@page "/t1445600"
@using Telerik.DataSource.Extensions
@using Telerik.DataSource

<h4>Custom filter appled programmatically:</h4>

<ul>
    <li>
        ID &gt; 20 AND (
        <ul>
            <li>Age &lt; 40 OR</li>
            <li>Height &gt; 180</li>
        </ul>
        )
    </li>
</ul>

<TelerikGrid Data="@CurrentGridData"
             TotalCount="@CurrentGridTotal"
             OnRead="GridReadHandler"
             Pageable="true" PageSize="10">
    <GridColumns>
        <GridColumn Field="ID" />
        <GridColumn Field="Name" />
        <GridColumn Field="Age" />
        <GridColumn Field="Height" Title="Height (cm)" />
        @*<GridColumn Field="Weight" Title="Weight (kg)" />*@
    </GridColumns>
</TelerikGrid>

@code {

    public List<Person> RawData { get; set; } = new();
    public List<Person> CurrentGridData { get; set; } = new();
    public int CurrentGridTotal { get; set; }

    private async Task GridReadHandler(GridReadEventArgs args)
    {
        var rootCFD = new CompositeFilterDescriptor();
        rootCFD.LogicalOperator = FilterCompositionLogicalOperator.And;

        var idFD = new FilterDescriptor("ID", FilterOperator.IsGreaterThan, 20);
        rootCFD.FilterDescriptors.Add(idFD);

        var nestedCFD = new CompositeFilterDescriptor();
        nestedCFD.LogicalOperator = FilterCompositionLogicalOperator.Or;

        var ageFD = new FilterDescriptor("Age", FilterOperator.IsLessThan, 40);
        nestedCFD.FilterDescriptors.Add(ageFD);
        var heightFD = new FilterDescriptor("Height", FilterOperator.IsGreaterThan, 180);
        nestedCFD.FilterDescriptors.Add(heightFD);

        rootCFD.FilterDescriptors.Add(idFD);
        rootCFD.FilterDescriptors.Add(nestedCFD);

        args.Request.Filters.Add(rootCFD);

        var result = RawData.ToDataSourceResult(args.Request);
        CurrentGridData = (result.Data as IEnumerable<Person>).ToList();
        CurrentGridTotal = result.Total;
    }

    protected override Task OnInitializedAsync()
    {
        Random rnd = new Random();

        for (int i = 1; i <= 100; i++)
        {
            RawData.Add(new Person()
            {
                ID = i,
                Name = "Name " + i,
                Age = rnd.Next(18, 60),
                Height = rnd.Next(150, 199),
                Weight = rnd.Next(50, 120)
            });
        }

        return base.OnInitializedAsync();
    }

    public class Person
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
        public int Height { get; set; }
        public int Weight { get; set; }
    }
}