Implementation Tips: OneTrust GTM Tag and Custom Cookie Settings Button

Cover Image for Implementation Tips: OneTrust GTM Tag and Custom Cookie Settings Button

TLDR;

In this post, we cover how to:

  1. Compose a GTM tag for OneTrust so that it works in production and all test environments
  2. Implement a custom cookie preferences button using a General Link field in Sitecore and rendering it in Next.js

GTM Tag Setup

I was surprised to find that there was no documentation with a specific example of how to properly code the tag so that it works in all environments.

The solution is to set the data-domain-key based on the current hostname. Using a Custom HTML Tag, this is trivial:


_19
<script>
_19
(function() {
_19
// OneTrust Cookies Consent Notice for www.acme.com
_19
_19
var domainScriptValue = (window.location.hostname === 'www.acme.com')
_19
? 'xxxx' // production
_19
: 'xxxx-test'; // anything other than production
_19
_19
var otScript = document.createElement('script');
_19
otScript.type = 'text/javascript';
_19
otScript.charset = 'UTF-8';
_19
otScript.src = 'https://cdn.cookielaw.org/scripttemplates/otSDKStub.js';
_19
otScript.setAttribute('data-domain-script', domainScriptValue);
_19
_19
document.head.appendChild(otScript);
_19
_19
window.OptanonWrapper = function() { };
_19
})();
_19
</script>

The default green floating cookie preferences button that ships with OneTrust is a bit goofy, and it obstructs the viewport on smaller screen sizes or when viewing a site with a high level of zoom.

You can disable the default button in favor of a custom button that is triggered via a JavaScript call to Optanon.ToggleInfoDisplay().

The footer is a good place for a cookie preferences button, given that the functionality is rarely used. You probably already have a Sitecore component for your footer links which leverage a series of General Link fields, which support JavaScript.

General Link with JavaScript

Now we have a new problem to solve. Sitecore always suffixes the JavaScript with ;return false; which will throw errors into your console when clicking the button and cause the functionality not to work:


_1
<a href="javascript:Optanon.ToggleInfoDisplay();return false;">Cookie Settings</a>

In pure XM Cloud-friendly fashion, let's customize how the link is rendered in the head. One way to do this in headless applications such as Next.js is to modify the link field value before rendering it. You might create a custom component that wraps the Link component that ships with @sitecore-jss/sitecore-jss-nextjs:


_20
import { Link } from '@sitecore-jss/sitecore-jss-nextjs';
_20
_20
const CustomLinkWithJavaScriptSupportComponent = (props) => {
_20
let linkData = props?.fields?.item?.fields?.link?.value;
_20
_20
if (linkData?.linktype === 'javascript') {
_20
linkData.href = linkData.href?.replace(';return false;', '');
_20
}
_20
_20
return (
_20
<Link
_20
field={{
_20
...props.item.fields.link,
_20
value: linkData
_20
}}
_20
/>
_20
);
_20
};
_20
_20
export default CustomLinkWithJavaScriptSupportComponent;

After which, your link will appear like so:


_1
<a href="javascript:Optanon.ToggleInfoDisplay()">Cookie Settings</a>

I also shared this code as an answer on SSE: https://sitecore.stackexchange.com/a/39036/946

Stay hungry,

-MG


More Stories

Cover Image for Tips for Forms Implementations

Tips for Forms Implementations

> And other pro tips

Cover Image for Script: Boost SIF Certificate Expiry Days

Script: Boost SIF Certificate Expiry Days

> One simple script that definitely won't delete your system32 folder

Cover Image for Ideas For Docker up.ps1 Scripts

Ideas For Docker up.ps1 Scripts

> Because Docker can be brittle

Cover Image for Super Fast Project Builds with Visual Studio Publish

Super Fast Project Builds with Visual Studio Publish

> For when solution builds take too long

Cover Image for JSS: Reducing Bloat in Multilist Field Serialization

JSS: Reducing Bloat in Multilist Field Serialization

> Because: performance, security, and error-avoidance

Cover Image for Tips for Applying Cumulative Sitecore XM/XP Patches and Hotfixes

Tips for Applying Cumulative Sitecore XM/XP Patches and Hotfixes

> It's probably time to overhaul your processes

Cover Image for Early Returns in React Components

Early Returns in React Components

> When and how should you return early in a React component?

Cover Image for On Sitecore Development

On Sitecore Development

> Broadly speaking

Cover Image for NextJS: Access has been blocked by CORS policy

NextJS: Access has been blocked by CORS policy

> CORS is almost as much of a nuisance as GDPR popups

Cover Image for On Mentorship and Community Contributions

On Mentorship and Community Contributions

> Reflections and what I learned as an MVP mentor

Cover Image for Azure PaaS Cache Optimization

Azure PaaS Cache Optimization

> App Services benefit greatly from proper configuration

Cover Image for Tips for New Sitecore Developers

Tips for New Sitecore Developers

> If I had more time, I would have written a shorter letter

Cover Image for Year in Review: 2022

Year in Review: 2022

> Full steam ahead

Cover Image for NextJS/JSS Edit Frames Before JSS v21.1.0

NextJS/JSS Edit Frames Before JSS v21.1.0

> It is possible. We have the technology.

Cover Image for How to Run Old Versions of Solr in a Docker Container

How to Run Old Versions of Solr in a Docker Container

> Please don't make me install another version of Solr on my local...

Cover Image for NextJS: Unable to Verify the First Certificate

NextJS: Unable to Verify the First Certificate

> UNABLE_TO_VERIFY_LEAF_SIGNATURE

Cover Image for Security Series: App Service IP Restrictions

Security Series: App Service IP Restrictions

> How to manage IP rules "at scale" using the Azure CLI

Cover Image for Sitecore Symposium 2022

Sitecore Symposium 2022

> What I'm Watching 👀

Cover Image for NextJS: Short URL for Viewing Layout Service Response

NextJS: Short URL for Viewing Layout Service Response

> Because the default URL is 2long4me

Cover Image for Content Editor Search Bar Not Working

Content Editor Search Bar Not Working

> Sometimes it works, sometimes not

Cover Image for Symposium 2022 Reflections

Symposium 2022 Reflections

> Sitecore is making big changes

Cover Image for JSS + TypeScript Sitecore Project Tips

JSS + TypeScript Sitecore Project Tips

> New tech, new challenges

Cover Image for Don't Ignore the HttpRequestValidationException

Don't Ignore the HttpRequestValidationException

> Doing so could be... potentially dangerous

Cover Image for Critical Security Bulletin SC2024-001-619349 Announced

Critical Security Bulletin SC2024-001-619349 Announced

> And other scintillating commentary

Cover Image for SPE Script Performance & Troubleshooting

SPE Script Performance & Troubleshooting

> Script never ends or runs too slow? Get in here.

Cover Image for Troubleshooting 502 Responses in Azure App Services

Troubleshooting 502 Responses in Azure App Services

> App Services don't support all libraries

Cover Image for Hello World

Hello World

> Welcome to the show

Cover Image for On Sitecore Stack Exchange (SSE)

On Sitecore Stack Exchange (SSE)

> What I've learned, what I see, what I want to see

Cover Image for Add TypeScript Type Checks to RouteData fields

Add TypeScript Type Checks to RouteData fields

> Inspired by error: Conversion of type may be a mistake because neither type sufficiently overlaps with the other.