unintentional deletion of MIDI files

Tamarindo18

When a MIDI file is assigned to a song, if we later want to remove it, ST4 physically deletes the file from the iPad. I don’t think this should happen, since that file could be used for something else. I believe it should simply unassign the MIDI file from that song, but not delete it from the iPad (imagine you just made a mistake when assigning it and selected the wrong one—when you try to change it, the one you selected first gets deleted from the iPad).

AnthonyB

ST4 creates a folder for each song, and copies the assets (tracks, MIDI file, etc.) into that folder.
There is no 'sharing' of assets between songs. If you have a common MIDI file you are adding to multiple songs, then a copy of that file will be in each song folder. Therefore, deleting it from one song has no absolute impact.

Just in case this is something you are doing, as a general rule of thumb it is not recommended to manually manipulate the Stage Traxx 4 folder on your iPad, and that includes using it as a source for adding/reusing assets. It is recommended you always add tracks, MIDI, lyrics, etc. from outside of this folder structure and let ST4 manage its folders and their contents.

peter

ST4 supports sharing assets between multiple songs. That happens when you duplicate a song. Assets are only deleted when no other song is using that asset.

Tamarindo18

peter Yes, but imagine if the MIDI file that ST4 deletes is also used by another app to control anything else unrelated to ST4 (camera control, lights, synthesizers...). What I mean is that it’s risky for ST4 to decide to delete a file that it didn’t generate itself and that has been assigned to a song for some reason. The most logical thing would simply be to unassign it from the song and leave everything as it was in the iPad’s file system—not to make the decision to delete a file without giving any option to avoid doing so. In other words, if you want to unassign the MIDI file, you know you’re going to lose it. Imagine you’ve only made a small mistake that can be fixed by editing the MIDI file and changing a single value of a command in some external editor, then simply reimporting it. Deleting the MIDI file complicates everything.

AnthonyB

OK, aside from the scenario of if you duplicate a song 🙂

Now, that's a whole different potential can of worms!

peter

Other apps always need to ask permission to access files in the Stage Traxx folder. Don't share files between apps like that. iOS is built with a security models that relies on the fact that each app has its own data files.

And even if ST4 would not delete that file, it is no longer included in backups or synced. So at some point you will definitely lose that file.

Tamarindo18

Okay, now I get it. I've confirmed that ST4 ONLY deletes the MIDI file if it's located inside the ST4 directory, but leaves it alone if it's outside. That makes sense from the perspective of keeping the ST4 directory structure tidy, and there's a very easy solution: if I don't want the MIDI files to be deleted, I just need to save them somewhere else and import them from there.

AnthonyB

Tamarindo18 I've confirmed that ST4 ONLY deletes the MIDI file if it's located inside the ST4 directory, but leaves it alone if it's outside.

Yep, as I said earlier, when you add a MIDI file (or audio file) to a song, ST makes a copy of that file and puts it into it's internal folder structure, where there is a folder for each song. When you delete a MIDI file (or audio file) it is deleting from ST internal folder structure.
This is why it is recommended to always add files from outside of ST (local storage, cloud drive, USB drive, etc.) so that all your audio and MIDI files inside of ST are essentially copies from wherever you maintain all your song assets.