I'm trying manual source operations with grouping and aggregates, but I get: InvalidOperationException: No generic method 'Sum' on type 'System.Linq.Enumerable' is compatible with the supplied type arguments and arguments. No type arguments should be provided if the method is non-generic

I've edited the sample in the docs of manual source operations with grouping and added some aggregates.

Since some feats with the grid are not compatible with others, it is not easy to understand what is feasible and what is not. I know from the docs that virtual scolling is not compatible with many feats, or that group load on demand is not comaptible with aggregates, but I don't found any about aggregates with manual operations.

Please find the attached demo project

I am having problems with grouping in TelerikGrid.

When I drag the column into the header for grouping, I get an error ArgumentNullException: Value cannot be null, apparently,  somewhere in TelerikGrid.SetProcessedGroups.

@page "/test"

<div>
    <TelerikGrid @ref="grid" Data="@GridData" @bind-Page="Page" PageSize="PageSize"
                 Pageable="true" Sortable="true" Groupable="true"
                 FilterMode="Telerik.Blazor.GridFilterMode.FilterMenu" 
                 ShowColumnMenu="true"
                 TotalCount="@TotalRowCount"
                 SelectionMode="GridSelectionMode.Single"
                 OnRead=@ReadData>
        <GridAggregates>
            <GridAggregate Field=@nameof(TestData.Name) Aggregate="@GridAggregateType.Count" />
            <GridAggregate Field=@nameof(TestData.Surname) Aggregate="@GridAggregateType.Count" />
            <GridAggregate Field=@nameof(TestData.Department) Aggregate="@GridAggregateType.Count" />
        </GridAggregates>
        <GridColumns>
            <GridColumn Field="@(nameof(TestData.Name))" FieldType="typeof(string)" Editable="false" Groupable="true" ShowColumnMenu="false" />
            <GridColumn Field="@(nameof(TestData.Surname))" FieldType="typeof(string)" Editable="false" Groupable="true" ShowColumnMenu="false" />
            <GridColumn Field="@(nameof(TestData.Department))" FieldType="typeof(string)" Editable="false" Groupable="true" ShowColumnMenu="false" />
            <GridCommandColumn Width="60px" Lockable="false" ShowColumnMenu="true">
                <GridCommandButton Command="View" Icon="information" ShowInEdit="false" OnClick="@ViewItem"></GridCommandButton>
            </GridCommandColumn>
        </GridColumns>
    </TelerikGrid>
</div>


@code {

    protected TelerikGrid<TestData> grid;
    protected List<TestData> GridData { get; set; }
    public int TotalRowCount { get; set; } = 0;
    public int Page { get; set; } = 1;
    public int PageSize { get; set; } = 10;

    protected async Task ReadData(GridReadEventArgs args)
    {
        await LoadData();
    }

    protected async Task LoadData()
    {
        GridData = await GetSampleData();
        TotalRowCount = 100;
    }

    protected async Task<List<TestData>> GetSampleData()
    {
        List<TestData> results = new List<TestData>();

        results.Add(new TestData { Name = "Name1", Surname = "Surname1", Department = "Department1" });
        results.Add(new TestData { Name = "Name2", Surname = "Surname2", Department = "Department1" });
        results.Add(new TestData { Name = "Name3", Surname = "Surname3", Department = "Department1" });
        results.Add(new TestData { Name = "Name4", Surname = "Surname4", Department = "Department1" });
        results.Add(new TestData { Name = "Name5", Surname = "Surname5", Department = "Department2" });
        results.Add(new TestData { Name = "Name6", Surname = "Surname6", Department = "Department2" });
        results.Add(new TestData { Name = "Name7", Surname = "Surname7", Department = "Department2" });
        results.Add(new TestData { Name = "Name8", Surname = "Surname8", Department = "Department3" });
        results.Add(new TestData { Name = "Name9", Surname = "Surname9", Department = "Department3" });
        results.Add(new TestData { Name = "Name10", Surname = "Surname10", Department = "Department4" });

        await Task.Delay(1000); //simulate loading delay ...

        return results;
    }

    protected void ViewItem(GridCommandEventArgs args)
    {
        //navigate to edit view ...
    }

    public class TestData
    {
        public string Name { get; set; }
        public string Surname { get; set; }
        public string Department { get; set; }
    }
}

I am getting the following error:

This happens in Chrome and Edge, in Webassembly and Server-side blazor.

Am I doing something wrong?

Thanks for the help!

The new functionality to have the in-cell editing validate based on the model doesn't work with fluid validation. We use a custom component that integrates fluid validation with blazor which works fine for all controls including telerik input controls, but the built in validation for the grid editing doesn't seem to work with it.

Also there seems to be a bug with the validation using standard attribute validation. If the row you are working on has an existing record that does not validation properly, the in-cell editing will stop working once you go in to any cell and make a change. The edit mode on that cell will close as if everything updated ok, but after that, you will not be able to click into any cell to edit. While normally the data should already be valid, there can be scenarios where new validation rules are applied and existing records would become retroactively invalid.

Thanks,

Alan

The documentation for the GridToolBar here describes Add, but ExcelExport is also seen in the demos:  https://docs.telerik.com/blazor-ui/components/grid/toolbar#built-in-commands

I imagine there are other built-in commands that are valid in the GridToolBar as well.

