d9-eql/web/themes/custom/eql/eql.theme

<?php
/*
	* @files
	* Theme Template Funtions
*/

// use Drupal\Core\Template\Attribute;
// use Drupal\Core\Link;
// use Drupal\Core\Url;


function eql_preprocess_html(&$variables) {
  $node = \Drupal::routeMatch()->getParameter('node');
  if ($node){
    $variables['attributes']['class'][] = 'node-type-' . $node->bundle();
    $variables['attributes']['class'][] = 'node-id-' . $node->id();
  }
}

function eql_preprocess_node(&$variables){
  $node = &$variables['node'];
  $variables['attributes']['class'][] = 'node-type-' . $node->gettype();
  if($node->gettype() == "actualite") {
    $actu_type = $node->get('field_actu_type')->getString();
    $variables['attributes']['class'][] = 'actu-type-' . $actu_type;
  }
}

///////////////////////////////////////////////////


// counter pour id

            // function eql_preprocess_field(&$variables) {
            //   // static $counter = 0;
            //   // $variables['counter'] = $counter++;
            //   $variables['elements']['#paragraph']->item_id;
            // }
// la fonction suivante ne fonctionne pas
// function eql_preprocess_field(&$variables) {

//   $paragraph = &$variables['paragraph'];
//   $variables['attributes']['class'][] = 'paragraph-type-' . $paragraph->id();
//   $hook_id = $paragraph->get('paragraph-id--')->getString();
//   $variables['attributes']['class'][] = 'hook-id-' . $hook_id;
// }
                  //might be useful for if-clause: $variables['field_name'] and $variables['field_type']
                  // if ($paragraph && $paragraph->getEntityTypeId() == 'paragraph' . $paragraph->id() ) {
                    //whatever logic you need goes here, e.g. something like
                    //$variables['attributes']['data-from-parent-paragraph'] = $parentEntity->getYourStuff();
                  // }



                // function yourtheme_preprocess_field(&$variables, $hook) {
                //   $element = $variables['element'];
                //   $parentEntity = $element['#object'];
                //   //might be useful for if-clause: $variables['field_name'] and $variables['field_type']
                //   if ($parentEntity && $parentEntity->getEntityTypeId() == 'paragraph' ) {
                //     //whatever logic you need goes here, e.g. something like
                //     //$variables['attributes']['data-from-parent-paragraph'] = $parentEntity->getYourStuff();
                //   }
                // }

                // $variables['elements']['#entity']->item_id;

                // function MYTHEME_preprocess_views_view_fields__view_machine_name(&$vars) {
                //   static $counter = 0;
                //   $vars['counter'] = $counter++;
                // }