Changing UDT Parent Type

[levi_jacobs]

I’ve noticed in 8.1.3 that I can no longer change the UDT parent type on a UDT instance. Was this an intentional change? (I found this feature very convenient!)

I see this entry in the release notes, but i thought it only applied to nested UDT instances.

[nminchin]

Yep, it's broken and was applied incorrectly to all UDT instances instead. Super frustrating as in order to change the parent now you have to delete the tags altogether and reimport...

I raised a bug with support but haven't heard anything from them and it's been almost a month, also posted below

[IGN-2416] 8.1.4-RC1 Can't change parent data type of non-nested UDT instance

I’m trying to change the parent UDT type of a whole bunch of UDT instances, however I can no longer do this. I know there was a change that was going in at some stage that was going to stop nested UDT instances within a base UDT definition from being changed (makes sense), but this change is affecting the base level as well. Error is: Bad_Unsupported("Cannot change typeId of inherited tag These tank instances below are instantiated within the Tanks folder, and their parent data type is greyed…

[kcollins1]

@levi_jacobs, You are correct, the change in behavior here was in order to fix an issue related to overriding of a Parent Data Type within a nested UDT instance as well as improper behavior related to bindings against the Parent Data Type. For example:

However, in taking a broader look at things, this ended up reaching a bit further into locking out the ability to change it at an instance level, which while perhaps unintended, did work before. With how properties are stored with a tag, I think it is probably better this way, as changing the parent data type of a tag instance would result in a bunch of potentially stale data/properties being stored with the tag object (since it now has a new shape).

There is an open ticket to address the import-with-overwrite to change the tag definition.

[nminchin]

Most of the time, if I need to change a parent type, both udts are going to have exactly the same udt parameters, so this isn’t an issue. I imagine it would be the same for most users. If you’re changing the instance to a completely unrelated one, then you should probably be creating a new instance anyway

[levi_jacobs]

Ok. Thanks for the response.

[julie.rhoads]

Is there an update on this being allowed again?

[kcollins1]

Just based on some functional testing against 8.1.13, it looks like the ability to change the Parent type of a standalone UDT instance is working. Note that the original change mentioned by OP still applies, Changing an Inherited UDT Instance’s Parent Data Type is [not allowed].

[julie.rhoads]

thank you! i’m on 8.1.11 so let me try upgrading.