Messages belong to users/rooms vs belonging to participants

[fastjames]

Hello, and thanks for putting together your chat tutorial. As I was following along, I noticed in

turbochat/app/models/message.rb

Line 2 in 3f3f2e7

belongs_to :user

that Message appears to restate the associations in Participant (belongs_to user and room). Is there a reason to prefer this over making a Message belong_to participant? I couldn't think of one but you're the one who wrote the tutorial so I figured you might have some experience that caused you to make that specific choice.

[fastjames]

I think I answered my own question with some more reading; Participant represents the current state of a user who is associated with the room, where a Message is a historical record of something a participant sent to the room in the past. A user could cease participating in a room (i.e. their participant record could be deleted) but we would still want to retain their message history in the room.