elasticsearch_helper_preview.module

<?php

use Drupal\Core\Entity\ContentEntityFormInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Entity\ContentEntityInterface;
use Drupal\elasticsearch_helper_content\ElasticsearchContentIndexInterface;

/**
 * Adds "preview" configuration to Elasticsearch indices provided by
 * "elasticsearch_helper_content" module.
 *
 * @param $info
 */
function elasticsearch_helper_preview_elasticsearch_helper_elasticsearch_index_info_alter(&$info) {
  $module_handler = \Drupal::moduleHandler();

  if ($module_handler->moduleExists('elasticsearch_helper_content')) {
    try {
      $entity_type_manager = \Drupal::entityTypeManager();
      $content_index_storage = $entity_type_manager->getStorage('elasticsearch_content_index');

      foreach ($info as &$plugin_definition) {
        if (isset($plugin_definition['content_index_entity_id'])) {
          /** @var \Drupal\elasticsearch_helper_content\ElasticsearchContentIndexInterface $index_entity */
          if ($index_entity = $content_index_storage->load($plugin_definition['content_index_entity_id'])) {
            if ($preview_settings = $index_entity->getThirdPartySetting('elasticsearch_helper_preview', 'preview')) {
              $plugin_definition['preview'] = $preview_settings;
            }
          }
        }
      }
    }
    catch (Exception $e) {
      watchdog_exception('elasticsearch_helper_preview', $e);
    }
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Adds preview settings to Elasticsearch Content Index plugin's form.
 */
function elasticsearch_helper_preview_form_elasticsearch_content_index_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  $form_object = $form_state->getFormObject();
  /** @var \Drupal\elasticsearch_helper_content\ElasticsearchContentIndexInterface $entity */
  $entity = $form_object->getEntity();

  // Get preview settings.
  $preview_settings = $entity->getThirdPartySettings('elasticsearch_helper_preview');

  $form['preview'] = [
    '#type' => 'container',
    '#tree' => TRUE,
    '#weight' => 27,
  ];

  $form['preview']['preview'] = [
    '#type' => 'checkbox',
    '#title' => t('Enable preview'),
    '#description' => t('Check to enable content preview in the front-end application.'),
    '#default_value' => !empty($preview_settings['preview']),
  ];

  // Define available placeholders.
  // @see \Drupal\elasticsearch_helper_preview\PreviewHandler::preparePreviewPath()
  $t_args = [
    '@placeholders' => implode(', ', ['_index', '_id', '_type']),
    '@example' => '{_index}',
  ];

  // @todo Improve UI to allow adding multiple preview contexts. Currently
  // only "default" context is added.
  $form['preview']['default']['path'] = [
    '#type' => 'textfield',
    '#title' => t('Preview path'),
    '#description' => t('Path in the front-end application where preview is rendered. Field names and the following values can be used as placeholders: @placeholders. Example: @example.', $t_args),
    '#default_value' => isset($preview_settings['preview']['default']['path']) ? $preview_settings['preview']['default']['path'] : NULL,
    '#states' => [
      'visible' => [
        ':input[name="preview[preview]"]' => ['checked' => TRUE],
      ],
    ],
  ];

  // Add entity builder.
  $form['#entity_builders'][] = 'elasticsearch_helper_preview_form_elasticsearch_content_index_form_builder';
}

/**
 * Elasticsearch content index plugin form builder.
 *
 * Adds preview settings into Elasticsearch Content Index plugin's third
 * party settings.
 *
 * @param $entity_type
 * @param \Drupal\elasticsearch_helper_content\ElasticsearchContentIndexInterface $entity
 * @param $form
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 */
function elasticsearch_helper_preview_form_elasticsearch_content_index_form_builder($entity_type, ElasticsearchContentIndexInterface $entity, &$form, FormStateInterface $form_state) {
  $preview_settings = $form_state->getValue('preview');

  // Remove preview bool value if preview is enabled.
  if (!empty($preview_settings['preview'])) {
    unset($preview_settings['preview']);

    $entity->setThirdPartySetting('elasticsearch_helper_preview', 'preview', $preview_settings);
  }
  // Remove settings altogether if preview is disabled.
  else {
    $entity->unsetThirdPartySetting('elasticsearch_helper_preview', 'preview');
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function elasticsearch_helper_preview_form_node_form_alter(&$form, FormStateInterface $form_state) {
  $form_object = $form_state->getFormObject();

  if (!($form_object instanceof ContentEntityFormInterface)) {
    return;
  }

  $entity = $form_object->getEntity();
  $op = $form_object->getOperation();

  if ($entity instanceof ContentEntityInterface && in_array($op, ['edit', 'add', 'default'], TRUE)) {
    /** @var \Drupal\elasticsearch_helper_preview\PreviewHandler $preview_handler */
    $preview_handler = \Drupal::service('elasticsearch_helper_preview.preview_handler');

    // Alter the preview button.
    $preview_handler->alterForm($form, $form_state);
  }
}

/**
 * Implements hook_cron().
 */
function elasticsearch_helper_preview_cron() {
  /** @var \Drupal\elasticsearch_helper_preview\PreviewHandler $preview_handler */
  $preview_handler = \Drupal::service('elasticsearch_helper_preview.preview_handler');

  // Remove expired preview indices.
  $preview_handler->garbageCollection();
}