modifiers.module

<?php

/**
 * @file
 * Modifiers module.
 */

use Drupal\Component\Utility\Html;
use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\FieldableEntityInterface;
use Drupal\Core\Render\Element;
use Drupal\modifiers\Modifiers;

/**
 * Implements hook_preprocess_HOOK().
 */
function modifiers_preprocess_html(&$variables) {

  // Attach initialization script for all JS modifications.
  $variables['#attached']['library'][] = 'modifiers/init';
}

/**
 * Implements hook_entity_view_alter().
 */
function modifiers_entity_view_alter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {

  if (!($entity instanceof FieldableEntityInterface) || !$entity->hasField(Modifiers::FIELD)) {
    return;
  }

  $entity_type = $entity->getEntityTypeId();
  $entity_id = Html::getClass($entity_type . '-' . $entity->id());
  $display_mode = $display->getMode();

  // Skip preview display mode on paragraph entities.
  if ($entity_type === 'paragraph' && $display_mode === 'preview') {
    return;
  }

  // Add common class for all content entities.
  $build['#attributes']['class'][] = 'modifiers';
  // Create an unique entity ID class.
  $build['#attributes']['class'][] = Html::getClass('modifiers-id-' . $entity_id);
  // Add entity type class.
  $build['#attributes']['class'][] = Html::getClass('modifiers-type-' . $entity_type);
  // Add entity bundle class.
  $build['#attributes']['class'][] = Html::getClass('modifiers-bundle-' . $entity->bundle());
  // Add entity display mode class.
  $build['#attributes']['class'][] = Html::getClass('modifiers-display-' . $display_mode);

  // Initialize modifiers service.
  /** @var \Drupal\modifiers\Modifiers $modifiers */
  $modifiers = \Drupal::service('modifiers');

  $config = $modifiers->extractEntityConfig($entity, Modifiers::FIELD, ['modifiers' => []]);

  // Allow other modules to alter extracted config.
  $context = [
    'build' => $build,
    'entity' => $entity,
    'display' => $display,
  ];
  \Drupal::moduleHandler()
    ->alter('modifiers_entity_view_config', $config['modifiers'], $context);

  if (empty($config['modifiers'])) {
    return;
  }

  $build['#modifiers'][] = $config['modifiers'];

  // Selector needs to be very specific.
  $selector = 'html body .modifiers.modifiers-id-' . $entity_id;

  $modifications = [];

  // Fill all modifications.
  $modifiers->process($modifications, $config['modifiers'], $selector);

  if (!empty($modifications)) {
    $modifiers->apply($modifications, $build, $entity_id);
  }
}

/**
 * Implements template_preprocess_layout().
 */
function modifiers_preprocess_layout(&$variables) {
  $blocks = [];

  // Find all modifier blocks between regions.
  foreach (Element::children($variables['content']) as $region_key) {
    $block_keys = Element::children($variables['content'][$region_key]);

    // Search between all blocks inside specific region.
    foreach ($block_keys as $block_key) {
      $region_block = $variables['content'][$region_key][$block_key];

      // Only if block contains a custom block entity.
      if (isset($region_block['content']['#block_content'])) {
        /** @var \Drupal\block_content\Entity\BlockContent $entity */
        $entity = $region_block['content']['#block_content'];

        // Check if this block is of a modifier block type.
        if (substr($entity->bundle(), -9) === '_modifier') {
          // Apply to section if checkbox is checked.
          if ($entity->hasField('field_lb_modifiers_section')
            && !empty($entity->get('field_lb_modifiers_section')->value)
          ) {
            $blocks['section'][] = $entity;
          }
          else {
            // Apply this modifier to region.
            $blocks['region'][$region_key][] = $entity;
          }
        }
      }
    }
  }

  // Process all modifiers if found.
  if (!empty($blocks)) {
    // Get unique ID for every section with modifiers.
    $section_id = &drupal_static(__FUNCTION__, 0);
    $section_id++;

    // Process all section modifiers if available.
    if (!empty($blocks['section'])) {
      $entity_id = 'section-' . $section_id;
      _modifiers_layout_apply($variables, $blocks['section'], $entity_id);
    }

    // Process all region modifiers if available.
    if (!empty($blocks['region'])) {
      foreach ($blocks['region'] as $region_key => $entities) {
        $entity_id = 'section-' . $section_id . '-region-' . $region_key;
        _modifiers_layout_apply($variables, $entities, $entity_id, $region_key);
      }
    }
  }
}

/**
 * Apply modifications extracted from Layout Builder blocks.
 *
 * @param array $build
 *   The build array for rendering.
 * @param array|\Drupal\block_content\Entity\BlockContent[] $entities
 *   The set of modifier blocks.
 * @param string $entity_id
 *   The block entity ID.
 * @param string|null $region
 *   The region name or NULL for section.
 */
function _modifiers_layout_apply(array &$build, $entities, $entity_id, $region = NULL) {

  // Initialize modifiers service.
  /** @var \Drupal\modifiers\Modifiers $modifiers */
  $modifiers = \Drupal::service('modifiers');

  // Compose selector and config to field mapping.
  $selector = 'html body .modifiers.modifiers-id-' . $entity_id;
  $config = [];

  // Process all entities.
  foreach ($entities as $entity) {
    $entity_config = [];

    // Process all fields attached to entity.
    foreach ($entity->getFields() as $field) {
      $modifiers->extractFieldConfig($field, $entity_config);
    }
    // Fill entity values into config array.
    $config[$entity->bundle()][] = $entity_config;
  }

  $modifications = [];
  // Fill all modifications.
  $modifiers->process($modifications, $config, $selector);

  // Apply modifications if available.
  if (!empty($modifications)) {
    if (!empty($region)) {
      $build['region_attributes'][$region]->addClass([
        'modifiers',
        Html::getClass('modifiers-id-' . $entity_id),
      ]);
    }
    else {
      $build['attributes']['class'][] = 'modifiers';
      $build['attributes']['class'][] = Html::getClass('modifiers-id-' . $entity_id);
    }
    $modifiers->apply($modifications, $build, $entity_id);
  }
}