
154 CHAPTER SEVEN
Filtering and Grouping
A client can specify how the raw EPC observations should be processed before they are
included in the report. The ALE specification provides two distinct mechanisms for event
processing: filtering and grouping. Filtering provides capabilities to tune into specific pat-
terns in the event data. Grouping provides means to group data collected from different
Readers and over multiple event cycles. The ECFilterSpec and ECGroupSpec are provided
for filter patterns and grouping patterns, respectively. An ECSpec can contain multiple
report specifications, and a client can specify a filter specification (ECFilterSpec) and a
group specification (ECGroupSpec) as a part of every report specification (ECReportSpec):
ECReportSpec
reportName : string
reportSet : ECReportSetSpec
filter : ECFilterSpec
group : ECGroupSpec
output : ECReportOutputSpec
reportIfEmpty : boolean
reportOnlyOnChange : boolean
<<extension point>>
Filters provided by the ECFilterSpec should be applied to the raw EPC observations com-
ing from Readers before grouping patterns are applied:
ECFilterSpec
includePatterns : List
excludePatterns : List
<<extension point>>
The ECGroupSpec specifies how filtered EPCs should be grouped for reporting:
ECGroupSpec
patternList : List
<<extension point>>
Filtering
Clients can specify filtering schemes with the help of two pattern lists: includePatterns and
excludePatterns. ...