New Beta Feature: Improved Compare VIs (“Diff”)

[Christina_R]

Warning: Installing the LabVIEW 2024 Q3 Beta will replace LabVIEW 2024 Q1 if installed. Also, you will need to uninstall LabVIEW 2024 Q3 Beta before installing the release version; upgrading with NI Package Manager will not work.

This feature enables changes to “Compare VIs” (a.k.a. “diff”), which is a common workflow with source code control.

When comparing VIs, you will see the following changes:

1. Block diagram cosmetic changes are not shown by default.
   • To display them, check the “Cosmetic” option under “Block Diagram” in the “Include” options on the right-hand side of the Differences dialog.
2. The first difference is selected when the dialog first opens, and the Differences list will have key focus so that you can use the up and down arrow keys to move through the differences.
3. The diagram will zoom out if needed to show the entire difference.
4. The visual highlighting (red circle) is now a rounded rectangle, to fit the highlighted contents better.
5. The diagram selections are less “noisy.”
6. If a difference is comprised only of front panel position/size or block diagram cosmetic changes, it will appear italicized in the list.
7. The Details list is formatted more concisely than in previous versions, reducing the need to scroll.
8. The Differences and Details lists support word-wrapping so that lengthy descriptions aren’t cut off.
9. A new command in the overflow menu allows you to swap the positions of the VIs being compared.
10. There will typically be fewer Differences listed than in previous versions, due to improvements in the comparison algorithm.

This illustration shows some of the improvements:

This is the same comparison in an earlier version of LabVIEW:

Section 1. How to Use the Feature

There are two ways to “diff” VIs interactively:

1. With source control
   1. Use LVCompare.exe configured as your diff tool.
2. Manual testing
   1. Open two revisions of a VI that you want to compare. The VIs will need to have different file names for LabVIEW to open them at the same time.
   2. From the menu, select Tools»Compare»Compare VIs.

Section 2. Requested Feedback

Please report any unexpected VI diff results here. If possible, please provide the VIs or a screenshot of the comparison.

Section 3. Known Issues

1. The new command in the overflow menu that allows you to swap the positions of the VIs being compared can crash LabVIEW if you are comparing VIs opened by LVCompare.exe.
2. On Linux, the Differences dialog doesn’t have key focus when it first opens.
3. On Linux, clicking on the Differences window and pressing a key can crash LabVIEW.