In the HOOK of my project XXX_preprocess I am defining a variable based on a cookie.

My Hook function

function XXXXXX_preprocess(array &$variables) {
if (isset($_COOKIE[personsSearchCookie]) && !empty($_COOKIE[personsSearchCookie])) {
    $personsFilter = explode("-", $_COOKIE[personsSearchCookie]);
    $variables["personsFilter"] = array (
        "filterType" => $personsFilter[0],
        "filterId" => $personsFilter[1]

But in the Twig template, it always gives me the initial value of that variable, it never changes. My Twig code:

Filtering results by [{{ personsFilter.filterType }}]<br />

{% if personsFilter is defined and personsFilter.filterType is defined and personsFilter.filterType is not empty %}
    {% if personsFilter.filterType == "area" %}
        Filtering by Area <br />      
    {% endif %}

    {% if personsFilter.filterType == "office" %}
        Filtering by Office <br />
    {% endif %}
{% else %}
    No filtering
{% endif %}

This should be a cache theme, right?

How can I make so that when my cookie changes, the variable is modified and since twig can access the new value?

In the prepreocess function in all re-loads, the variable change correctly, but, in twig, the variable have bad value.

Thank you!


1 Answer 1


In your question, it wasn't clear how you are defining the render array (a block, a form, etc.) Assuming you are rendering this twig file through a render array, you could add the following to the render array for this particular element to turn off caching of this element:

 '#cache' => [
    'max-age' => 0,

You could get more specific by implementing conditional logic to clear the cache on a certain condition. From the examples module, in the cache_example, we have the CacheExampleForm function createExpiringItem():

* Submit handler to create a new cache item with specified expiration.
public function createExpiringItem($form, &$form_state) {

$tags = array(

$interval = $form_state->getValue('expiration');
if ($interval == 'never_remove') {
  $expiration = CacheBackendInterface::CACHE_PERMANENT;
  $expiration_friendly = $this->t('Never expires');
else {
  $expiration = time() + $interval;
  $expiration_friendly = format_date($expiration);
// Set the expiration to the actual Unix timestamp of the end of the
// required interval. Also add a tag to it to be able to clear caches more
// precise.
$this->cacheBackend->set('cache_example_expiring_item', $expiration_friendly, $expiration, $tags);
drupal_set_message($this->t('cache_example_expiring_item was set to expire at %time', array('%time' => $expiration_friendly)));

And, also shown in the examples is invalidating:

$tags = array(

So in your preprocess, you could use this type of logic to invalidate the cache. Hope this helps.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.