Changing the Default Aggregate Function

Environment

Product Version	2018.3.913
Product	RadPivotGrid for WinForms

Description

An example demonstrating how the default aggregate function of a node dragged in the RadPivodFieldList control to the aggregate descriptions area can be changed.

Solution

The data provider used in RadPivotGrid exposes the PrepareDescriptionForField event. The event arguments provide access to the aggregate description and its function.

Not all aggregate functions are suitable for all of the fields and this depends on their type. For example, applying the Average function to a string field this will cause an error.

The example demonstrates how the event can be handled by also performing an additional check for the data type of the field.

Figure 1: Default Aggregate Function

Sample Implementation

• C#
• VB.NET

public partial class RadForm1 : Telerik.WinControls.UI.RadForm
{
    LocalDataSourceProvider provider;

    public RadForm1()
    {
        InitializeComponent();

        this.provider = new LocalDataSourceProvider();
        //Setup the provider and add data
        this.radPivotGrid1.DataProvider = this.provider;
        this.provider.PrepareDescriptionForField += Provider_PrepareDescriptionForField;
    }

    private void Provider_PrepareDescriptionForField(object sender, PrepareDescriptionForFieldEventArgs e)
    {
        PropertyAggregateDescription aggregate = e.Description as PropertyAggregateDescription;
        if (aggregate != null && IsNumericType(e.FieldInfo.DataType) && e.FieldInfo.Name == "Product")
        {
            aggregate.AggregateFunction = AggregateFunctions.Average;
        }
    }

    public static bool IsNumericType(Type type)
    {
        return type == typeof(double)
           || type == typeof(Nullable<double>)
           || type == typeof(int)
           || type == typeof(Nullable<int>)
           || type == typeof(byte)
           || type == typeof(Nullable<byte>)
           || type == typeof(short)
           || type == typeof(Nullable<short>)
           || type == typeof(decimal)
           || type == typeof(Nullable<decimal>)
           || type == typeof(float)
           || type == typeof(Nullable<float>)
           || type == typeof(long)
           || type == typeof(Nullable<long>)
           || type == typeof(uint)
           || type == typeof(Nullable<uint>)
           || type == typeof(sbyte)
           || type == typeof(Nullable<sbyte>)
           || type == typeof(ushort)
           || type == typeof(Nullable<ushort>)
           || type == typeof(ulong)
           || type == typeof(Nullable<ulong>);
    }
}

Public Class RadForm1

    Private provider As LocalDataSourceProvider

    Public Sub New()
        InitializeComponent()
        Me.provider = New LocalDataSourceProvider()
        Me.radPivotGrid1.DataProvider = Me.provider
        AddHandler Me.provider.PrepareDescriptionForField, AddressOf Provider_PrepareDescriptionForField
    End Sub

    Private Sub Provider_PrepareDescriptionForField(ByVal sender As Object, ByVal e As PrepareDescriptionForFieldEventArgs)
        Dim aggregate As PropertyAggregateDescription = TryCast(e.Description, PropertyAggregateDescription)

        If aggregate IsNot Nothing AndAlso IsNumericType(e.FieldInfo.DataType) AndAlso e.FieldInfo.Name = "Product" Then
            aggregate.AggregateFunction = AggregateFunctions.Average
        End If
    End Sub

    Public Shared Function IsNumericType(ByVal type As Type) As Boolean
        Return type = GetType(Double) OrElse type = GetType(Nullable(Of Double)) OrElse type = GetType(Integer) OrElse type = GetType(Nullable(Of Integer)) OrElse type = GetType(Byte) OrElse type = GetType(Nullable(Of Byte)) OrElse type = GetType(Short) OrElse type = GetType(Nullable(Of Short)) OrElse type = GetType(Decimal) OrElse type = GetType(Nullable(Of Decimal)) OrElse type = GetType(Single) OrElse type = GetType(Nullable(Of Single)) OrElse type = GetType(Long) OrElse type = GetType(Nullable(Of Long)) OrElse type = GetType(UInteger) OrElse type = GetType(Nullable(Of UInteger)) OrElse type = GetType(SByte) OrElse type = GetType(Nullable(Of SByte)) OrElse type = GetType(UShort) OrElse type = GetType(Nullable(Of UShort)) OrElse type = GetType(ULong) OrElse type = GetType(Nullable(Of ULong))
    End Function
End Class