progressive_image_loading-8.x-1.x-dev/src/Plugin/Field/FieldFormatter/BackgroundResponsiveImageFormatter.php

<?php

namespace Drupal\progressive_image_loading\Plugin\Field\FieldFormatter;

use Drupal\breakpoint\BreakpointManagerInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\responsive_image\Plugin\Field\FieldFormatter\ResponsiveImageFormatter;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Implementation of the 'Background Responsive Image' formatter.
 *
 * @FieldFormatter(
 *   id = "progressive_image_loading_background_responsive_image",
 *   label = @Translation("Background Responsive Image (Progressive Image Loading)"),
 *   field_types = {
 *     "image"
 *   },
 *   quickedit = {
 *     "editor" = "image"
 *   }
 * )
 */
class BackgroundResponsiveImageFormatter extends ResponsiveImageFormatter {

  use BackgroundImageFormatterBaseTrait;

  /**
   * The breakpoint manager.
   *
   * @var \Drupal\breakpoint\BreakpointManagerInterface
   */
  protected $breakpointManager;

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    $instance = parent::create($container, $configuration, $plugin_id, $plugin_definition);

    $instance->setProgressiveImageLoadingManager($container->get('progressive_image_loading.manager'));
    $instance->setBreakpointManager($container->get('breakpoint.manager'));

    return $instance;
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode) {
    $elements = parent::viewElements($items, $langcode);

    foreach ($elements as $delta => $element) {
      foreach ($this->itemClasses as $class) {
        $elements[$delta]['#item_attributes']['class'][] = $class;
      }

      // Build tye background data attributes by breakpoint, we only support
      // 1x multiplier and image style as image mapping type. Otherwise we can't
      // build the element attributes as our lazy loader expects.
      // We need a breakpoint based list: data-background-image-BREAKPOINT.
      $responsive_image_style = $this->responsiveImageStyleStorage->load($elements[$delta]['#responsive_image_style_id']);
      if ($responsive_image_style) {
        $breakpoint_group = $responsive_image_style->getBreakpointGroup();
        $breakpoints = array_reverse($this->breakpointManager->getBreakpointsByGroup($breakpoint_group));

        foreach ($responsive_image_style->getKeyedImageStyleMappings() as $breakpoint_id => $multipliers) {
          if (!empty($breakpoints[$breakpoint_id]) && !empty($multipliers['1x']) && $multipliers['1x']['image_mapping_type'] == 'image_style') {
            $breakpoint_name = preg_replace('/^' . $breakpoint_group . '\./', '', $multipliers['1x']['breakpoint_id']);
            /** @var \Drupal\Core\Template\Attribute $source */
            $source = _responsive_image_build_source_attributes(['uri' => $elements[$delta]['#item']->entity->getFileUri()], $breakpoints[$breakpoint_id], ['1x' => $multipliers['1x']]);
            [$url] = explode(' ', $source->storage()['srcset']->value());
            $elements[$delta]['#item_attributes']['data-background-image-' . $breakpoint_name] = $url;
            if ($multipliers['1x']['image_mapping'] == $responsive_image_style->getFallbackImageStyle()) {
              $elements[$delta]['#item_attributes']['data-background-image'] = $url;
              $style = 'background-image: url(' . $this->progressiveImageLoadingManager->createPlaceholder($url) . ');';
              $elements[$delta]['#item_attributes']['style'] = empty($elements[$delta]['#item_attributes']['style']) ? $style : $style . ' ' . $elements[$delta]['#item_attributes']['style'];
            }
          }
        }
      }
    }

    return $elements;
  }

  /**
   * Sets the breakpoint manager.
   *
   * @param \Drupal\breakpoint\BreakpointManagerInterface $breakpoint_manager
   *   The breakpoint manager.
   *
   * @return $this
   */
  protected function setBreakpointManager(BreakpointManagerInterface $breakpoint_manager) {
    $this->breakpointManager = $breakpoint_manager;

    return $this;
  }

}