Google gtag.js script did not render

[KarlBishop]

I've added an AdWords Conversion ID and switched on Google gtag.js Enabled on various sites in a multisite Craft instance.

When I look at the source code of a page, I see <script>/* Google gtag.js script did not render */</script> in the head.

I had a look at previous related issues #942 and #944 but didn't find a way to fix my problem yet:

• I don't see an Error rendering template string message, as mentioned in issue 942
• The Script Template and Body Script Template are unmodified from default

Any ideas on what might be causing this or how I could troubleshoot?

Versions

• Plugin version: 3.4.32 (was 3.4.30 when first encountered)
• Craft version: 3.7.44 (was 3.7.42 when first encountered)

Screenshot

[khalwat]

@KarlBishop can you check your web.log? There should be more detail there on exactly why it couldn't render that template.

You can try diagnosing it also by temporarily replacing the Body Script Template with a simple Twig expression or the like, to see if that renders.

On the surface, I don't see anything wrong with it however... and I'm able to enable gtag locally here without issue.

[KarlBishop]

I checked my web.log and there weren't any errors.

Tried outputting simple Twig in the Script Template and Body Script Template and this worked fine.

Then did some testing of the default code and found my issue was caused because gtagProperty was evaluating as blank in the first line of both templates.

Fixed the problem by replacing this:

{% set gtagProperty = googleAnalyticsId.value ?? googleAdWordsId.value ?? dcFloodlightId.value ?? null %}

With this:

{% set gtagProperty = googleAnalyticsId.value ??? googleAdWordsId.value ??? dcFloodlightId.value ??? null %}

[khalwat]

Interesting. So those values are not null, they are empty strings?

[KarlBishop]

Seems so, yes.

E.g. if I add the following in the Script Template:

{% if googleAnalyticsId.value is defined %}
    console.log("googleAnalyticsId.value is defined");

    {% if googleAnalyticsId.value is null %}
        console.log("googleAnalyticsId.value is null");
    {% else %}
        console.log("googleAnalyticsId.value is NOT null");
    {% endif %}

    {% if googleAnalyticsId.value is empty %}
        console.log("googleAnalyticsId.value is empty");
    {% else %}
        console.log("googleAnalyticsId.value is NOT empty");
    {% endif %}

    {% if googleAnalyticsId.value == "" %}
        console.log("googleAnalyticsId.value is an empty string");
    {% else %}
        console.log("googleAnalyticsId.value is NOT an empty string");
    {% endif %}

{% else %}
    console.log("googleAnalyticsId.value is NOT defined");
{% endif %}

Then the console output is:

googleAnalyticsId.value is defined
googleAnalyticsId.value is NOT null
googleAnalyticsId.value is empty
googleAnalyticsId.value is an empty string

[khalwat]

So it looks like this was already fixed a bit over a year ago:

https://github.com/nystudio107/craft-seomatic/blob/develop/src/templates/_frontend/scripts/gtagBody.twig

https://github.com/nystudio107/craft-seomatic/blob/develop/src/templates/_frontend/scripts/gtagHead.twig

Committed on Mar 31, 2021: https://github.com/nystudio107/craft-seomatic/commit/83dea919197f6464e214436bd20e28b3d509361f

It doesn't auto-update the scripts, because it's possible you might have changed them, and we don't want to blow away any changes you've made.

[KarlBishop]

Ahh ok, in that case I find this is a bit unintuitive - I wouldn't have guessed that my template code was over a year out-of-date because I only created the site 4 months ago and had only just enabled the Google gtag.js settings last week.

My expectation would be that, if I'm only just activating the template editor box for the first time now, then it would be using the current default.

I'm guessing my issue was caused because:

• gtagBody and gtagHead are saved in the database for every Site, even when the Google gtag.js has never been enabled?
• when creating a new Site, gtagBody and gtagHead are populated by copying from the default Site rather than from the templates in the vendor folder?

I might add a feature request for ways to avoid this type of confusion (even if only for myself).

[khalwat]

Yeah the defaults are in place as soon as SEOmatic is installed. Flipping the lightswitch on just shows you the settings you can edit.

The only way around it that I can think of would be a checksum on the template code, and if they match, we can safely update. Unfortunately this doesn't handle the case of where you make a minor change to the template code... because then it wouldn't update it.

The best thing is obviously to not make any errors to begin with (which is really hard to do given the complexity of the system). After that, I think probably it's best to have a consistent mental model that anything the user can edit in the CP won't be updated by future updates.

I'm open to discussion on that though!