Avoid enqueuing duplicate consent update commands on page load.

[techanvil]

Feature Description

At present, when using Complianz for the cookie banner, two duplicate consent update commands are enqueued on page load:

This is because we enqueue the update command in response to the wp_consent_type_defined event as well as conditionally on page load via DOMContentLoaded if window.waitfor_consent_hook is not set. This approach roughly follows the example of the WP Consent API integration example plugin.

site-kit-wp/includes/Core/Consent_Mode/Consent_Mode.php

Lines 157 to 165 in fe57e17

	document.addEventListener(
	'wp_consent_type_defined',
	updateGrantedConsent
	);
	document.addEventListener( 'DOMContentLoaded', function () {
	if ( ! window.waitfor_consent_hook ) {
	updateGrantedConsent();
	}
	} );

Complianz always fires the wp_consent_type_defined event, but it only defines waitfor_consent_hook when Geo IP is enabled (which is only available in the paid version).

It's possible the same could apply to other CMPs too, although Complianz is the only one we've seen so far which dispatches the wp_consent_type_defined event.

We should consider whether to avoid allowing duplicate consent update commands to be queued in this manner; it's essentially harmless, but it would be nice to reduce clutter in the dataLayer array.

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Do not alter or remove anything below. The following sections will be managed by moderators only.

Acceptance criteria

• Only one consent update command should be queued regardless of if the wp_consent_type_defined event is called.

Implementation Brief

The goal here is to only trigger the consent update if any of the consent settings have changed.

• Update includes/Core/Consent_Mode/Consent_Mode.php:
  • Create a new window variable window._googlesitekitConsents.
  • Update updateGrantedConsent function:
    • Before the gtag call, use Object.find to compare window._googlesitekitConsents with consentParameters, if any keys are found to mismatch, then continue to call gtag, if all keys match, do not call gtag.
    • After the gtag update consent is called, set window._googlesitekitConsents to the value of consentParameters.

Test Coverage

• Add test coverage to assets/js/consent-mode/consent-mode.test.js to confirm the update command will not be send twice in the above case.

QA Brief

• Enable Consent Mode in the plugin Admin settings.
• Install and Activate the WP Consent API plugin.
• Install and Activate the Complianz plugin.
• Setup a plugin like GA Debug so you can see events that are triggered.
• Load a page in an incognito window to simulate a new user visiting the site.
• Accept permissions in the consent banner.
• Refresh the page - when the page loads this time, the page should only trigger consent update once.

Changelog entry

• Update Consent Mode to prevent enqueuing duplicate consent commands on page load.

[eugene-manuilov]

AC ✔️

[eugene-manuilov]

IB ✔️, but the estimate is too high, i'll update it to 3.

[mohitwp]

QA Update ✅

• Tested on dev environment.
• Verified that on latest environment duplicate consent update commands loads on page load and on dev environment now only one command gets load.
• Tested using complianz plygin.
• Tested for both Accept and deny actions.
• Verified only one consent update command queued regardless of if the wp_consent_type_defined event is called.

Latest environment -

Dev environment -

When user accept the permissions

Recording.1190.mp4

When user deny the permissions

Recording.1191.mp4