Grid Grouping Problem After Update 6.0.2

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Grid

Nolan asked on 31 Jul 2024, 05:26 PM

Hello,

I'm receiving an exception after I upgraded to version 6.0.2. When I try to load a GroupDescriptor on StateInit of a grid, the page crashes. It seems like if the OnRead method is async and takes too long, it causes something to be null and throws a null argument exception. Here's an example for the error:

fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit 'DlYqtxkSjOU4QLgOZWeNdQC1Z5gG3bJP4QfPcowK3-w'.
      System.ArgumentNullException: Value cannot be null. (Parameter 'source')
         at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
         at System.Linq.Enumerable.Select[TSource,TResult](IEnumerable`1 source, Func`2 selector)
         at Telerik.Blazor.Components.TelerikGrid`1.SetProcessedGroups(IEnumerable data)
         at Telerik.Blazor.Components.TelerikGrid`1.SetProcessedData(IEnumerable data)
         at Telerik.Blazor.Components.Common.DataBoundComponent`1.ProcessOnReadResult(ReadEventArgs args)
         at Telerik.Blazor.Components.Common.GridBase`1.<>n__0(ReadEventArgs args)
         at Telerik.Blazor.Components.Common.GridBase`1.ProcessOnReadResult(ReadEventArgs args)
         at Telerik.Blazor.Components.Common.DataBoundComponent`1.ProcessOnReadData()
         at Telerik.Blazor.Components.Common.DataBoundComponent`1.StartDataProcessAsync()
         at Telerik.Blazor.Components.Common.DataBoundComponent`1.ProcessDataOnParametersSetAsync()
         at Telerik.Blazor.Components.Common.DataBoundComponent`1.OnParametersSetAsync()
         at Telerik.Blazor.Components.TelerikGrid`1.OnParametersSetAsync()
         at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
         at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
         at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)

This was working fine when I was using version 5.1.1, but broke when I tried to upgrade to 6.0.2. I added a simplified example to reproduce the error I'm experiencing. I'm running the App in "Server" render mode in case that's relevant.

Test code:

_Host.cshtml

...
<component type="typeof(App)" render-mode="Server" />
...

Test.razor

@page "/"
@using Telerik.DataSource
@using Telerik.DataSource.Extensions;

<div class="k-d-flex-col k-justify-content-center">
    
    <TelerikGrid @ref="GridRef" TItem="Employee" Groupable="true" Pageable="true" Height="400px" OnRead="@ReadAsync" OnStateInit="@StateInit">
        <GridAggregates>
            <GridAggregate Field="Team" Aggregate="@GridAggregateType.Count" />
        </GridAggregates>
        <GridColumns>
            <GridColumn Field=@nameof(Employee.Name) Groupable="false" />
            <GridColumn Field=@nameof(Employee.Team) Title="Team" />
            <GridColumn Field=@nameof(Employee.IsOnLeave) Title="On Vacation" />
        </GridColumns>
    </TelerikGrid>

</div>

@code {
    public TelerikGrid<Employee> GridRef { get; set; }

    public async Task ReadAsync(GridReadEventArgs args)
    {
        var data = new List<Employee>();
        var rand = new Random();
        for (int i = 0; i < 50; i++)
        {
            data.Add(new Employee()
            {
                EmployeeId = i,
                Name = "Employee " + i.ToString(),
                Team = "Team " + i % 5,
                IsOnLeave = i % 2 == 0
            });
            await Task.Delay(50); // simulating DB call
        }

        DataSourceResult result = await data.ToDataSourceResultAsync(args.Request);
        args.Data = result.Data;
        args.Total = result.Total;
        args.AggregateResults = result.AggregateResults;
    }

    public void StateInit(GridStateEventArgs<Employee> args)
    {
        args.GridState.GroupDescriptors = new List<GroupDescriptor>()
        {
            new GroupDescriptor()
            {
                Member = "Team",
                MemberType = typeof(string)
            }
        };
    }

    public class Employee
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
        public bool IsOnLeave { get; set; }
    }
}

Any help would be appreciated.

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