Google跟踪代码管理器dataLayer推送未存储对象

Question

I've read through several SO posts and the docs and api . My understanding is that the dataLayer global object should behave Array-like and increase in size when you .push() an event object into it. According to the screenshot here .

My dataLayer object does not grow like this. It exists on the window and I can run

dataLayer.push({'event': 'trackEvent'});

without error, except that it does not increase the size of dataLayer.

Other than the array growing and how else can I tell if .push() is working or not?

Should the browser perform an xhr request when events are detected?

Does the GTM script perform client-side logic based off of GTM settings (tags/triggers) before sending them to google? ie, are the events not pushing because they don't pass validation.

Does it matter if I'm testing this on localhost?

How do I fix this?

Answer 1

The datalayer is an array, so yes, it should behave like an array. The individual items are objects.

It should not perform xhr requests, since GTM is bundled and downloaded in toto to your page, so xhr would not be needed.

GTM events are by themselves never send to Google (they are only used to trigger tags, which then might send data to Google. They not automatically map to Google Analytics events). They are not validated, GTM just amends the push method to see if the arguments contain the key "event" (at which point the internal state of the GTM script is updated with the new values).

It seems that something happens to your datalayer after GTM is loaded (you have the start event, but no gtm.dom or gtm.load) so you might want to check if datalayer is re-declared after the GTM snippet. But to actually debug the problem it would help if we could see how you embed GTM and set up your datalayer (if there is any chance we could have a glance at your page, or an example page that shows the same problem, that would be very helpful).

Answer 2

My colleague was able to load the preview mode and verify the event pushing into dataLayer. Apparently the duckduckgo extension was preventing the loading of the preview mode task bar.

I'll be opening this as a bug with the DDG team.

For future searchers, you should be able to pull up gtm preview mode pretty easily. You would see network events like in the screenshot.