Compound Close References

[Daniel-E]

When using extensive numbers of property and invoke nodes (for example, using the TestStand API) it's very common to end up with many references that need to be closed. This leads to structures like this:

It would be very convenient if we had a Compound Close References node that we could wire multiple references into. Since order often matters with closing references, the node could execute top-down once all references are available at the inputs. This would substantially clean up block diagrams and make API code a bit easier to follow. For example, the above code could just be replaced with:

[D-Cubed]

Perhaps it could have an icon like this:

[crossrulz]

Just make sure you still have the Error In and Error Out.

This idea would also take care of this idea: http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Reduce-the-size-of-the-Close-Reference-VI/idi-p/155858...

[Daniel-E]

Agreed crossrulz, it would need an Error In and Error Out both for data flow and for any errors that could result from closing the references.

[CMal]

This may not be exactly what you're looking for, but rememeber that Close Reference can accept an array of references.

[PaulG.]

Would we not want this to close references from the bottom-up (lower-level to higher-level) in order to retain proper closing sequence? I rarely close refs by array since the closing sequence matters. Or does it? If I remember correctlly closing a higher-level reference before a lower-level wil cause an error message.

[Intaris]

Reverse order would seem to be my taking on it also.  When do we ever need a different scheme for closing references?

The Icon for the primitive would perhaps need a qualifier (right-click) to set the direction coupled with an arrow visible at all times (because I really hate hidden settings).

[ouadji]

@ CMal :

"...rememeber that Close Reference can accept an array of references."

yes, but not in all cases.

[Darren]

Am I being a troublemaker if I point out that closing the Panel reference in the previous screenshot is completely unnecessary? 😉

[ouadji]

@Darren :

Could you explain to me why closing the Panel reference is unnecessary?
in advance, thank you very much Darren.

(Are there other references which don't need to be closed?)

[Darren]

This document gives a pretty good summary of all the use cases surrounding closing references in LabVIEW:

Closing References in LabVIEW

When this document was originally released, I lobbied for stronger wording regarding the closing of GObject references (panels, diagrams, and anything that lives on them)...mainly, that it's not necessary. The code below runs without error and returns the MasterRect property at both calls, despite the panel reference being closed prior to the second call:

This is because closing a GObject reference is a no-op...LabVIEW will clean up all open GObject references to objects in a VI whenever the VI reference is closed.