bootstrap_layout_builder.module

<?php

/**
 * @file
 * Bootstrap Layout Builder module.
 */

use Drupal\Core\Render\Element;
use Drupal\Core\Template\Attribute;
use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function bootstrap_layout_builder_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the bootstrap_layout_builder module.
    case 'help.page.bootstrap_layout_builder':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Add Bootstrap Grid support to Layout Builder module.
      currently, work for both Bootstrap 3 and Bootstrap 4.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_theme().
 */
function bootstrap_layout_builder_theme() {
  return [
    'blb_container_wrapper' => [
      'variables' => [
        'attributes' => [],
        'children' => [],
      ],
    ],
    'blb_container' => [
      'variables' => [
        'attributes' => [],
        'children' => [],
      ],
    ],
    'blb_section' => [
      'template' => 'blb-section',
      'render element' => 'content',
      'base hook' => 'layout',
    ],
  ];
}

/**
 * Implements hook_preprocess_HOOK().
 */
function bootstrap_layout_builder_preprocess_blb_section(&$variables) {
  foreach (Element::children($variables['content']) as $name) {
    if (!isset($variables['content'][$name]['#attributes'])) {
      $variables['content'][$name]['#attributes'] = [];
    }
    $variables['region_attributes'][$name] = new Attribute($variables['content'][$name]['#attributes']);
  }
}