Utilize scan-classes mixin

[jensschuppe]

Follow-up to #520 (comment)

This converts global functions into class methods for proper class loading and avoiding declaration errors when using the scan-classes mixin.

There might be changes needed for optional dependencies like action-provider.

[dontub]

I think an own implementation of hook_civicrm_scanClasses is necessary because of classes extending Civi\ActionProvider\Action\AbstractAction which comes from an optional extension dependency and might not be available, resulting in:

Class "Civi\ActionProvider\Action\AbstractAction" not found

[ufundo]

I think an own implementation of hook_civicrm_scanClasses is necessary because of classes extending Civi\ActionProvider\Action\AbstractAction which comes from an optional extension dependency and might not be available, resulting in:

An alternative is to put the classes which have another dependency into a subextension. This can be automatically enabled if and only if the dependencies are available. See civicrm/civicrm-core#34113

[jensschuppe]

An alternative is to put the classes which have another dependency into a subextension. This can be automatically enabled if and only if the dependencies are available. See civicrm/civicrm-core#34113

That's interesting (and apparently available since 6.10.0)! Seems documentation for that is still missing, and it would definitely be worth a blog post or mention in the dev mailing list.

Anyway, that's the approach to be taken here IMO.

[dontub]

apparently available since 6.10.0

Can we already use this feature? 6.10 is the current ESR, though not all CiviCRM admins are fast when it comes to updates...