[Experimental] Disable preprocessing for gtag.ajax.js, to facilitate GDPR/non-GDPR variations

Patch attached.

@jedihe thanks for the post! COOKiES maintainer here.

Please check the code at:
https://git.drupalcode.org/project/cookies/-/blob/1.2.x/modules/cookies_...

Have you enabled that submodule and are you using the latest COOKiES version?

The change from the patch here should NOT be required, as we set the preprocess to false in COOKiES. Could you please elaborate if that doesn't work?

Thanks for your suggestion, @Anybody!

Yes, we're using cookies_gtag 1.2.11. A quick comparison of the local install vs. cookies_gtag.module-1.2.x showed cookies_gtag_js_alter() to be identical.

So, for us, it's not enough what is done in cookies_gtag_js_alter(), only by using the patch in #2 we got to fix the error.

Thanks @jedihe, did you take a look at the code?

I really don't get the difference. Can you tell what it is? Our code should exactly do the same already as your patch does. What am I missing?
Could you perhaps debug that, so that we can fix this in COOKiES? That would be awesome.

Thanks for the quick follow-up :).

The difference is that the js_alter hook in COOKiES is only setting preprocess to false when a certain condition is met; as long as that condition is true for all visitors, it should be no problem. In our case, we want to handle users in two groups: one with COOKiES enabled, one without.

Although I didn't yet do a deep analysis to fully confirm, the above is what should explain the issue we were seeing.

I think this change record is relevant for this discussion: https://www.drupal.org/node/2888767 → . In particular:

In general, hook_css_alter() and hook_js_alter() may now be called from a separate HTTP request from the one rendering the HTML (this was already the case with some contributed modules), and as such cannot vary on all information from the request such as route.