panopoly_magic-8.x-2.x-dev/tests/modules/panopoly_magic_preview_test/panopoly_magic_preview_test.module

<?php

/**
 * @file
 * Hooks for panopoly_magic_preview_test.
 */

use Drupal\Core\Block\BlockPluginInterface;

/**
 * Implements hook_block_alter().
 */
function panopoly_magic_preview_test_block_alter(&$definitions) {
  /** @var \Drupal\Core\Extension\ExtensionList $module_list */
  $module_list = \Drupal::service('extension.list.module');

  if (!empty($definitions['panopoly_magic_preview_test_altered_settings'])) {
    $definitions['panopoly_magic_preview_test_altered_settings']['preview_settings'] = [
      'message' => 'The altered message',
    ];
  }

  if (!empty($definitions['panopoly_magic_preview_test_altered_image'])) {
    $definitions['panopoly_magic_preview_test_altered_image']['preview_image'] = $module_list->getPath('panopoly_magic_preview_test') . '/images/block-preview.png';
    $definitions['panopoly_magic_preview_test_altered_image']['preview_alt'] = t("panopoly_magic_preview_test: altered preview image");
  }

  if (!empty($definitions['panopoly_magic_preview_test_altered_preview'])) {
    $definitions['panopoly_magic_preview_test_altered_preview']['preview_callback'] = '_panopoly_magic_preview_test_preview_callback';
  }

  if (!empty($definitions['inline_block:panopoly_magic_preview_test'])) {
    $definitions['inline_block:panopoly_magic_preview_test']['category'] = t('Panopoly Magic Preview Test');
    $definitions['inline_block:panopoly_magic_preview_test']['preview_settings'] = [
      'body' => "panopoly_magic_preview_test: content entity preview field value",
    ];
  }
}

/**
 * Block preview callback.
 *
 * @param \Drupal\Core\Block\BlockPluginInterface $block_plugin
 *   The block plugin.
 *
 * @return array
 *   The render array.
 */
function _panopoly_magic_preview_test_preview_callback(BlockPluginInterface $block_plugin) {
  return [
    '#markup' => t("panopoly_magic_preview_test: block preview from a callback"),
  ];
}