themename.theme

<?php

/**
 * @file
 * Functions to support theming in the THEMENAME theme.
 */

 /**
  * Implements hook_preprocess_html().
  */
function themename_preprocess_html(&$variables) {

  // Add a body class based on the route, so scss containers can be added to non-node pages.
  $route_name = \Drupal::request()->attributes->get('_route');
  $variables['attributes']['class'] = 'route--'. \Drupal\Component\Utility\Html::cleanCssIdentifier($route_name, [ '.' => '-', '_' => '-']);
}


/**
 * Implements hook_preprocess_paragraph().
 */
function themename_preprocess_paragraph(&$variables) {

  // If a paragraph has a boolean field to hide the heading, provide a class for css.
  if ($variables['paragraph']->hasField('field_hide_heading') && in_array($variables['paragraph']->get('field_hide_heading')->getString(), ["1", "On"])) {
    $variables['attributes']['class'][] = "paragraph--hidden-heading";
  }

  // If a paragraph has a boolean field to show an alternate style, provide a class for css.
  if ($variables['paragraph']->hasField('field_alternate_style') && in_array($variables['paragraph']->get('field_alternate_style')->getString(), ["1", "On"])) {
    $variables['attributes']['class'][] = "paragraph--alternate-style";
  }
}


/**
 * Implements hook_preprocess_views_view().
 */
function themename_preprocess_views_view(&$variables) {
  // If this view is displaying rendered entities, pass the view mode to the template to add a class.
  if (isset($variables['view']->rowPlugin->options['view_mode'])) {
    $variables['view_mode'] = $variables['view']->rowPlugin->options['view_mode'];
  }
}


/**
 * Implements hook_preprocess_image().
 */
function themename_preprocess_image(&$variables) {

  // Don't print the alt text for an image if it appears to be a filename.
  if (in_array(substr($variables['alt'], strrpos($variables['alt'], '.') + 1), ['jpg', 'jpeg', 'png', 'gif'])) {
    $variables['attributes']['alt'] = '';
    $variables['attributes']['title'] = '';
  }
}


/**
 * Implements template_preprocess_image_formatter().
 */
function themename_preprocess_image_formatter(&$variables) {

  // Output focal point values as an object-position style in the img element to allow css to pseudo-crop it with object-fit: cover.
  if (isset($variables['item']->target_id)) {
    if ($file = \Drupal::service('entity_type.manager')->getStorage('file')->load($variables['item']->target_id)) {
      if ($crop_type = \Drupal::config('focal_point.settings')->get('crop_type')) {
        if ($crop = \Drupal\crop\Entity\Crop::findCrop($file->getFileUri(), $crop_type)) {
          $anchor = \Drupal::service('focal_point.manager')
            ->absoluteToRelative($crop->x->value, $crop->y->value, $variables['item']->width, $variables['item']->height);
          $variables['image']['#attributes']['style'] = "object-position: {$anchor['x']}% {$anchor['y']}%;";
        }
      }
    }
  }
}


/**
 * Implements template_preprocess_responsive_image_formatter().
 */
function themename_preprocess_responsive_image_formatter(&$variables) {

  // We need to use the same code as a regular image formatter, so just call that, and then move the result to the right place.
  themename_preprocess_image_formatter($variables);
  $variables['responsive_image']['#attributes']['style'] = $variables['image']['#attributes']['style'];
  unset($variables['image']);
}