[Solved] Custom aggregate functions throws System.ArgumentOutOfRangeException

[Thomas LEBRUN]

Hi,

I'm using the latest internal build with a custom aggregate function defined as belowed:

public abstract class IndexedAggregateFunction : AggregateFunction
    {
        static MethodInfo s_genericSelect = typeof(Enumerable).GetMethods().Where(m => m.Name == "Select" && m.GetParameters()[1].ParameterType.GetGenericArguments().Length == 2).First();

        public override string FunctionName
        {
            get
            {
                return base.FunctionName;
            }
            set
            {
                base.FunctionName = value;
            }
        }
        public override string ResultFormatString
        {
            get
            {
                return base.ResultFormatString;
            }
            set
            {
                base.ResultFormatString = value;
            }
        }

        protected override string GenerateFunctionName()
        {
            return base.GenerateFunctionName();
        }

        public int Index { get; set; }

        protected abstract System.Linq.Expressions.Expression CreateAfterSelectionExpression(System.Linq.Expressions.Expression selectedEnumerableExpression);

        protected System.Linq.Expressions.Expression GetDoubleSelectorExpression(System.Linq.Expressions.ParameterExpression param)
        {
            var propInfo = typeof(DataRowContainer).GetProperty("RawData");
            var methodInfo = typeof(ObservableCollection<object>).GetMethod("get_Item");
            return System.Linq.Expressions.Expression.Convert(
                System.Linq.Expressions.Expression.Call(
                    System.Linq.Expressions.Expression.MakeMemberAccess(param, propInfo)
                    , methodInfo, System.Linq.Expressions.Expression.Constant(Index)),
                typeof(double?));
        }

        protected System.Linq.Expressions.Expression GetListOfDoubleExpression(System.Linq.Expressions.Expression param)
        {

            var methodInfo = s_genericSelect.MakeGenericMethod(typeof(DataRowContainer), typeof(double?));

            var selectorParam = System.Linq.Expressions.Expression.Parameter(typeof(DataRowContainer), "item");

            return System.Linq.Expressions.Expression.Call(methodInfo, param, System.Linq.Expressions.Expression.Lambda(GetDoubleSelectorExpression(selectorParam), selectorParam));

        }


        protected System.Linq.Expressions.Expression GetAggregatedListOfDoubleExpression(System.Linq.Expressions.Expression param)
        {
            return CreateAfterSelectionExpression(GetListOfDoubleExpression(param));
        }


        public override System.Linq.Expressions.Expression CreateAggregateExpression(System.Linq.Expressions.Expression enumerableExpression)
        {

            return GetAggregatedListOfDoubleExpression(enumerableExpression);
        }
    }


    public class IndexedSumAggregateFunction : IndexedAggregateFunction
    {
        protected override System.Linq.Expressions.Expression CreateAfterSelectionExpression(System.Linq.Expressions.Expression selectedEnumerableExpression)
        {
            var method = typeof(Enumerable).GetMethod("Sum", new Type[] { typeof(IEnumerable<double?>) });

            return System.Linq.Expressions.Expression.Call(method, selectedEnumerableExpression);
        }
    }

It works fine but sometimes, when i call CalculateAggregates, i get the following error:

System.ArgumentOutOfRangeException: Index was outsite the limit of the array

With the following stacktrace:

   à System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
   à System.ThrowHelper.ThrowArgumentOutOfRangeException()
   à System.Collections.Generic.List`1.get_Item(Int32 index)
   à System.Collections.ObjectModel.Collection`1.get_Item(Int32 index)
   à lambda_method(ExecutionScope , DataRowContainer )
   à System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   à System.Linq.Enumerable.Sum(IEnumerable`1 source)
   à lambda_method(ExecutionScope , IGrouping`2 )
   à System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   à Telerik.Windows.Data.QueryableExtensions.Aggregate(IQueryable source, IEnumerable`1 aggregateFunctions)
   à Telerik.Windows.Controls.GridView.GridViewDataControl.CreateAggregateResults()
   à Telerik.Windows.Controls.GridView.GridViewDataControl.CalculateAggregates()


Any ideas ?


Thanks !

[Thomas LEBRUN]

Hi,

Anyone got an idea ?


Thanks !

[Stefan Dobrev]

Hi Thomas,

It seems that the Index you are using in your aggregate expression is throwing the exception. For example one of your data items (DataRowContainer) the RawData property may has less number of elements than the index you are trying to access. This way an ArgumentOutOfRangeException will be thrown.

Greetings,
Stefan Dobrev
the Telerik team

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[Thomas LEBRUN]

Hi Stefan,

I was using a foreach loop to add my custom aggregate function and in the loop, i called CalculateAggregate (not the best way to optimize performances :)

After move the call to CalculateAggregate outsite (after) the foreach loop, it seems to works fine.


Thanks !