Magento 2 cookies not working when all cache is enabled

Question

In an observer I'm setting a cookie like this:

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$cookieManager = $objectManager->get('Magento\Framework\Stdlib\CookieManagerInterface');

$cookieManager->setPublicCookie('myvar', $myVar);

Everything is working when Full page caching is disabled. However, once I enable it, the cookie won't be set.

How can I fix this?

Answer 1

OK. I asked the question on the official GitHub. It is quite normal if you are (like me) trying to access a cookie in a Block.

I found this topic and especially this one and hope this will help.

Answer 2

I managed to set the cookie the same way magento sets it for store by using plugins.

See file for plugin definition: vendor/magento/module-store/etc/di.xml:265

<type name="Magento\Framework\App\FrontController">
    <plugin name="storeCookieValidate" type="Magento\Store\Model\Plugin\StoreCookie" sortOrder="10"/>
</type>

And here you have the actual cookie set on beforeDispatch() vendor/magento/module-store/Model/Plugin/StoreCookie.php:69