initialis listen properti chang listen listen object model element regist event modelel chang bodi text action replac add element listen listen model element entri remov object entri action model facad entri model element model facad action entri action oper replac add element listen listen entri action oper object oper model facad oper entri action oper owner replac unlik oper oper chang add element listen listen oper owner object classifi model facad owner oper chang add element listen listen classifi 