attribute of directive and ng-grid element direct reference

1) attribute of directive 
  - principle : attributes easily modified

<ng-excel excel-data="myData" rows="100" cols="100" width="800" height="200"></ng-excel>

width="800" =>
	template: "<div ng-grid=\"gridOptions\" ng-style=\"myprop()\"></div>",
	ng-style <- 
                   scope.myprop = function() {
				            return {
				                width: attr["width"] + 'px',
				                height: attr["height"] + 'px'

2) ng-grid element direct reference
  - principle : element for rigid trait according to predefined ng-excel type (etc. for mobile, for desktop)

$scope.gridOptions = {
	data: 'ngExcelData',
	columnDefs: 'columnDefs',

'columnDefs' =>

	$scope.columnDefs = [
	    {field:'CHK', displayName:'chk', width: 50 , 
	        cellTemplate:checkboxCellTemplate,
	        sortable:false, pinned:false, enableCellEdit: false },
	    {field:'name', displayName:'name', width: 100, enableCellEdit: true},
	    {field:'contact', displayName:'contact', width: 300, enableCellEdit: true}
	    ];