Hi,

Is it possible to drag grid row to another page on the same grid? 

thanks,
Irina

It would be nice if it was possible to have a grid and have already in a cell the value of 1 and somebody want's to add 4 to it he doesn't have to calculate but could just type 1+4 and the answer (5) would be saved to the grid.

Problem:

Grid exports columns as 0 width unless Grid column widths are specified in px.  This is a terrible experience for users, and specifying grid width in px is terrible when you have users that can be using phones or 4k screens.  Managing Grid for different screen sizes is already hard enough! 

Solution 1: (Good)

The grid should export a default (64px) width for columns that aren't specified in px. Inexperienced Excel users are lost when columns are collapsed, but can easily resize columns as needed when each one is visible!

Solution 2: (Better)

Calculate a width - like [(rem value)*10]px. Even if it isn't perfect it will go a long way to creating something visually pleasing on initial open in Excel.

Hello, 

After just a sort operation, in the event handler of OnStateChanged event, the FilterDescriptors of GridStateEventArgs.GridState is not empty. 

Steps to reproduce : 

1) Implement Grid with OnStateChanged and OnRead : 

<TelerikGrid 
             OnStateChanged="@((GridStateEventArgs<IGetAgences_Agences_Items> args) => OnStateChangedHandler(args))"
             OnRead=@ReadItems

    async Task OnStateChangedHandler(GridStateEventArgs<IGetAgences_Agences_Items> args)
    {
        var filters = args.GridState.FilterDescriptors; // filters are not empty after just a sort opration
      
    }

    async Task ReadItems(GridReadEventArgs args)
    {

        this.LoadData()

        await InvokeAsync(StateHasChanged);
    }

2) Sort a column 

3) The OnStateChanged event is fire

4) In the OnStateChangedHandler,  the filters are not empty : 

Expected behaviors :

If no filters added, the filters of the GridState must be empty 

Thank's

Thomas

https://demos.telerik.com/blazor-ui/grid/grouping?_ga=2.11039728.515490770.1626709907-330381368.1614276734&_gac=1.160841295.1626814954.Cj0KCQjw6NmHBhD2ARIsAI3hrM21z8_X1eDgy6hwuoo7UHXFZd_lG3Q5ZpE0l_1n2AUV9OdtvO8VBikaAmXyEALw_wcB

Typo:

  <span>Produts for sale: @productsCount &nbsp;</span>
Should be Products

Reordering rows with RowDraggable is great but tricky.

Droping while the red line marker is on the upper line of a row works.

Droping while the red line marker is on the bottom line of a row brings the item to the position over the dopped line.

Thus, it is impossible to bring a line to the last position of a table (although one can bring the last row over it's predecessor as a workaround)

It is impractical to set the grid columns to fixed width. I'll explain with example:

I have grid with 4 columns. The grid should have width 100%.

- Column 1: short text, 10-15 characters. I need this one to auto width to content.

- Column 2: checkbox, also auto-width to header title.

- Column 3: free text that may wrap on multiple lines. I need this column to use all available horizontal space so it will push the 4th column to the very right.

- Column 4: button. auto-width to either header title or button width, whichever is wider.

The auto-width feature is already requested: Autofit column widths on data load (telerik.com) but I don't see a feature request to handle the Column 3 scenario.

I'd like to be able to enable the Column Chooser menu on just the Command Column and then keep all the other column menus as-is (I have a combination of various custom filter controls on them, so I don't watch to switch to the Column Menu)

GridCheckBoxColumn:  The check disappears when focus is on a editable cell.

I would prefer if you can use the FilterMenuTemplate in such a way that you can fetch also "filter criteria" from other fields/columns.

An example:

- grid has 3 coluns > Name, City, Population

- filter mode is set to filter menu and my filter menu should display at the first column.

- after the filter dialog is opened my expactation is that it includes also entries from other fields

In summary, my team would welcome the opportunity of central approach for filtering with multiple fields.

Regards,

Özmen

Documentation states that Grid supports Virtualization with Grouping if it is done by loading the Groups on-demand.

See:

On page: Blazor Grid - Load Group Data On Demand | Telerik UI for Blazor

From this, it appears that Virtual Scrolling, Group Load on Demand, and pagination of the results should function as expected.  I'm specifically focusing on the section where it says "load on demand for the data when the user expands a group or when they scroll to need a new set of available groups".

The behavior I am seeing in my Telerik Repl is not matching up with that.

See:  https://blazorrepl.telerik.com/QFbmurvT41eZq6Ld34

In the repl, I have added some Console.WriteLines to see when OnRead is actually called, as well as to log out some other information about the OnRead Request.  It can be seen that no pagination information is included in the request (PageSize = 0, Skip = 0) while the PageSize is set on the actual Grid component (PageSize = 20).

As a result, all groups are loaded initially, which will be problematic if my server-side data set is being grouped on a value that will result in thousands/millions of groups.

It is possible that I missed something in the documentation that would enable the expected behavior (the Grid actually giving me PageSize and Skip so pagination will actually work), but it is also equally possible that this was never intended behavior, and I have been misled by the documentation page.