Resize column select as column width

saulosag

I'm trying to implement a filter for specific columns. The every() of said columns is being delegated to the function below, but width is always turning out to be undefined. What am I doing wrong? Can somenone suggest another way to resize the select as the same width as the column?:

function filtroColuna () {
            var column = this;
            var width = column.width;
            console.log(width);
            var select = $('<select style="max-width:'+width+'px"><option value="">'+this.header().innerHTML+'</option></select>')
            .appendTo( $(column.header()).empty() )
            .on( 'change', function () {
                var val = $.fn.dataTable.util.escapeRegex(
                    $(this).val()
                );
 
                column
                    .search( val ? '^'+val+'$' : '', true, false )
                    .draw();
            });
            column.data().unique().sort().each( function ( d, j ) {
                select.append('<option value="' + d + '">' + d + '</option>')});
        }