Constant typedef description missing

[Darren]

FYI to anyone following this thread, NI is investigating the possibility of fixing this issue in a future LabVIEW release. Also note that it is now being tracked under a new number, Bug 3352943.

[Christina_R]

This issue has been fixed in LabVIEW 2026 Q1.

[ImreSzebelledi]

I would not say fixed, instead it is some kind of hack. Now control/indicator descriptions are linked to the original typedef and they are updated with it as well, but constant decriptions are only copied when they are placed, and do not update with the change of the typedef descriptions. 

[billko]

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@ImreSzebelledi wrote:

I would not say fixed, instead it is some kind of hack. Now control/indicator descriptions are linked to the original typedef and they are updated with it as well, but constant decriptions are only copied when they are placed, and do not update with the change of the typedef descriptions. 

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The description is not part of the data type, so it doesn't propagate.

[ImreSzebelledi]

Then why does it propagate for controls/indicators? This half baked solution creates more problem than it solves because it can cause outdated documentation for constants which is worse than no documentation at all.

[billko]

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@ImreSzebelledi wrote:

Then why does it propagate for controls/indicators? This half baked solution creates more problem than it solves because it can cause outdated documentation for constants which is worse than no documentation at all.

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It propagates with controls and indicators because there is a description property. Up until I guess the latest LV version, block diagram constants didn't even have a description property.

Now that I think of it, it does seem a bit half-baked, like they didn't account for it not propagating. Just like hiding the iteration terminal on the FOR loop still makes wires go around the invisible terminal.

[Christina_R]

I think there's confusion here about strict type definitions vs type definitions.

Type definitions only get data type information. Strict type definitions update all aspects of the control.

But there's no such thing as a strict typedef constant. Constants that link to strict type definitions only get the data type.

[ImreSzebelledi]

Actually you can create 4 different types of descriptions for a typedef even in LV 2020. 
1. You can create a description in control properties (ctrl+I) -> only shown in context help if you select the control in project explorer.
2. You can create a description during front panel edit of the typedef  (right click on the control istelf and "Description and tip") -> only shown in context help for front panel controls and indicators placed on a VI FP
3. You can create a description for Typedef constant (right click on the constant and "Description and tip") -> will be shown in the context menu when hovering the mouse over the constant
4. You can create a description for Typedef constant (right click on the constant -> Properties -> Documentation) -> Never will be shown in context help.

Good luck writing a description for a typedef. Compare this to a VI description which can only be edited in one place only (Vi properties) -> edit: I have checked and #3 also applies to placed VI instances, but it is not displayed in the context help.

What has changed in LV 2026 Q1 is now they copy the text edited in #2 to #3. 
Maybe it seems like I am just ranting, but I was looking forward to the solution, because we are relying on typdefs a lot, and would have been nice if we could create proper descriptions for them.