ChangesetReader and multiple changes.

[manderson88]

I am using this to process the changes to my iModel that happen when using PlantSight or OPPID.

         using reader = ChangesetReader.openGroup({ changesetFiles: changeSetFiles, db: iModelDB, propFilter:PropertyFilter.All,rowOptions:{classIdsToClassNames:true}});
        reader.setOpCodeFilters(new Set(["Deleted", "Updated", "Inserted"]));

        using pcu = new PartialChangeUnifier(ChangeUnifierCache.createInMemoryCache());

        while (reader.step()) {
            pcu.appendFrom(reader);
        }

        var processedCounter = 0;
        var changeCollection: any[] = [];

        for (const instance of pcu.instances) {
            Logger.logInfo(loggerCategory, "Instance :" + instance);
            var cname = instance.ECClassId;
            if (cname.startsWith("ProcessFunctional")) {
                var changeItemInfo = new ChangeItemInfo(instance.ECInstanceId, cname, instance.$meta.op, instance.FederationGuid, instance.CodeValue, "");

                if(undefined === changeCollection.find((item:ChangeItemInfo)=> item.equals(changeItemInfo)))
                    changeCollection.push(changeItemInfo);
            }
            processedCounter++;
        }

I need to update our internal data based on the cloud model. When the user creates a component, commits that change. Then deletes that same component and commits that change. Then I "sync" my side by building a changeset that has the two commits. What I am seeing is the first time I process the set I see the new component only and the second time I process the same set I only see the deleted component. Is there something that I can do to avoid this issue? Since I get updates on a 10 minute timer and there could be any number of changes that happen in this window. Any thoughts or suggestions?

Mark Anderson

[soham-bentley]

I did not understand the scenario completely. Would love to connect with you and help you out more.
As far as I have understood, answering based on that:

Lets say we add the component and create a changeset file for the change, that changeset file may include INSERT ops in 2 - 3 tables and then when we will delete the component and create another changeset file, that changeset file will include DELETE ops in the same 2 - 3 tables. Now when we open the changeset files as a group, we on the native side squash the changes(that is the behavior of changesets in SQLite) so the net change for the Insertion and deletion is actually nothing or empty.
If we want to track changes per changeset file we should use the openFile method of the ChangesetReader api.

We can discuss about the exact problem you are facing more over on teams(or here) and figure out a way forward.

[soham-bentley]

Yes sounds good to me. We can also use this discussion to get more details regarding the issue. And then create a backlog if needed.

[manderson88]

As to more information about this issue. I agree that there should be a net 0 change since the part added/changed was subsequently deleted. But what I end up seeing (and this is the odd part) is that the first time I try the change group it shows as added. If I run the group again it now shows up deleted. HTH, this is the last bit I need to solve to move on with other activities (and I am being pressed to get this update out before API shutdowns of the "old" code.

thx,
marka

[khanaffan]

ChangesetReader.openGroup() should squash changes and INSERT + DELETE = NOOP.

@soham-bentley can we verify on our side with a test to ensure this behavior is kept in new API. Also share or point to branch you push test to on this issue, so we can see if that what user have.

[soham-bentley]

It is working as expected INSERT + DELETED = NOOP .Added a test