My application has many aggregate fields that need to be updated when any related record is changed, added or deleted. The relationships and calculations are somewhat involved, so I created a class that handles all of the calculations for all of the related tables. There is some SOQL and DML overhead involved in the calculations, so the class handles everything in bulk.
I would like to have the updateAll() method on this class run no more than once per request on all of the records that have been added to its queue. But, there doesn't appear to be "deconstructor-like" functionality in APEX that would automatically get called right before this calculator object was destroyed.
What is the best way to implement this pattern in APEX?
Here's what I did. I created a Calculator class that recalcs every related aggregate/calculated field in a ~10 table/object relationship. I used triggers on each of those objects to make the calculator class run on the set of related object families to the objects that were changed. I used a static variable on the calculator class to check if the calculator was running in each of the triggers so that they would only call the calculator if it wasn't currently running. It works well enough. A bit inefficient, but stays below governor limits and works in bulk very well. And, I can grow with it...