Using CookieConsent to render conditional HTML in a Twig template

[fabian-st]

I created this very simple extension for Symfony Twig, which allows you to check if a user has given their consent for a specific category:

<?php
namespace App\Twig;

use Symfony\Component\HttpFoundation\RequestStack;
use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;

define('CC_COOKIE', 'cc_cookie'); // must contain the name of the CC cookie

class ConsentExtension extends AbstractExtension
{
    public function __construct(RequestStack $requestStack)
    {
        $this->requestStack = $requestStack;
    }

    public function getFunctions(): array
    {
        return [
            new TwigFunction('consent_exists', [$this, 'consentExists']),
        ];
    }

    public function consentExists($category): bool
    {
        $request = $this->requestStack->getCurrentRequest();
        $ccRaw = $request->cookies->get(CC_COOKIE);

        if ($ccRaw === null) {
            return false;
        }

        $ccCategories = json_decode($ccRaw)->categories;
        return in_array($category, $ccCategories);
    }
}

To use the extension, place it under src/App/Twig/ConsentExtension.php and include it in your services.yaml:

services:
    App\Twig\ConsentExtension:
        arguments:
            $requestStack: '@request_stack'
        tags: [twig.extension]

Afterwards, use it in your Twig templates as follows:

{% if consent_exists('tracking') %}
    <!-- Your HTML goes here -->
{% endif %}

[fabian-st]

Updated to allow checking for category and single service consent:

<?php
namespace App\Twig;

use Symfony\Component\HttpFoundation\RequestStack;
use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;

define('CC_COOKIE', 'cc_cookie');

class ConsentExtension extends AbstractExtension
{
    public function __construct(RequestStack $requestStack)
    {
        $this->requestStack = $requestStack;
    }

    public function getFunctions(): array
    {
        return [
            new TwigFunction('category_consent_exists', [$this, 'categoryConsentExists']),
            new TwigFunction('service_consent_exists', [$this, 'serviceConsentExists']),
        ];
    }

    public function categoryConsentExists($category): bool
    {
        $request = $this->requestStack->getCurrentRequest();
        $ccRaw = $request->cookies->get(CC_COOKIE);

        if ($ccRaw === null) {
            return false;
        }

        $ccCategories = json_decode($ccRaw)->categories;
        return in_array($category, $ccCategories);
    }

    public function serviceConsentExists($service, $category): bool
    {
        $request = $this->requestStack->getCurrentRequest();
        $ccRaw = $request->cookies->get(CC_COOKIE);

        if ($ccRaw === null) {
            return false;
        }

        $ccServices = json_decode($ccRaw)->services;

        if (!property_exists($ccServices, $category)) {
            return false;
        }

        return in_array($service, $ccServices->$category);
    }
}

{% if service_consent_exists('matomo', 'analytics') %}
      <!-- Your HTML goes here -->
{% endif %}