app.MapGet("/data/OrderItems", async (
DataServiceDbContext dbContext,
int skip = 0, int take = 20,
string sortField = "Id", bool sortAscending = true) =>
var source =
dbContext.OrderItems.AsQueryable()
.OrderBy(sortField + (sortAscending ? " ascending" : " descending"));
var items = await source.Skip(skip).Take(take).ToListAsync();
var totalCount = await dbContext.OrderItems.CountAsync();
return Results.Ok(new
Items = items,
TotalCount = totalCount
public VirtualServerModeDataLoader(
VirtualServerModeConfigurationInfo configurationInfo)
// For instance, let's assume the backend supports sorting for just one field
if (configurationInfo.SortInfo?.Length > 0)
SortField = configurationInfo.SortInfo[0].SortPropertyName;
SortAscending = !configurationInfo.SortInfo[0].IsDesc;
public string SortField { get; set; } = "Id";
public bool SortAscending { get; set; } = true;
public Task<VirtualServerModeRowsTaskResult>
GetRowsAsync(VirtualServerModeRowsEventArgs e)
return Task.Run(async () =>
using var client = new HttpClient();
var response = await client.GetAsync(
$"{System.Configuration.ConfigurationManager.AppSettings["baseUrl"]}/data/OrderItems?skip={e.CurrentRowCount}&take={BatchSize}&sortField={SortField}&sortAscending={SortAscending}");
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync();
var dataFetchResult =
JsonSerializer.Deserialize<DataFetchResult>(
responseBody, new JsonSerializerOptions
PropertyNameCaseInsensitive = true
if (dataFetchResult is null)
return new VirtualServerModeRowsTaskResult();
var moreRowsAvailable =
e.CurrentRowCount + dataFetchResult.Items.Count < dataFetchResult.TotalCount;
return new VirtualServerModeRowsTaskResult(
dataFetchResult.Items, moreRowsAvailable);
}, e.CancellationToken);
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