DataGrid - How to export large data on the server

Hi Jens,

To export large amount of data, using the server-side export is the better way to go. The following code sends a POST AJAX request to the "ExportController" API controller:

JavaScript
function isNotEmpty(value) {
    return value !== undefined && value !== null && value !== '';
}
...
const grid = $("#grid").dxDataGrid("instance");
const loadOptions = { ...gridInstance.getDataSource().loadOptions() };
loadOptions.filter = grid.getCombinedFilter();
const gridState = grid.state();
let params = '?';
[
    'sort',
    'filter',
    'totalSummary',
    'group',
    'groupSummary'
].forEach(function (i) {
    if (i in loadOptions && isNotEmpty(loadOptions[i])) { params += `${i}=${JSON.stringify(loadOptions[i])}&`; }
});
params = params.slice(0, -1);
const url = `api/Export${params}`;
$.ajax(url, {
    contentType: "application/json",
    data: JSON.stringify(gridState),
    method: "POST",
    dataType: "json"
});

Define the Export method in this controller as follows:

C#
[Route("api/[controller]")]
[ApiController]
public class ExportController : ControllerBase {
    [HttpPost]
    public object Export(DataSourceLoadOptions loadOptions, [FromBody]object gridState) {
        var dataToExport = (IEnumerable<SampleOrder>)DataSourceLoader.Load(<target DbSet or other context>, loadOptions).data;
        // export data
    }
}

The dataToExport variable contains records that are displayed in the DataGrid taking into account many data-shaping options like filtering, sorting, grouping, and summaries.
The gridState variable contains a JSON object representing the current DataGrid state: Data Grid States. You can parse this information to create the required Report or XLSX file. We don't have ready-to-use code that generates Excel files based on the DataGrid state. You can generate such code by following the general guidance we described in this help topic: Office File API - Get Started.