Open Radar

 
Summary:
My app provides a QuickLook generator supporting two different UTIs, but when I have another app installed that also has a QuickLook generator for the same types, it seems to get preference (it’s perhaps alphabetical by qlgenerator name (“BetterZip” vs. “Comickaze”). I tried making my own app the default app to open those extension types, and that didn’t help. It seems like there should be a way for an end user to specify which app provides QuickLook previews for a given file type

Steps to Reproduce:
1. Install Comickaze v1.2.4 or later (unreleased at this time - v1.2.3 on the Mac App Store is broken. I can provide a prerelease copy if it would help)
2. Install BetterZip
3. Press the spacebar on a CBR or CBZ file in Finder
4. Get Info on the archive
5. Choose Comickaze as the “Open with” app
6. Click “Change All…”
7. Press the spacebar on the archive in Finder again

Expected Results:
The Comickaze qlgenerator may or may not be selected for step 3, but it definitely should be for step 7 (or there should be a way to use qlmanage or another tool to associate a UTI with a specific generator)

Actual Results:
BetterZip generates previews for steps 3 and 7

Version:
10.12

Notes:
I also notice when running qlmanage, that BetterZip’s UTI definitions are also being used for those file types that both apps support until I delete the app. That may be a cause or a symptom, though I’m not sure which

Update 10/31/2017 from Apple Developer Relations:

Engineering has provided the following feedback regarding this issue:   The documentation states that if two generators claim the same file types behavior is undefined regarding which one is called.