menu_icon.php

menu_icon.php

<?php

/**
 * {@inheritdoc}
 *
 * @see hook_preprocess_menu()
 */
function module/theme_preprocess_menu(&$variables) {
	
  if($variables['menu_name'] == '$menu_name' ) {
    foreach ($variables['items'] as $key => &$item) {
			
      $menu_link = $item['original_link'];
      $options = $menu_link->getOptions();
			
      if (isset($options['attributes']['data-icon'])) {
        $variables['items'][$key]['title'] = Markup::create('<i class="'. $options['attributes']['data-icon'] .'"></i><span>' .$item['title'] .'</span>');
      }
    }
  }
}