Type descriptor & Downcasting a refnum

[Sebh]

Hi,

This question is a re-opining of this old thread, which ends by an non-answer ... (since the proposed solution is supposed to disapear one day)

http://forums.ni.com/t5/LabVIEW/LabVIEW-8-2-control-refnum-type-descriptor-missing/m-p/592060/highli...

So how do we actually downcast a generic refnum ( command in the following VI example ) to it's initial type ?

What I don't get is that typeDesc property node disapeared , but type descriptor still exists (and will obviously always be , see https://www.ni.com/docs/en-US/bundle/labview/page/type-descriptors.html )

So what ?

OpenG libraries use the type descriptor for lot of operations but for refnum, it seems to stop downcast to the generic "VI server" class.

(in case you wonder, I'm basically looking the same things the OpenG_Variant_Configuration_File library does, but instead of using cluster of data, I want to use cluster of references to data)

I suppose (and hope) there is a very simple replacement of the old deprecated property node, or solution to this problem, but I cannot find it.

Any help ?

[Sebh · Accepted solution]

Ok, been looking for this during hours, but of course I found the obvious answer right after having asked.

Just need to "unpack" the inner type descriptor by using Value property node... Oo ...

Posting answer to my own problem just in case some else one day wonders the same.

[tst]

While the type descriptor property is deprecated, you can still get this data from the reference. The Class Name property, as you saw, gets you some of the way there. For the more specific stuff, you can go one of two ways - either using specific properties (like the private Representation property, which will give you the numeric's info) or using the Value property and then using the VIs in vi.lib\Utility\VariantDataType to get the specific data and format it. There should also be a single VI for getting the exact type data.