@Service
public class CalendarSubscriptionChannelRegistryextends Object
The subscription channels installed on this platform, and the questions
the host asks of them: whose calendar a listed collection is, which uid a
principal addresses, and through which channel an account's subscriptions
are edited.
The contributions are read on each question, through the bean factory, so
a channel from another web application is found whatever the boot order.
channels - the contributions, from every web application, each read on its
own so that one which cannot be created is left out
(ContributedBeans); null reads as none
The channel asked where only a uid, not a principal, is in hand: the
first installed one, the null channel when none is.
Two questions are asked that way: the subscription a share follows at
once, addressed by the uid the share channel read, and the owner listing
the owner cache keeps per server and user, not per channel. Both hold
while one product contributes subscriptions, which is the case this
seam was drawn for; a second one would carry the channel on those two
keys.
The owner listing of an account, as the primary() channel answers
it. The caller only asks for an account whose principal a channel
already named (userUidOf(java.lang.String)).