[JSR223] Trigger "Item GROUP_NAME received update" does not work

[rlkoshak (Rich Koshak)]

@rossko57

Before the availability of Member of triggers, we used to have all sorts of troubles in DSL because a single member change could fire a burst of Group updates. Something to do with iterations calculating Group state.

The ugly way we used to figure out triggeringItem before there was a triggeringItem implicit variable and Member of Rule triggers was as follows:

• save all the members of the Group to persistence
• trigger the Rule on updates to the Group
• set up a Rule latch so only one instance runs at a time (optional)
• sleep for long enough for Persistence to write the new state to the DB
• val triggeringItem = MyGroup.members.sortBy[ i | i.lastUpdate ].last or something like that, it’s been years since I’ve seen it

And indeed, the Rule would trigger n-1 times where n is the number of members of the Group.