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Problem when selecting "Require overrides ... Invoke the Call Parent Method node"

Hi! I'm using LabView for a couple of months now and experience a problem when creating dynamic dispatch VI's for inherited classes with different Connector Terminal Panes. Below is a small description.

 

Environment

Windows 8 64-bit

LabVIEW 2012 12.0.1f5 (32-bit)

 

Steps to reproduce

  1. Open the attached project
  2. Open the properties for Base.lvclass (Right-Click -> Properties)
  3. Go to Item Settings (the Item Settings for Method.vi should be displayed)
  4. Activate "Require overrides of this dynamic dispatch VI to always Invoke the Call Parent Method node"
  5. Click Ok
  6. Answer with Yes or No in the dialog asking, what to do with derived Implementation (Choice here does not matter for the result)
  7. LabView completely closes without any other warning or asking to save unsaved data

What to expect

LabView should not close I guess.

 

Additional Information

This problems starts when the Connector terminal panes are different. In my particular case, I created the VI in the derived class first and realized, that I may need that concept also available in the base class. I therefore created a dynamic dispatch VI in the base class and tried to set the appropriate item settings when encountering the mentioned problem. One way I found to resolve this problem, was to find all derived class VI's with the same name and change the connector terminal pane to match the base class and then modify the item settings.

 

If this was already addressed somewhere or I'm doing something completely wrong, a short note would be appreciated. I hope that the mentioned steps are clear and reproducible.

 

Note: I'm aware that I do not really ask a question here since I was able to completely work around the issue for me. I just wanted to post the encountered problem here in case it not already known and somebody else encounters it. If there is a place better suited for this kind of topic, please give me a hint.

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Hello Locutio,

 

first of all, thank you for your very detailed description. Second, of course this behaviour should not happen. LV should never crash, no matter what you do. I tried your project on my machine and I had the same experience.

Then, to be sure that your file is not corrupt, I programmed a whole new project just as yours, with all the same options and class and file hierarchy. It happened the same way again.

 

As you already said, we could change the connector type to avoid the problem.

Another way is to save all the "method" VIs in the same folder as the project and the other files. Then of course, they have to have different filenames.

When I try it this way, it works no matter what type of connector I use. I can edit the settings without crash.

But if I only change the name and leave the VIs in different folders, the crash happens again.

It seems the VIs really have to be saved in the same folder.

 

Perhaps this could be a solution for you?

 

But in the end, I am going to contact the developers because this issue should be fixed. It is a real bug in my opinion, and it has not been known until now.

 

Thank you again for this information,

have a nice day!

 

Christopher

Christopher W.
Intern Application Engineering | NI Certified LabVIEW Associate Developer (CLAD) | NI Germany
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