function cron_example_cron

Implements hook_cron().

We implement hook_cron() to do "background" processing. It gets called every time the Drupal cron runs. We then decide what has to happen in response.

In this example, we log a message after the time given in the state value 'cron_example.next_execution'. Then we update that variable to a time in the future.

Related topics

File

modules/cron_example/cron_example.module, line 29

Code

function cron_example_cron() {
    // We access our configuration.
    $cron_config = \Drupal::config('cron_example.settings');
    // Default to an hourly interval. Of course, cron has to be running at least
    // hourly for this to work.
    $interval = $cron_config->get('interval');
    $interval = !empty($interval) ? $interval : 3600;
    // We usually don't want to act every time cron runs (which could be every
    // minute) so keep a time for the next run in the site state.
    $next_execution = \Drupal::state()->get('cron_example.next_execution', 0);
    $request_time = \Drupal::time()->getRequestTime();
    if ($request_time >= $next_execution) {
        // This is a silly example of a cron job.
        // It just makes it obvious that the job has run without
        // making any changes to your database.
        \Drupal::logger('cron_example')->notice('cron_example ran');
        if (\Drupal::state()->get('cron_example_show_status_message')) {
            \Drupal::messenger()->addMessage(t('cron_example executed at %time', [
                '%time' => date('c'),
            ]));
            \Drupal::state()->set('cron_example_show_status_message', FALSE);
        }
        \Drupal::state()->set('cron_example.next_execution', $request_time + $interval);
    }
}