public static int?GetCount <T>(this AggregationsHelper aggs, Expression <Func <T, object> > fieldGetter, Expression <Func <T, object> > filterRule = null)
{
var aggName = fieldGetter.GetAggName(AggType.Count);
if (filterRule == null)
{
var itemsTerms = aggs.ValueCount(aggName);
if (!itemsTerms.Value.HasValue)
{
return(null);
}
return((int)itemsTerms.Value);
}
else
{
var condAggName = filterRule.GenerateFilterName();
var filterAgg = aggs.Filter(condAggName);
var sumAgg = filterAgg.Sum(aggName);
if (!sumAgg.Value.HasValue)
{
return(null);
}
return((int)sumAgg.Value);
}
}