If a system event attribute occurs several times in a system event, there is no guarantee that the last value read will be transferred. To transfer all values for attributes that occur several times in a system event, you can specify the multieventattributetype XML element instead of the attribute XML element in the mapping configuration. All values of system event attributes identified in this way are concatenated with a separator (semicolon by default). Use the optional delimiter XML attribute to specify a separator other than the default.
Using multiple system event attribute values makes it easier to merge parallel process paths if you write all merge keys for the preceding fragment to the system event file as multieventattributetype attributes.
Example
System event file extract
...
<event>
<attribute type="EVENTTYP">Change customer order</attribute>
<attribute type="THIS_KEY">3</attribute>
<attribute type="PREV_KEY">1</attribute>
<attribute type="PREV_KEY">2</attribute>
<attribute type="USER">Team A</attribute>
</event>
...
Mapping file extract
...
<attributemapping>
...
<!-- Mapping Event Start BEGIN -->
<objectattributes objectname="EVT_START" graphid="FRG_CATCH_ALL">
<attribute ppmattributetype="AT_OBJNAME">
<eventattributetype>EVENTTYP</eventattributetype>
<value> to be done</value>
</attribute>
<attribute ppmattributetype="AT_ID">
<eventattributetype>AT_PRCNO</eventattributetype>
</attribute>
<!-- Mulivalue Mapping -->
<attribute ppmattributetype="AT_KEY">
<multieventattributetype delimiter=";">PREV_KEY</multieventattributetype>
</attribute>
...
</objectattributes>
...
The AT_KEY attribute generated for the EVT_START event is assigned the value 1;2. If the merge is configured accordingly, two merge keys will be generated for this event.