Xojo Zipping of Aliases and macOS Apps is problematic

General
1

I have a Method (see below) that is passed a FolderItem and it compresses the file/folder and returns the resulting Zip FolderItem. It is working well, so I’m testing the edge cases and finding it fails with most Aliases and macOS Apps.

If I perform the same zipping via macOS compression or the Shell ‘ditto’ command, it works. But I want Xojo to work 100% of the time so it is cross platform and I can put my apps in the App Stores.

What fails in Xojo Zip:

  1. Compressing the ‘Zip me’ folder produces a zip file, but when you try to open the zip file in the Finder it gives an ‘Error 79 - inappropriate file type or format’ error. If you unzip via Xojo it unzips without complaint, but the file aliases are not working (see next line), yet the aliases within the macOS App ‘Frameworks’ package are working fine!
  2. If I remove the macOS App and try again the zip file is able to be unzipped in the Finder, and the aliases have the correct file length, but are reduced to amorphous versions of themselves.

How can I correctly zip folders containing macOS Apps and both internal and external alias files using Xojo’s Zip command? And how can return the unzipped amorphous alias back to its correct alias state?

…
'Var ZipCompressionType As String = "Best"
'Var tempFolderItem As FolderItem 'source
'Var Dest As FolderItem 'destination
'Var ZipPassword As String
Var tempZipCompression As FolderItem.ZipCompressions
Select Case ZipCompressionType
Case “Best”
tempZipCompression = FolderItem.ZipCompressions.Best
Case “Fast”
tempZipCompression = FolderItem.ZipCompressions.Fast
Case “None”
tempZipCompression = FolderItem.ZipCompressions.None
Case “Normal”
tempZipCompression = FolderItem.ZipCompressions.Normal
Case Else
tempZipCompression = FolderItem.ZipCompressions.Normal
End Select

Dest = tempFolderItem.Zip(Dest, True, tempZipCompression, ZipPassword) 'only Zip the contents not the enclosing folder
End If
…

My source folders to Zip included a Windows Web app build with a few of the items with Alias counterparts, plus an alias to a file that was outside the main folder (Firework.html alias), plus a macOS App (Firework) and an Alias to this App):

Screenshot 2026-02-10 at 2.39.06 pm
Screenshot 2026-02-10 at 2.39.06 pm2758×1790 490 KB

Screenshot 2026-02-10 at 2.49.39 pm
Screenshot 2026-02-10 at 2.49.39 pm980×500 36.8 KB

Screenshot 2026-02-10 at 2.57.47 pm
Screenshot 2026-02-10 at 2.57.47 pm1024×1694 145 KB

Tracker ID: https://tracker.xojo.com/xojoinc/xojo/-/issues/80840

2

I don’t think you can because macOS apps are special kinds of bundles. You can use macOS command line utilities to pack them correctly or launch Archive Utility.app and instruct it to create the zip (I’m a bit foggy on how, but I think I’ve done it before).

Fwiw, this bundle / alias issue is why macOS builds are tarballs (.tar.gz) on Windows.

I have this command laying around from an old build automation. The parameters for ditto here keep the macOS app architecture in-tact. You’d have to ask AI to explain why and how, I’m just trying to help get you operational (I know you were excited about this).

ditto -c -k --sequesterRsrc --keepParent "$MacBuildPath" "$ZipDestionation"

Check to see how the framework handles the ditto zip, maybe it works? If not, you might end up back in the command line or referencing Kaju.

On an unrelated note, the app I had mentioned yesterday was VersionTracker. It helps make changelog html which I thought you might find useful :slight_smile: