<?php

declare(strict_types=1);

use Drupal\Core\Template\Attribute;

function _json_forms_add_tooltip_css_class(array &$variables): void {

if ('tooltip' === ($variables['element']['#_json_forms_description_display'] ?? NULL)) {

/** @var \Drupal\Core\Template\Attribute|null $descriptionAttributes */

$descriptionAttributes = $variables['description']['attributes'] ?? NULL;

if (NULL !== $descriptionAttributes) {

// Add the CSS class "json-forms-description-tooltip" to the description

// element. This can be used to process the element with another module.

$descriptionAttributes->merge(new Attribute(['class' => ['json-forms-description-tooltip']]));

}

}

}

function json_forms_preprocess_form_element(array &$variables): void {

_json_forms_add_tooltip_css_class($variables);

}

function json_forms_preprocess_fieldset(array &$variables): void {

_json_forms_add_tooltip_css_class($variables);

}