json.author do
  json.partial! "users/user_simple", user: message.user
end

json.id message.id
json.content message.contents_show(identity)
json.time time_from_now(message.created_at)
json.hidden message.hidden
# 主贴与子贴不一致
if message.m_parent_id
  json.can_delete message.can_delete(identity)
else
  json.praise_count message.praise_treads.select{|pt| pt.praise_or_tread == 1}.count
  json.user_praise message.praise_treads.select{|pt| pt.praise_or_tread == 1 && pt.user_id == current_user.id}.count
  json.child_message_count message.m_reply_count
end
