#gtmtips

In Google Tag Manager, the Custom JavaScript variable is an anonymous function with a return statement. It does not take any parameters, and by default it’s impossible to pass any parameters to it, because the Custom JS variable is simply resolved to whatever value the function returns. If it returns a number, for example, passing a parameter to it would make no sense and would result in a…

One of Google Tag Manager’s oldest and most reliable features is that it freezes the state of Data Layer variables to the moment when the trigger event occurred. Thus, any tags firing on this trigger (and any variables resolved on this trigger event) will always have access to the same value of each Data Layer variable. However, there are situations where this is not a good thing. One is tag…

One of my pet peeves about Google Analytics has to do with nomenclature. For example, a User isn’t really a user but a browser instance, and Direct traffic isn’t necessarily “direct” at all, but rather just traffic that has no discernible source. But being so invested in content analytics, my biggest gripe has to do with Pageviews. A Pageview in Google Analytics is collected when a hit with the…

When Custom Templates were released in Google Tag Manager, many of us active in the GTM communities started doing two things: 1) creating our own custom templates, and 2) waiting patiently for Google to release a “gallery” or “library” for distributing these community contributions. While I have full faith in the latter happening some time in the future, I thought it would be fun to create…

With Intelligent Tracking Prevention, the Safari browser is on a crusade against cross-site tracking. One of the most obvious and long-standing ways to battle cross-site tracking has been to block third-party cookies in the web browser, and this is exactly what Safari does by default. However, Google Tag Manager’s Preview mode relies on a third-party cookies, so that it can serve you the draft…

It’s been a while since I’ve last written a bona fide Google Tag Manager trick, so here comes. This was inspired by Bart Gibby’s question in Measure Slack. The purpose is to fetch the latest currency exchange rates from the exchangeratesapi.io service, cache them using sessionStorage, and push the results into dataLayer. From dataLayer, they can then be utilized in Custom JavaScript variables and…

A surprisingly common question in forums and communities seems to be why the built-in Click variables show up as undefined in Google Tag Manager’s Preview mode, even if you click around the site. In this article, I’ll walk you through some of the reasons why this might happen. X The Simmer Newsletter Subscribe to the Simmer newsletter to get the latest news and content from Simo Ahava into…

Google Tag Manager now lets you add unit tests directly to your custom templates. This is useful, since it allows you to control the code stability of your templates, especially if you’ve decided to share those templates with the public. I recently shared a general guide for how template tests work, but I wanted to expand the topic a little, and share with you two walkthroughs of custom template…