例如,用户输入@John_Smith hi, what's up!?
我想调用 John_Smith 的对象并向他发送通知以让他注意到。
我怎样才能存档呢?
username = @comment ??????(I have no idea how to code it here)
@user = User.find_by_username(username)
current_user.send_message(@user, body, subject)
判断方式是@username(one space)