Using Drupal Queue

Question

I think I am close to getting a queue to work with the Drupal 7 Queue API. I have some code that returns a value to me that I want to retrieve on cron.

function ...{
  $guid_to_enqueue = $guid;
  //Add GUID into the queue so we can work with it on cron
  $queue = DrupalQueue::get('custom_application_guid_queue');
  $queue->createQueue();
  $queue->createItem($guid_to_enqueue);
}

I then have

function custom_application_cron_queue_info() {
  $queues[ 'custom_application_guid_queue' ] = array(
    'worker callback' => '_custom_application_guid_item',
    'time' => 30,
  );
  watchdog('custom_application_ques_on_cron',  '<pre>' . print_r($queues, TRUE) . '</pre>');
  return $queues;
}

I think the problem is when I try and use the callback. I am not sure how to iterate over my data that is in the queue. I know it is in the queue using Drush and if I use Watchdog() with $guid_to_enqueue I can see the right value in the variable.

function _custom_application_guid_item($queues) {
 foreach($queues as $quid_item) {
   watchdog('custom_application_guid_item_foreach', $quid_item);
 }
}

Any help with figuring out what I am doing wrong here is greatly appreciated. I have also tried getting the number of items in the queue but nothing is getting that far in my code.

I will add that I will rarely have more than two items in the queue if that changes anything.

Thanks, Josh

Answer 1

Your queue worker callback takes a single queue item to process at a time, and you do not invoke it manually because you have setup cron to do it for you.

Drupal cron will try to process as many queue items within the time that you provided in hook_cron_queue_info(), and this should be first in, first out by the time the queue item was added and then by the primary key.

So in your cron queue worker callback you should expect the data that you enqueued.

function _custom_application_guid_item($guid_enqueued) {
  // Do something with $guid_enqueued
}