mailjet-8.x-2.7/modules/mailjet_commerce/mailjet_commerce.install

<?php

/**
 * @file
 * Install, update and uninstall functions for the Commerce module.
 */

/**
 * Implements hook_requirements().
 */
function mailjet_commerce_requirements($phase) {
  $requirements = [];
  $config_mailjet = \Drupal::config('mailjet.settings');

  if ($phase === 'install') {
    if (empty($config_mailjet->get('mailjet_active'))
      || empty($config_mailjet->get('mailjet_username'))
      || empty($config_mailjet->get('mailjet_password'))) {
      $requirements['mailjet_commerce'] = [
        'severity' => REQUIREMENT_ERROR,
        'description' => t('Mailjet Commerce module requires the Mailjet module to be configured. Please enable Mailjet module and enter Mailjet API keys.'),
      ];
    }
  }
  return $requirements;
}

/**
 * Implements hook_uninstall().
 */
function mailjet_commerce_uninstall() {
  /* @var $entityFieldManager Drupal\Core\Entity\EntityFieldManager */
  $entityFieldManager = \Drupal::service('entity_field.manager');

  $fields = $entityFieldManager->getFieldDefinitions('commerce_order', 'default');

  if (isset($fields['field_mailjet_campaign_name'])) {
    $fields['field_mailjet_campaign_name']->delete();
  }

  if (isset($fields['field_mailjet_campaign_id'])) {
    $fields['field_mailjet_campaign_id']->delete();
  }

}