Create save send
A discussion can be directly associated to a message in case of a reply so the participants will not be editable.
Reply or Compose a message
For a new message (compose button), we let the user choose the recipients and save it as is.
The user can change the recipients with no restrictions.
discussion_id is calculated by the backend each time the draft is saved.
undefined if it is a new draft (compose).
In case of a reply, the
parent_id is set by the client.
And the backend accepts a
participants but it will recalc the
discussion_id and the
participants each time the reply is saved.