<a id="exportExcelFatturaIcon" href ="${createLink(action: 'downloadExcel', params: [fileName:excelFileName])}" hidden>click here</a>
<a id="exportCsvFatturaIcon" href ="${createLink(action: 'downloadCSV', params: [fileName:csvFileName])}"  hidden>click here</a>

$("#exportFatturaButton").click(function(){
    var startDate = $("#startDateFattura").val();
    var endDate =  $("#endDateFattura").val();
    $("#loaderModal").modal('show');
    $.ajax({
        url: "${createLink(controller: 'ExportData',action: 'getDataBySearch')}",
        data: {
            startDate: startDate,
            endDate:endDate
        },
        dataType: "html",
        type: "POST",
        success: function (data) {
            $("#loaderModal").modal('hide');
                document.getElementById("exportExcelFatturaIcon").click();
                document.getElementById("exportCsvFatturaIcon").click();
        },
        error: function (xhr, status) {
            $("#loaderModal").modal('hide');
        }, complete: function (xhr, status) {
            $("#loaderModal").modal('hide');
        }
    });
});