GTM, Consent mode v2 the data layer & GA4

February 20, 2025

815 words | 5 min read.

Documentation Post processing Analytics Data layer GA4 GTM

In this part we explore how to integrate GTM, GA4, Consent Mode v2 and enchanced e-commerce events for GA4 with the headless Woo setup and superfunky theme on Netlify.

Configuring Netlify’s post processing script injection

First of all we need to add some scripts to the post-processing part in this location:

Go to: https://app.netlify.com/sites/yoursite/configuration/deploys#post-processing

Replace /yoursite/ with the actual name of Your project.

You need to set up the following scripts in the correct order from 1 to 4 in the correct place (body or head) in the netlify admin.

1. TCF – Enabled tcf support for Google tag – before </head>
2. DCV – Default consent values – before </head>
3. GTM Script – before </head>
4. GTM noscript – before </body>

Here you can find the contents of each required code for the integration to work:

TCF code
<!-- Enabled tcf support for Google tag -->
<script>
    window ['gtag_enable_tcf_support'] = true;  
</script>

<!-- DCV code sets Consent Mode v2 initial values -->
<script>
    window.dataLayer = window.dataLayer || [];
    function gtag() {
        dataLayer.push(arguments);
    }
    gtag("consent", "default", {
        ad_storage: "denied",
        ad_user_data: "denied", 
        ad_personalization: "denied",
        analytics_storage: "granted",
        functionality_storage: "granted",
        personalization_storage: "granted",
        security_storage: "granted",
        wait_for_update: 2500,
    });
    gtag("set", "ads_data_redaction", true);
    gtag("set", "url_passthrough", true);
</script>

<!-- Google Tag Manager -->
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-XXX');</script>
<!-- End Google Tag Manager -->

<!-- Google Tag Manager (noscript) -->
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXX"
height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
<!-- End Google Tag Manager (noscript) -->

Once configured move to the Google Tag manager configuration.