#foreach($class in $doc.xWikiClasses)
#set( $nb = $doc.getObjectNumbers("${class.name}"))
<input type="hidden" name="${class.name}_nb" value="$nb" />
#foreach($obj in $doc.getObjects($class.name))
 #if ($obj.xWikiClass)
  #foreach($prop in $class.properties)
   $doc.displayHidden($prop, "${class.name}_${obj.number}_",  $obj)
    #end
  #end
 #end
#end