Facebook Messenger — [Notes]
simple messenger system feature
May 10, 2022
with a number suffix corresponding to the visual on the figure.
- A user has a list of contacts
- from which she can see who is online/offline
- The user can pick any one or multiple of her contacts and start a chat
- In a chat, all participants can send messages
- The messages will be displayed in chronological order.
- A message can be “liked” by any participant, whose avatar is then attached to the “liked” message.
- A participant’s avatar is also displayed after the last message she read, signalling her progress to other participants.
- A participant can delete any message in her own chat view.
- Only the sender of a message can delete it for all participants.
- Any user can leave a chat.
Data objects
