Schedule cron jobs using Ultimate Cron

Question

In one of my modules I would like to create two different cron jobs to handle two different procedures. What I did was to use the Ultimate Cron module, and by implementing the cron api, to schedule one of my cron jobs.

My problem is that in /admin/config/system/cron/jobs only the default from the hook_cron appears and not from the hook_cronapi. This is what I wrote.

/**
 * Implements hook_cron().
 */
function MODULENAME_cron() {
  //code
}

/**
 * Implements hook_cronapi().
 */
function MODULENAME_cronapi() {
  $items = array();

  $items['generate_excel_files'] = array(
    'title' => 'Table Excel Generate',
    'callback' => 'generate_excel_files_callback',
    'scheduler' => array(
      'name' => 'crontab',
      'crontab' => array(
        'rules' => array('0 3 * * *'),
      ),
    ),
  );

  return $items;
}

function generate_excel_files_callback(){
  //code
}

Answer 1

Apparently cron api dosn't work with Drupal 8 at this time. What I did to fix my issue was to create one new module to handle only the cron job that I wanted. Then from the UI of Ultimate Cron I would add the rule to schedule my cron job.

use Drupal\MODULENAME\Controller\ClassName;

/**
 * Implements hook_cron().
 */
function NEW_MODULENAME_cron() {
 generate_excel_files_callback();
}

function generate_excel_files_callback(){
 $obj = new ClassName();
 $obj->generateXLSX();
}

Answer 2

In reply to "but the cron is not running on the scheduled time." From what I understand, the cron will still only run if a request is sent. So any request to any page. If no request are received from the server, the cron will never run, regardless of the time you set. If a request is received, it will check the time lapsed since the last time cron ran and compare with your set value to decide if it needs running again.