Add option to generate xml:ids for each element (note)

[WolfgangDrescher]

When importing MusicXML files in verovio it will convert the score to MEI and randomly generated xml:id attributes will be added to all elements (such as measures, staves, layers, notes, rests, etc.). It would be useful to have an option in MuseScore to add xml:id attributes manually for each element so the IDs can be used in MEI as well. Maybe an option to automatically generate random xml:id for all elements could be useful as well. Once an element has a xml:id assigned it should keep the id when the note is modified.

Have a look at the ongoing discussion on rism-digital/verovio#3301

[shoogle]

Element IDs can be very handy, but they cause problems when comparing files using text-based diff utilities. We actually had element IDs in MuseScore in the past (only for spanner elements like slurs and hairpins, etc.) but we got rid of them for this very reason.

I can't say that performing a text diff is a particularly important use-case for us, so it's possible that we will see element IDs in MuseScore again someday, but we would look for other solutions first.

If IDs are necessary in MEI then I could imagine a compromise solution where we avoid having IDs in MuseScore until the score is exported for the first time, at which point there could be the option to generate IDs and potentially have them preserved in the MuseScore file to ensure the same IDs are used again on the next export. Also, if a score was imported with IDs then those existing IDs could be preserved.

---

To illustrate the problem with IDs and diffs, imagine you and I create separate transcriptions of Beethoven's Für Elise, and now we want to compare our transcriptions to see if there are any differences.

• If the files contain random IDs then any semantic differences between the files will be obscured by the huge false diff created by all the changed IDs.

• If the IDs are systematic based on the time or order in which elements were added to the score, then the IDs will be different unless we both added the same elements at the exact same time or in the exact same order, which is highly unlikely.

• If the IDs are systematic based on the location of elements in the score (e.g. staff number, measure number, beat position, etc.) then the IDs will be the same in both files unless one of us accidentally added/skipped a measure in our transcription, in which case all IDs after that point will be different, which would be problematic if this occurs early in the file.

Of course we could simply filter out the IDs before we do the comparison. But let's imagine the two files are actually the same file stored on different branches of a Git repository (or in different commits on the same branch) and we need to compare them using Git's built-in diff tool (or perhaps the online GitHub viewer). In this case we wouldn't have the option to strip IDs before we do the comparison.