Groups implementation

[yvolk]

@yvolk

@ngerakines For me there is a huge difference between “Following” and “Joining”. And unfortunately, for me it looks like you chose the wrong word to describe Joining/Leaving a group

Following an Actor means an intent to receive all activities by that Actor (Group being a type of Actor as per Activity vocabulary https://www.w3.org/TR/activitystreams-vocabulary/#actor-types )

Joining a Group means an intent to receive all activities sent to that Group (not by that group). Actors - members of the group may post a lot more than will be sent to the Group. So you will not receive all activities by the Group members.

And thinking further I see that both “Follow a Group” and “Join a Group” activities really make sense in terms of ActivityPub, but they have different meaning:

• Join a Group - an intent to receive all activities sent to that Group by members of the Group.
• Follow a Group - an intent to receive all activities sent by the Group i.e. by the Group as an Actor. This is similar to following a Server’s admin.

@tcit

@nightpool

When Activities are received in the inbox, the server needs to forward these to recipients that the origin was unable to deliver them to. To do this, the server MUST target and deliver to the values of to , cc , and/or audience if and only if

Could you explain your understanding of these words in details for this concrete case:
A “Create” Activity having a Group in its “to” property arrived to a Server, which hosts (owns) this Group. The Actor of this activity is a member of this group. The group has 500 members, some of them are from the same server, some from 4 others (to be concrete).
What should the Server (System) do?