field_css-2.0.0-rc4/field_css.module

<?php

/**
 * @file
 * Primary module hooks for Field CSS module.
 */

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Session\AccountInterface;
use Drupal\field_css\Traits\CssTrait;

/**
 * Implements hook_entity_view_alter().
 */
function field_css_entity_view_alter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {
  $prefixes = (
    new class() {
      use CssTrait;

    }
  )->itemPrefixes($entity, $display->getMode());

  if ($prefixes) {
    foreach ($prefixes as $prefix) {
      $build['#attributes']['class'][] = $prefix;
      // Layout Builder strips attributes before rendering entities as
      // components. As a workaround, the classes are added to a custom
      // #field_css array, which can be passed through to Layout Builder.
      // Using a #field_css guarantees only classes added here are added back
      // in \Drupal\field_css\EventSubscriber\BlockComponentRenderArray.
      $build['#field_css']['class'][] = $prefix;
    }
  }
}

/**
 * Implements hook_entity_field_access().
 */
function field_css_entity_field_access($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, FieldItemListInterface $items = NULL) {
  if ($operation == 'edit' && $field_definition->getType() == 'css') {
    return AccessResult::forbiddenIf(!$account->hasPermission('access css fields'))
      ->addCacheContexts(['user.permissions']);
  }
  return AccessResult::neutral();
}

/**
 * Implements hook_codemirror_editor_assets_alter().
 */
function css_field_codemirror_editor_assets_alter(array &$assets) {
  // Ensure CodeMirror provides CSS mode.
  $assets['js'][] = 'mode/css/css.min.js';
}