Here is the scenario:

• UI for Blazor version 2.30
• Grid with InCell editing
• EditorTemplate with a DropDownList inside

In version 2.30 there is no longer need for an explicit blur handler for the in-cell editor template. The editor template closes automatically when the user selects a value from the DropDownList. However, the new value is ignored.

REPL test page: https://blazorrepl.telerik.com/mFbcmQvs16Lf1jwv18

Currently, the validation of the grid can be disabled altogether via the GridValidationSettings.Enabled option. However, we cannot control the validation of the grid per column.

Also, we cannot control when the validation is triggered. The simple inputs expose the ValidateOn option, but it cannot be set to the default editors of the grid without the need for an explicit declaration of a custom editor.

Feature Request

Currently, when a grid is rendered with 500 rows in a WASM application and expand/collapse action is initiated, it takes a few seconds to finish grouping and rendering. 

Steps to reproduce

1. Create a grid in WASM app.
2. Add 500 rows.
3. Do not enable paging.
4. Group by any field and initiate expand/collapse.
5. All rows are re-rendered which leads to a few seconds delay.

I would like to lock a column at a certain index in the Grid. For example, I would like to have a column on index 0 (the first column in the Grid) and it should not be reordered by any user interaction (dragging the column itself or dragging other columns in its place). 

Also if the user tries to drag a column over my locked column the drag handlers must not be present/or show that it is an invalid drop location.

===

Telerik edit:

In the meantime, a possible workaround is to:

1. Handle the Grid OnStateChanged event.
2. Check if args.PropertyName is equal to "ColumnStates".
3. Check if the Index of the first Grid column (args.GridState.ColumnStates.First()) is greater than zero.
4. Reset at least 2 column indexes, according to your preferences, so that the first column in the Grid markup is also the first column in the UI.
5. Reset the Grid state with SetStateAsync().

<p>The <strong>Name</strong> column index will always be 0.
    The Grid will either move the reordered column to index 1, or put it back to its previous index (revert).</p>

<p><label><TelerikCheckBox @bind-Value="@ShouldRevertGridColumnOrder" /> Revert Invalid Column Reordering</label></p>

<TelerikGrid @ref="@GridRef"
             Data="@GridData"
             TItem="@SampleModel"
             Pageable="true"
             Sortable="true"
             Reorderable="true"
             OnStateChanged="@OnGridStateChanged">
    <GridColumns>
        <GridColumn Field="@nameof(SampleModel.Name)" Reorderable="false" />
        <GridColumn Field="@nameof(SampleModel.GroupName)" />
        <GridColumn Field="@nameof(SampleModel.Price)" />
        <GridColumn Field="@nameof(SampleModel.Quantity)" />
        <GridColumn Field="@nameof(SampleModel.StartDate)" />
        <GridColumn Field="@nameof(SampleModel.IsActive)" />
    </GridColumns>
</TelerikGrid>

@code {
    private TelerikGrid<SampleModel>? GridRef { get; set; }

    private List<SampleModel> GridData { get; set; } = new();

    private bool ShouldRevertGridColumnOrder { get; set; }

    private IEnumerable<int>? CachedGridColumnIndexes { get; set; }

    private async Task OnGridStateChanged(GridStateEventArgs<SampleModel> args)
    {
        if (args.PropertyName == "ColumnStates")
        {
            if (args.GridState.ColumnStates.First().Index > 0 && GridRef != null)
            {
                if (ShouldRevertGridColumnOrder)
                {
                    await RevertGridColumnOrder();
                }
                else
                {
                    args.GridState.ColumnStates.First(x => x.Index == 0).Index = 1;

                    args.GridState.ColumnStates.First().Index = 0;

                    await GridRef.SetStateAsync(args.GridState);
                }
            }

            CacheGridColumnOrder();
        }
    }

    private void CacheGridColumnOrder()
    {
        var gridColumnState = GridRef?.GetState().ColumnStates;

        if (gridColumnState != null)
        {
            CachedGridColumnIndexes = gridColumnState.Select(x => x.Index);
        }
    }

    private async Task RevertGridColumnOrder()
    {
        var gridState = GridRef?.GetState();

