document queue worker callback

Nice! Thanks!

Committed to 8.x. Thanks again!

Here is patch for D7.

Thanks again, and sorry for the delay -- committed to 7.x.

Ah, well it should be a quick patch to move it? Thanks for noticing...

To clarify:

Inside system.api.php, there is an "@addtogroup callbacks".

The callback defined in this patch, callback_queue_worker(), needs to be moved from its present location in that file to inside the addtogroup callbacks section.

I think there's a couple other things to fix in the original patch also:

- * - 'worker callback': The name of the function to call. It will be called
- * with one argument, the item created via DrupalQueue::createItem().
+ * - 'worker callback': A PHP callable to call that is an implementation of
+ * callback_queue_worker().

"PHP callable" isn't true unless you're running PHP 5.4 or higher - otherwise it must be a standard function, at least for now. See #2342667: Cron and batch processing of queues are not accepting callables

+ * @throws \Exception

The leading slash isn't correct for Drupal 7.

+  $node->save();

That's really not correct for Drupal 7 :) It should be node_save().

How's this?

Silly me :P

- *   - 'worker callback': A PHP callable to call that is an implementation of
- *     callback_queue_worker().
+ *   - 'worker callback': The name of the function to call. It will be called
+ *     with one argument, the item created via DrupalQueue::createItem().

Do we really want to remove the reference to callback_queue_worker()? If we do it seems like it would be a lot harder for people to find it in the documentation.

Here's a new version to move this along. This just uses similar phrasing to what's used for other callbacks in system.api.php.

I actually see a couple more problems here - see the interdiff.

Looks fine to me!

David: do you want me to commit this one? If so assign it to me.

Nah, I can go ahead and take care of it.

Committed to 7.x - thanks!