Action: wu_transition_domain_primary_domain

Fires when the primary domain of a domain transitions from one value to another.

This hook is fired by BerlinDB when a database UPDATE changes the primary_domain column for a domain row.

Parameters

Name	Type	Description
$old_value	`int`	The previous primary domain value.
$new_value	`int`	The new primary domain value.
$item_id	`int`	The domain ID.