Filtering difference items

To support filtering difference items from database-generated difference items, such as those used by the policy change job, perform the following tasks.

1. In your new Gosu class LOBDiffHelper, create a method that overrides filterDiffItems.
2. In filterDiffItems, remove all difference items you do not want to display. Depending on what you are doing, you might be able to use simple logic using blocks.
3. Call the filterDiffItems method from filterDiffItems in PolicyPeriodDiffPlugin, as shown in the bold line in the example below.

   // Filter diffs by LOB if this is not for integration or out of sequence jobs
   if (    reason != DiffReason.TC_INTEGRATION
       and reason != DiffReason.TC_APPLYCHANGES) {
     // Add diffs for PolicyPeriod attributes
     if (currentPeriod.Renewal == null and reason != null) {
       diffItems = addPolicyPeriodDiffItems(currentPeriod, currentPeriod.BasedOn, diffItems)
     }
   
     // Filter diffs by LOB
     for (line1 in currentPeriod.BasedOn.Lines){
       var line2 = currentPeriod.Lines.firstWhere( \ p -> p.Subtype.Code == line1.Subtype.Code )
       if (line2 != null) {
         diffHelper = line1.createPolicyLineDiffHelper(reason, line2)
         if (diffHelper != null) {
           diffItems = diffHelper.filterDiffItems(diffItems) 
         }
       }
     }
   
     // Remove PolicyPeriod attribute diffs if this is a rewrite job
     if (currentPeriod.Rewrite != null) {
       diffItems.removeWhere( \ d -> d.Bean typeis PolicyPeriod )
     }
   }

Because there are several reasons for calculating differences, you can vary your application logic based on the difference reason. The difference reason is a DiffReason enumeration passed to the PolicyPeriodDiffPlugin plugin method compareBranches. Choices are defined in the DiffReason typelist and include TC_INTEGRATION, TC_MULTIVERSIONJOB, TC_PREEMPTION, TC_POLICYREVIEW, TC_COMPAREJOBS.