Export Multiple TreeLists to Excel

<script src="//cdnjs.cloudflare.com/ajax/libs/jszip/2.4.0/jszip.min.js"></script>

<button class="k-button k-button-md k-rounded-md k-button-solid k-button-solid-base" id="export">Export TreeLists to Excel</button>

<h3>Designers</h3>
@(Html.Kendo().TreeList<Telerik.Examples.Mvc.Areas.TreeListExportingMultiple.Models.EmployeeDirectoryModel>()
    .Name("designers")
    .Events(e => e.ExcelExport("onExcelExportDesigners"))
    ... // Additional configuration.
)
<h3>Lead personnel</h3>
@(Html.Kendo().TreeList<Telerik.Examples.Mvc.Areas.TreeListExportingMultiple.Models.EmployeeDirectoryModel>()
    .Name("leads")
    .Events(e => e.ExcelExport("onExcelExportLead"))
    ... // Additional configuration.
)

<script>
    function onExcelExportDesigners(e) {
        e.preventDefault();
        promises[0].resolve(e.workbook);
    }

    function onExcelExportLead(e) {
        e.preventDefault();
        promises[1].resolve(e.workbook);
    }

    // Used to sync the exports.
    var promises = [
        $.Deferred(),
        $.Deferred()
    ];

    $(document).ready(function(){
        $("#export").click(function (e) {
            // Trigger the export of the "designers" TreeList.
            $("#designers").data("kendoTreeList").saveAsExcel();
            // Trigger the export of the "leads" TreeList.
            $("#leads").data("kendoTreeList").saveAsExcel();
            // Wait for both exports to finish.
            $.when.apply(null, promises)
                .then(function (designersWorkbook, leadsWorkbook) {

                    // Create a new workbook using the sheets of the "designers" and "leads" workbooks.
                    var sheets = [
                        designersWorkbook.sheets[0],
                        leadsWorkbook.sheets[0]
                    ];

                    sheets[0].title = "Designers";
                    sheets[1].title = "Leads";

                    var workbook = new kendo.ooxml.Workbook({
                        sheets: sheets
                    });

                    promises = [
                        $.Deferred(),
                        $.Deferred()
                    ];

                    // Save the new workbook.
                    kendo.saveAs({
                        dataURI: workbook.toDataURL(),
                        fileName: "DesignersAndLeaders.xlsx"
                    });
                });
        });
    });
</script>