        if (gridState != null && CachedGridColumnIndexes != null)
        {
            for (int i = 0; i < gridState.ColumnStates.Count; i++)
            {
                gridState.ColumnStates.ElementAt(i).Index = CachedGridColumnIndexes.ElementAt(i);
            }

            await GridRef!.SetStateAsync(gridState);
        }
    }

    protected override void OnAfterRender(bool firstRender)
    {
        if (firstRender)
        {
            CacheGridColumnOrder();
        }

        base.OnAfterRender(firstRender);
    }

    protected override void OnInitialized()
    {
        var rnd = new Random();

        for (int i = 1; i <= 7; i++)
        {
            GridData.Add(new SampleModel()
            {
                Id = i,
                Name = $"Name {i}",
                GroupName = $"Group {i % 3 + 1}",
                Price = rnd.Next(1, 100) * 1.23m,
                Quantity = rnd.Next(0, 1000),
                StartDate = DateTime.Now.AddDays(-rnd.Next(60, 1000)),
                IsActive = i % 4 > 0
            });
        }
    }

    public class SampleModel
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public string GroupName { get; set; } = string.Empty;
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public DateTime StartDate { get; set; }
        public bool IsActive { get; set; }
    }
}

Based on some program logic and conditions I want to programmatic scroll to a chosen row so the user can see a specific row. For example:

- Scroll to a selected row

- Scroll to a record, based on its Id

-Scroll to the top of the Grid when the user adds a new item

- Scroll to an expanded item in hierarchical Grid

=====ADMIN EDIT======

We have a knowledge-based article that showcases how to scroll the Grid to the selected row. This article links to a sample GitHub application where you see code samples. If you need to scroll to another row, you can use a similar approach.

I want to filter a Grid by DateTimeOffset? field

===ADMIN EDIT===

There are two possible options:

1. Use a DTO in which you have a DateTime field converted as desired by your app from the DateTimeOffset. Filtering, sorting, editing, and grouping on DateTime values are supported out-of-the-box.

REPL example that demonstrates this approach. 

2. Use the Grid Filter Template. As a filter editor, you can use the DateTimePicker component, which supports the DateTimeOffset type. 

REPL example that demonstrates this approach. 

Hello there,

I am looking for the ability to display hierarchical data in the grid control similar to that available in the asp.net core grid: https://demos.telerik.com/aspnet-core/grid/hierarchy

Thanks!

Currently the blazor grid must be a specific, static height.  If one is not provided, the grid uses a default of 500px.

Kendo grid implementations in other UI frameworks allow for more flexibility in the height of the grid.  It would be great if the blazor implementation could support this as well. 

Two specific scenarios that are valueable:

1) Grid height adjusts to accomodate all of the items in the grid

For other kendo grid implementations, this is typically the case when "Scrollable" is set to false.   If there is a plan to allow toggling scrolling for the blazor grid, then I think that this would come along with that.

2) Ability to set grid height to 100%

With other kendo implementations this is normally done via CSS, and is useful for when you want a "full screen" grid.  This is normally combined with "Scrollable=true" and often combined with Pagination="true" as well.   Currently it's not possible to do this - since the height is defined on the k-grid element, it cannot be overridden with CSS.

Hello,

I want to have the TelerikGrid's "Add" command display a popup for the new record's details, in the same way that the "Edit" functionality does. However with:

        <TelerikGrid EditMode="popup">
            <TelerikGridToolBar>
                <TelerikGridCommandButton Command="Add" Icon="add">Add</TelerikGridCommandButton>

When I click "Add", the new blank row is shown within the grid identical to EditMode="inline", not as a popup. Is the "Add" functionality meant to work in popup mode?

Please allow to set Group By fields at Design time, currently only user has control to Drag and drop to group.

we need feature to group by fixed set of columns and don't allow user to change the grouping, also need option to hide group collapse icons.

