My department has analytic rule conditions in DTM that trigger events based on particular classes or custom data attributes. I'm concerned that if our dev team makes a change that would break the rule, we wouldn't find out until it's discovered that the metric is no longer tracking.
We're trying to future proof our scripts to allow for changing conditions (eg: using regex for changing class names &/or functions to traverse the DOM to find a condition without it needing to be hardcoded), but I thought someone here might have experience with this type of issue. How was it handled at your company?
**EDIT:**I'm exploring using custom Data Elements within DTM that are created with javascript that has multiple conditions for traversing the DOM in ways we've identified. So a sort of data layer that's controllable by my team.
Note: This isn't really an actual coding question; more of [analytics/marketing tag] coding principles/best practices. So I'm not entirely sure this question belongs on SO (maybe one of the other stack exchange sites, perhaps superuser.com?). But I'll answer here anyways.
TL;DR - You need to get site devs involved and have them take on some level of initial and ongoing ownership of it.
Tag managers sell themselves on being able to deploy tags without getting site devs involved, and many times this works out in the short term. But in my experience, this kind of passive deployment just doesn't work out in the long term, especially for websites that have active and regular changes over time.
In my experience, the only way to effectively help prevent site devs from inadvertently breaking the tracking from this, is to include the site devs in the deployment and make them take ownership of it on some level, so that it is something they are aware of within their own system/flow.
Sometimes it is as easy as having designated classes or attributes added to html tags on the page. For example, you can write a spec for the site devs to add a
data-analytics='true'to any header, footer, CTA links on a given page, and tell the site devs this is something they need to keep as part of their workflow whenever they make changes to the site.For more complicated things, you could spec for them to do something like broadcast a custom event for you to listen for. For example, maybe you have a purchase confirmation page and right now you have code in DTM to trigger based off the URL, or scrape the page for details about the purchase to push to tags. Instead, create a spec with instructions for the devs to put that in a data layer object and push to a custom event, and then create an event based rule for it.
The overall theme here is to create a spec document for all the things you want to be able to track on the website, that you know you can't reliably passively track without it breaking sooner or later, and hand the document to the devs and tell them they need to make it a part of their flow when making changes to the site. Bonus points if you can get them to loop you in whenever changes are going to be made and pushed to production, that you may go to your dev/qa version of your site to test to make sure your tracking still looks good.
The overall overall theme here is in order to prevent site devs from breaking your tracking, you need to be more proactive about making them and keeping them aware of your tracking, and in practice, this usually means putting some of the code work on their plate to own, so it's something in their history, in front of their face to see and know about. Because it is a lot easier for a dev to take notice of a
data-analytics='true'in the header nav links they are about to restructure, than knowing hey, some piece of code in DTM relies on this current structure.. something that's not more directly in front of their face in their own code editor/environment.Yes, actually accomplishing the above is often easier said than done. But it is the reality of the situation. Passively tracking things in a tag manager rarely works out for longer term stuff, short of "every page" tags that have little or no customization requirements at all.
I tell you from my own experience of over 10 years of working in the digital marketing and analytics industry, specifically with implementation, I have seen this time and time again. Too many times to count. Clients often want to and actually take the easier route of leaving the site devs out of the loop, all tracking requirements done solely through whatever the tag manager is capable of doing.
I've seen setups with hundreds of rules with trigger conditions based off scraping the page for some id or class, or some complex css selector dependent on 5 levels of html structure not changing. Or some random cookie you just assume means what you think it means. And you're spending more and more of your time playing whack-a-mole trying to re-adjust/fix individual rules/selectors as the next random change happens, and then one day comes a full site redesign and it's a nuclear bomb on all your tracking efforts.
And time and time again, without fail, eventually they wind up asking exactly what you've asked here, kicking themselves in the arse for the time and money they spent already on it for that "quick win", because nobody is confident in the data and they're wondering why they are allocating money/resources on tracking if it's just a bunch of trash, broken, pothole data. And the solution to it has always been "site dev awareness".
If it helps.. one card I sometimes play if I have a hard time convincing the dev team or other powers-that-be to jump on that bandwagon, is to point out that one of the biggest reasons for tracking websites is to help companies determine whether or not it's worth investing money in said website. If they can't determine that, then they may not be so inclined to do so, which means their need to even have a site dev team may also decline. To be more candid: it is something that helps justify their job.