Gtag is not defined ошибка

Short answer

Additionally to the GTM GA App+Web tag, you need to add the following code to have gtag() defined:

<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
</script>

Long answer

According to the official documentation (https://developers.google.com/analytics/devguides/collection/ga4) this is the code you should include in your site:

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=MEASUREMENT_ID"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'MEASUREMENT_ID');
</script>

After inspecting a website with this tag I found GTM has injected that first line, which is enough to make analytics work. But it didn’t add the other lines, some of which effectively defines the gtag global function as a «syntax sugar» for pushing things to the Analytics Data Layer.

Personally, I find this really strange, since using GTM is the most cannonical of adding Google Analytics to a website and it’s by the same company.

answered Feb 21, 2021 at 13:27

dpatryasdpatryas

3593 silver badges12 bronze badges

The cause of the problem has been found. The problem seemed to be that gtag() does not work if the App+Web base setup is done with the GTM App+Web base template tag. Instead, an event should first be pushed to the GTM datalayer, and then the GTM App+Web event template should be used to send the event to Google Analytics.

Lots of thanks Gino (working at Merkle) for fixing the issue!

answered Apr 7, 2020 at 12:48

If you’re using Google Tag Manager, the gtag function doesn’t exist. Follow this guide to create custom events

1. Basically the code you use is: dataLayer.push({event: 'event_name'});

2. Then you setup a tag in GTM for «GA4 event».

3. Use the event name that you want to see in Google analytics.

4. For the trigger, use custom event. Here, in the event name, use the name that you used in your code event_name

answered Oct 31, 2021 at 15:14

植植心植植心

3962 silver badges5 bronze badges

2022 Year answer:

For anyone struggling with using GA4 gtag and GTM (Google Tag Manager) simultaniously in your SPA/Angular/React app, you should do next:

• don’t use built-in GTM’s «Google Analytics: GA4 Configuration» tag configuration
• do use «Custom HTML» GTM tag with exactly that gtag JS code from your Google Analytics, i.e.

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=GA_MEASUREMENT_ID"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'GA_MEASUREMENT_ID');
</script>

After that you can use gtag in your code as you intended to do, all should work. No whole Firebase needed or something. Possibly you will need to have

gtag('config', 'GA_MEASUREMENT_ID', {
  send_page_view: false
});

to disable automatic page_view tracking.

answered Apr 12, 2022 at 14:06

asked Jun 26, 2018 at 11:42

Explanation : Since you are using google tag manager, you have to define the gtag function somewhere. When you followed the tutorial from googleAnalytics they asked you to include some javascript code in your index.html. The problem is when you run your tests you create components without their parents, so the actual index.html file is never loaded neither the javascript code you added. You need to load that code before you run your tests.

How to proceed :
I’d advise you to export that content in a separate file,
then import that file into your index.html

<script src="assets/metrics/gtm.js"></script>

After this go into your Karma.conf.js and below frameworks :[…] add the following :

   files: [
      /* I put my file (containing javascript code) into that path, yours might change */
      { pattern: 'src/assets/**/gtm.js', included: true }
    ],

After this you should be good to simply restart your tests!
Hope it helps someone else!

answered Jul 8, 2020 at 19:11