Add another optional argument to the schedule command that allows the requester to specify a role from the server to indicate which people should be event participants.
Check that everyone with that role is a member of the text channel that the request was made in; if at least one is not, cancel the event and state the error.
Add another optional argument to the schedule command that allows the requester to specify a role from the server to indicate which people should be event participants.
Check that everyone with that role is a member of the text channel that the request was made in; if at least one is not, cancel the event and state the error.