discourse/app/serializers/user_serializer.rb

class UserSerializer < BasicUserSerializer
  
  attributes :name, 
             :email, 
             :last_posted_at, 
             :last_seen_at, 
             :bio_raw,
             :bio_cooked, 
             :created_at, 
             :website, 
             :can_edit, 
             :stream, 
             :stats, 
             :can_send_private_message_to_user,
             :bio_excerpt,
             :invited_by,
             :trust_level


  def self.private_attributes(*attrs)
    attributes *attrs
    attrs.each do |attr|
      define_method "include_#{attr}?" do 
        can_edit
      end
    end
  end

  def bio_excerpt
    e = object.bio_excerpt
    unless e && e.length > 0 
      e = if scope.user && scope.user.id == object.id
        I18n.t('user_profile.no_info_me', username_lower: object.username_lower)
      else
        I18n.t('user_profile.no_info_other', name: object.name)
      end
    end
    e
  end

  private_attributes :email, 
             :email_digests, 
             :email_private_messages, 
             :email_direct,
             :digest_after_days,
             :auto_track_topics_after_msecs

  def auto_track_topics_after_msecs
    object.auto_track_topics_after_msecs || SiteSetting.auto_track_topics_after
  end

  def can_send_private_message_to_user
    scope.can_send_private_message?(object)
  end

  def stats
    UserAction.stats(object.id, scope)
  end

  def stream
    UserAction.stream(user_id: object.id, offset: 0, limit: 60, guardian: scope)
  end

  def can_edit
    scope.can_edit?(object)
  end

end