AttributeAccumulator

From Fmepedia

AttributeAccumulator is a Workbench Transformer.

Combines feature attributes. One feature is output for each unique combination of values of the attributes specified in the GROUP BY. The output feature will have no geometry.

If Yes is chosen for Input is Ordered by Group, then the transformer will output all the aggregates it has accumulated so far every time the values of the Group By attributes change from one feature to the next.

If no GROUP BY attributes are specified, a single feature is output with all of the input attributees combined together on it.

If the optional list name is supplied, a list of all the attributes of each feature that is combined to create the output feature is made.