When Omeka detects that a user has installed a new version of the plugin, it automatically deactivates the plugin and presents an “Upgrade” button. This hook runs when a superuser clicks the “Upgrade” button. It is primarily used to migrate database tables and other data stored by older versions of the plugin.

To abort the upgrade and report an error to the user, throw an Omeka_Plugin_Installer_Exception.


string old_version
The previous version that was installed and is being upgraded from.
string new_version
The new, current version of the plugin.