I just noticed on one of my sites that some download links to PDF, zip, and other assets had an almost total drop in download events in Google Analytics after a recent Yoast Google Analytics for WordPress plugin update. So I began to troubleshoot …
I was then able to monitor the console and see the Google Analytics pageview event fire, however, I did not see the “download” event fire. I was stuck.
When I viewed the source code of my site, I could see that only the download & outbound links with fully-qualified URLs had onclick handlers attached in order to properly fire _trackEvent() attached, and not the links with relative URLs. After updating my page to use the full URLs, those download links immediately began working again, and I was able to see the event fire in the debug console as well as show up in my GA real-time event tracking.
Success! The root cause of this seems to be a bug in the Yoast plugin as GA should allow any text string – relative URL or not – as an event action, and I’ve reported the issue to them in the WordPress forums. It seems that the “link sanitization” feature that rewrites relative URLs with full URLs was added to the plugin in v4.0.2, however since then it has stopped adding the click event handlers to links with relative URLs.
The moral of the story is that relative links rarely come back and bite you, and they are so convenient when moving content and code between environments. But the cost of that convenience is a very small chance that not using a full URL will break something, and it may or may not fit your individual tolerance for risk.
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