Code snippet that can be used to add a class to the body tag in Drupal 8.
/**
* @param $variables
*/
function mymodule_preprocess_html(&$variables)
{
$node = \Drupal::routeMatch()->getParameter('node');
if ($node) {
$variables['attributes']['class'][] = 'page-' . $node->id();
}
}
Example how to add a class to the body tag in specific node:
/**
* @param $variables
*/
function THEMENAME_preprocess_html(&$variables)
{
$node = \Drupal::routeMatch()->getParameter('node');
if ($node instanceof \Drupal\node\NodeInterface) {
if ($node->id() == 1 || $node->getType() == "article") {
$variables['attributes']['class'][] = 'article-page-1';
}
}
}