certificate-4.0.0-alpha1/certificate.api.php

<?php

/**
 * @file certificate.api.php
 * Document certificate hooks.
 */

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Session\AccountInterface;

/**
 * Implementation of hook_entity_access().
 *
 * Any module wishing to award a certificate based on arbitrary criteria should
 * implement this hook. The $entity is the entity in question, the $account is
 * the user viewing the entity.
 *
 * Implementations should check that $operation == 'certificate'
 *
 * @return \Drupal\Core\Access\AccessResult
 *   Forbidden if user should not be shown the menu tab or link.
 *   Allowed if user should be able to download a certificate.
 */
function hook_entity_access(EntityInterface $entity, $operation, AccountInterface $user) {
  if ($operation == 'certificate') {
    if (get_score($user) > passing_score($entity)) {
      return \Drupal\Core\Access\AccessResult::allowed();
    }
    else {
      return \Drupal\Core\Access\AccessResult::forbidden();
    }
  }
}

/**
 * Implementation of certificate_template_id_alter().
 *
 * Modify the valid certificates.
 *
 * @param $template_ids
 *   Array of valid certificates.
 *
 * @param \Drupal\Core\Entity\EntityInterface $entity
 *   Entity generating the certificate.
 *
 * @param \Drupal\Core\Session\AccountInterface $account
 *   Account generating the certificate.
 */
function hook_certificate_template_id_alter(&$template_ids, EntityInterface $entity, AccountInterface $account) {
  if ($entity->id() % 2 == 0) {
    // Set certificate to use mycert_1 when the ID is even.
    $template_ids = ['mycert_1'];
  }
}