Direct "global replace" using VI hierarchy.

[altenbach]

Sometimes we have a big application that uses "MyTweakSubVI_A.vi" in many places. One morning we wake up and discover that this subVI could be made much better, so we wire up "MyTweakSubVI_B.vi" and do a few sandbox tests to verify that it operates correctly. After we are satisfied, comes the time where we need to replace every instance of  "...SubVI_A..." with "...SubVI_B...".

The typical way would be to go to the VI hierarchy and "right-click...find all instances...select all...pick the replacement...replace all selected". Tedious!

Wouldn't it be easier if we could just right-click...replace (in the VI Hierarchy!)...pick the new VI and it would globally replace the old VI with the new VI.

IDEA: The VI hierarchy should have a "right-click..replace" menu entry that would directly do a global replacement of all instances of the selected VI.

(Of course there should be some protection in place so that anything in VI lib is not modified)

[JackDunaway]

altenbach,

Do you think it would be easy to CTRL+Z this operation? If not, I could see this operation causing much more heartache than it solves.

Jack

[altenbach]

Well, to undo you would just repeat the operation and point to the old VI again. 🙂

[altenbach]

While it is relatively intuitive (at least to me) that the icon in the hierarchy stands for all instances of a subVI, the command could be worded to make the function even clearer. Instead of "replace..." it could e.g. say "replace all instances...". There could even be a confirmation dialog.

[JackDunaway]

Being the devil's advocate here:

The operation you suggest could screw you, though. If you are using a combination of 10 SubVI_A's and 10 SubVI_B's throughout your project, and realize, "Hey, I think I can replace all _A's with my _B's." Now, you have 20 instances of SubVI_B in your project.

"Whoops, that won't work! I need to revert all of the ones I just replaced back to SubVI_A!" Uh-oh. Now you have 20 instances of SubVI_A when you meant to go back to the scenario of 10 and 10.

Being able to CTRL+Z a bonehead (or even deliberate!) programming move saves each of our tails every day. If we can't CTRL+Z, I don't want this feature added - it could prove catastrophic.

(Note: I am FAR from the type who thinks software should be dummy-proofed. If you consistently make dumb moves, you should be punished by losing your code. There's no way LabVIEW can predict what moves you made unintentionally. That's why there's CTRL+Z - it doesn't have to predict what you accidentally did - it just keeps up with what you did. If this Idea would be trivially easy to implement for NI with undo, I would be "for" this idea. Without CTRL+Z, however, the negative impacts outweigh time savings.)

[altenbach]

It won't be any more or less dangerous than the "replace all" button in the "find all instances" dialog. 🙂

If you save you work regularly, just exit without saving or revert the relevant VIs from the menu if you regret the replacement. I have not tried to see if undo would work, maybe it even does? 😉 

(In the very old days, I would just close LabVIEW, rename the subVI, and re-open the toplevel. 🐵

[Intaris]

Three words:

Source Code Control