# File app/models/certif_format_line.rb, line 20
  def text_for(person,conference)
    case content_source
    when 0
      return content
    when 1
      obj = person 
    when 2
      obj = conference
    else
      raise NoMethodError, _('Undefined content source %d for %d (%d)') % 
        [content_source, id, certif_format_id]
    end

    return obj.send(content) if
      obj.class.column_names.include? content
    raise NoMethodError, _('Undefined attribute %s for %s in format ' <<
                           'line %d (%d)') % [content, obj.class, 
                                              id, certif_format_id]
  end