change: function(evt, ui){ if( ui.source == 'clear' ){ //cells cleared by delete key. }}
var changes = grid.getChanges({ format: 'byVal' }), updateList = changes.updateList;updateList.forEach( function ( rd ){ for(var key in updateList ){ if ( rd[ key ] === undefined ){ //cells cleared } }})
beforeValidate: function(evt, ui){ if(ui.source=='clear'){ return false; } },