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 something similar to a library, and then open-sourcing it for the community to help out with or to download locally for their own purposes.
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 hit type pageview is received successfully by the Google Analytics endpoint.
After the recent release of Custom Templates for Google Tag Manager, my mind has been occupied by very little else. However, I have a nagging feeling that due to how involved the feature set is, there's still a lot of demystifying that needs to take place before templates are fully embraced by the GTM user base. In this article, I want to show you a concrete example of template creation. It's going to be much more ambitious than the simple walkthrough I explored in the main guide.
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 sequencing, and the other is a scenario where you want to run some custom code that should access the latest value of the Data Layer variable at a moment in time after the tag has already fired.
Updated 1 October 2019 With ITP 2.3 it looks like Safari is reducing the usefulness of localStorage as well, so this solution should not be considered future-proof. The only stable way to persist client-side data at the moment seems to be HTTP cookies. Updated 7 March 2019 - Added some extra caveats to this solution. Also, be sure to read my article on ITP 2.1, which has far more detail on what Intelligent Tracking Prevention is and how to work with it.
A recurring question in the Google Tag Manager communities (e.g. product forums) is how to use an Enhanced Ecommerce dataLayer object with the Facebook pixel code? It's a common question since running a Facebook conversion pixel on a site that also collects data from the store into Google Analytics’ Enhanced Ecommerce reports is probably a very typical scenario. Side note: Since Google+ is about to go the way of the dodo, I've created an archive of the entire community which you can browse and make text searches against.