google_trackConversion({
 google_conversion_id : 12345789,
 google_custom_params : window.google_tag_params,
 google_remarketing_only : true
 });
 //]]> 
 }
}