public static AggregationContainerDescriptor <T> CountBy <T>(this AggregationContainerDescriptor <T> agg, Expression <Func <T, object> > fieldGetter, Expression <Func <T, bool> > filterRule = null) where T : class
{
var aggName = fieldGetter.GetAggName(AggType.Count);
if (filterRule == null)
{
return(agg.ValueCount(aggName, x => x.Field(fieldGetter)));
}
var filterName = filterRule.GenerateFilterName();
agg.Filter(filterName,
f =>
f.Filter(fd => filterRule.Body.GenerateFilterDescription <T>())
.Aggregations(innerAgg => innerAgg.ValueCount(aggName, field => field.Field(fieldGetter))));
return(agg);
}
