5 replies to this topic

[neil]

Hi All,

Can anybody explain to me why it is not possible to create a DVR to a class in a VI outside of that class?

Of the two images attached the first one (with the broken wire) is from a VI that is outside the class, the one that is not broken is from a VI that lives inside the class.

The error message is Polymorphic terminal cannot accept this data type

Does the DVR have to be created inside a class member VI?

Attached Thumbnails

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[mike5]

It's a property setting:



Br, Miha

[neil]

Thanks Miha,

Now that you mention it, I do remember changing this before when I had this problem last time, but I totally forgot about it!

[jgcode]

Thanks Miha,

Now that you mention it, I do remember changing this before when I had this problem last time, but I totally forgot about it!

In case you are wondering what is the point of this feature:
One of the reasons for doing this is so you have the ability to force the user to use your constructor method as opposed DVR'ing the object with x state.
This maybe important sometimes when you need to guarantee that any methods/setup that are required to run are indeed run, then you can DVR the object -> you have complete control.

[neil]

In case you are wondering what is the point of this feature:
One of the reasons for doing this is so you have the ability to force the user to use your constructor method as opposed DVR'ing the object with x state.
This maybe important sometimes when you need to guarantee that any methods/setup that are required to run are indeed run, then you can DVR the object -> you have complete control.

thanks Jon. My OO experience is quite limited, so I have not really ever needed to start mucking about with those checkboxes. Your explanation does make sense though. Most of the apps I develop are really 1 person projects, so I have never really had to think too much about someone "misusing" any of my classes.

[Aristos Queue]

It's not just someone else misusing. It's also about making your own debugging easier as your code base expands.