@using System.ComponentModel.DataAnnotations 

<TelerikButton ThemeColor="primary" OnClick="@SetGridGroup">Group</TelerikButton>


<TelerikGrid Data=@MyData EditMode="@GridEditMode.Incell" Pageable="true" Height="500px"
            OnUpdate="@UpdateHandler" 
            OnEdit="@EditHandler" 
            OnDelete="@DeleteHandler"
            OnCreate="@CreateHandler" 
            OnCancel="@OnCancelHandler"
            Groupable="true">
    <GridToolBarTemplate>
        <GridCommandButton Command="Add" Icon="@FontIcon.Plus">Add Employee</GridCommandButton>
    </GridToolBarTemplate>
    <GridColumns>
        <GridColumn Field=@nameof(SampleData.ID) Title="ID" Editable="false" />
        <GridColumn Field=@nameof(SampleData.FirstName) Title="Name" />
        <GridColumn Field=@nameof(SampleData.LastName) Title="Last Name" />

        <GridColumn Field=@nameof(SampleData.Team ) Title="Team" />
        <GridCommandColumn>
            <GridCommandButton Command="Delete" Icon="@FontIcon.Trash">Delete</GridCommandButton>
        </GridCommandColumn>
    </GridColumns>
</TelerikGrid>
@code {
    async Task SetGridGroup()
    {
        GridState<SampleData> desiredState = new GridState<SampleData>()
        {
            GroupDescriptors = new List<GroupDescriptor>()
            {
                new GroupDescriptor()
                {
                    Member = "Team",
                    MemberType = typeof(string)
                },
                
            },
            // choose indexes of groups to be collapsed (they are all expanded by default)
            CollapsedGroups = new List<int>() { 0 },
        };
        await Grid.SetStateAsync(desiredState);
    }
    void EditHandler(GridCommandEventArgs args)
    {
        SampleData item = (SampleData)args.Item;
        // prevent opening for edit based on conditionif (item.ID < 3)
        {
            args.IsCancelled = true;// the general approach for cancelling an event
        }
        Console.WriteLine("Edit event is fired.");
    }
    async Task UpdateHandler(GridCommandEventArgs args)
    {
        SampleData item = (SampleData)args.Item;
        await MyService.Update(item);
        await GetGridData();
        Console.WriteLine("Update event is fired.");
    }
    async Task DeleteHandler(GridCommandEventArgs args)
    {
        SampleData item = (SampleData)args.Item;
        await MyService.Delete(item);
        await GetGridData();
        Console.WriteLine("Delete event is fired.");
    }
    async Task CreateHandler(GridCommandEventArgs args)
    {
        SampleData item = (SampleData)args.Item;
        await MyService.Create(item);
        await GetGridData();
        Console.WriteLine("Create event is fired.");
    }
    void OnCancelHandler(GridCommandEventArgs args)
    {
        SampleData item = (SampleData)args.Item;
        Console.WriteLine("Cancel event is fired. Can be useful when people decide to not satisfy validation");
    }
    public class SampleData
    {
        publicint ID { get; set; }
        [Required]
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public string Team {get;set;}
    }
    public List<SampleData> MyData { get; set; }
    async Task GetGridData()
    {
        MyData = await MyService.Read();
    }
    protected override async Task OnInitializedAsync()
    {
        await GetGridData();
    }
   publicstaticclassMyService
    {
        private static List<SampleData> _data { get; set; } = new List<SampleData>();
        public static async Task Create(SampleData itemToInsert)
        {
            itemToInsert.ID = _data.Count + 1;
            _data.Insert(0, itemToInsert);
        }
        publicstaticasync Task<List<SampleData>> Read()
        {
            if (_data.Count < 1)
            {
                for (int i = 1; i < 50; i++)
                {
                    _data.Add(new SampleData()
                    {
                        ID = i,
                        FirstName = "Name " + i.ToString(),
                        LastName = "Last Name " + i.ToString(),

                        Team="Team" +(i%5).ToString()
                    });
                }
            }
            returnawait Task.FromResult(_data);
        }
        public static async Task Update(SampleData itemToUpdate)
        {
            var index = _data.FindIndex(i => i.ID == itemToUpdate.ID);
            if (index != -1)
            {
                _data[index] = itemToUpdate;
            }
        }
        public static async Task Delete(SampleData itemToDelete)
        {
            _data.Remove(itemToDelete);
        }
    }
}