I have a simple Grid with custom detail template

    <Telerik.Blazor.Components.TelerikGrid Data="@GridData" FilterMode="Telerik.Blazor.GridFilterMode.FilterRow" >

        <GridColumns>
            <Telerik.Blazor.Components.GridCheckboxColumn Title="Selected"></Telerik.Blazor.Components.GridCheckboxColumn>
            <Telerik.Blazor.Components.GridColumn Title="Name" Filterable="true" Field="@nameof(GridItem.Text)"></Telerik.Blazor.Components.GridColumn>
            <Telerik.Blazor.Components.GridColumn Field="@nameof(GridItem.Date)" Filterable="true" Title="Date"></Telerik.Blazor.Components.GridColumn>
            <Telerik.Blazor.Components.GridColumn Field="@nameof(GridItem.Id)" Filterable="true" Title="Id"></Telerik.Blazor.Components.GridColumn>
            <Telerik.Blazor.Components.GridColumn Field="@nameof(GridItem.ParentIdValue)" Filterable="true" Title="Parent Id"></Telerik.Blazor.Components.GridColumn>
            <Telerik.Blazor.Components.GridColumn Field="@nameof(GridItem.HasChildren)" Filterable="true" Title="Has Children"></Telerik.Blazor.Components.GridColumn>
        </GridColumns>

        <DetailTemplate>
            <div>Custom Template</div>
        </DetailTemplate>

    </Telerik.Blazor.Components.TelerikGrid>

And here is what it looks like. Filters are moved one column to the left. When I remove DetailTemplate everything is ok.

I am using EF on my backend and when I group I get an error like this one:

Unhandled exception rendering component: Processing of the LINQ expression '(GroupByShaperExpression:
      KeySelector: (t.FirstName), 
      ElementSelector:(EntityShaperExpression: 
          EntityType: Customer
          ValueBufferExpression: 
              (ProjectionBindingExpression: EmptyProjectionMember)
          IsNullable: False
      )
      )' by 'RelationalProjectionBindingExpressionVisitor' failed. This may indicate either a bug or a limitation in EF Core. See https://go.microsoft.com/fwlink/?linkid=2101433 for more detailed information.
System.InvalidOperationException: Processing of the LINQ expression '(GroupByShaperExpression:
KeySelector: (t.FirstName), 
ElementSelector:(EntityShaperExpression: 
    EntityType: Customer
    ValueBufferExpression: 
        (ProjectionBindingExpression: EmptyProjectionMember)
    IsNullable: False
)
)' by 'RelationalProjectionBindingExpressionVisitor' failed. This may indicate either a bug or a limitation in EF Core. See https://go.microsoft.com/fwlink/?linkid=2101433 for more detailed information.
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)

and a lot more line through the EF Core expression classes.

-----

ADMIN EDIT

    protected override void OnInitialized()
    {
        GridData = ProductService.GetProducts().ToList();
    }

----

On initialization of the Grid the oDataString is correct, but when I apply a Filter (through the FilterMenu) or apply a sort to a Grid column the ToODataString extension method throws with null reference exception. If the FilterMode is set to FilterRow or revert back to 2.16.0 everything works as expected. 

<AdminEdit>

This bug extends to the functionality of the FilterMenu as a feature and is not connected only to the ToODataString();

</AdminEdit>

It would be really nice now that we have a grid loader, to be able to customize this using a custom template.

Currently it fixes even the animation type, so while we have chosen a different enum (Pulsing) for all our loaders, our grids now look different because it is not possible currently to change the grid loader beyond turning it on and off.

When the Grid has a non-grouped column at first position, there is a missing left border in an adjacent cell on the second line of the header area.

First reported in:

https://www.telerik.com/forums/multi-column-line-in-grid-occasionally-missing

Possible workarounds:

• Move the non-grouped column to another position.
• Wrap the non-grouped column in its own group.

Test page to reproduce:

(Uncomment the group column to use the second workaround from above.)

<TelerikGrid Data="@Data">
    <GridColumns>
        @*<GridColumn Title="Title">
        <Columns>*@
            <GridColumn Field="ID" />
        @*</Columns>
        </GridColumn>*@
        <GridColumn Title="Group">
            <Columns>
                <GridColumn Field="Name" />
            </Columns>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {

    public List<GridItem> Data { get; set; } = new List<GridItem>() {
        new GridItem() { ID = 1, Name = "Name 1" }
    };

    public class GridItem
    {
        public int ID { get; set; }
        public string Name { get; set; }
    }
}