lib/proforma/compiling/aggregation.rb in proforma-1.0.0 vs lib/proforma/compiling/aggregation.rb in proforma-1.0.1

@@ -25,10 +25,10 @@
 
       def add(records)
         records.each do |record|
           aggregators.each do |aggregator|
             property  = aggregator.property
-            value     = evaluator.value(record, property)
+            value     = property.to_s.empty? ? nil : evaluator.value(record, property)
             name      = aggregator.name
 
             entry(name).add(value)
           end
         end