File suffix and type association

[corradoventu]

SweetHome3D uses files with suffix .sh3d but having internally a Zip format.
On one partitions on my PC I have SweetHome3D installed via deb package, on a different partition I have the snap version of SweetHome3D. Both partitions are in Ubuntu Cosmic.
For the deb version the default application for .sh3d files is SweetHome3D while for the snap version the default is ArchiveManager.
If I select FileProperties-OpenWith for a .sh3d file
on the 1st install (deb) I see: Select an application to open "casa.sh3d" and other files of type 'Sweet Home 3D'
while on the 2nd install (snap) I see: Select an application to open "casa.sh3d" and other files of type 'Zip archives'
I understand that the type 'Zip archives' comes from the internal format of the file, but this is overridden some part to force type 'Sweet Home 3D'
Where is written that .sh3d is of type 'Sweet Home 3D' and not 'Zip archives'?

[halogen2]

/usr/share/mime/packages/sweethome3d.xml

If you only need the change for one user, you can create a directory ~/.local/share/mime/packages and put this file there. If you need it system-wide it goes in /usr/share/mime/packages .

For the contents of this file to take effect, you'll need to run -

update-mime-database <MIME directory you modified>

where the "MIME directory" is the folder containing the packages folder, e.g. if you put the file in ~/.local/share/mime/packages the MIME directory is ~/.local/share/mime
Refer to man update-mime-database for more info

[mc4man]

I would think the snap has to provide that mime association (it doesn't..
So maybe take the .deb's .xml & put it in youe ~/snap/sweethome3d-homedesign/4/.local/share/mime/packages/ folder and see,
If no good start an issue in snapcraft.io forum

[corradoventu]

copied the .deb's .xml to ~/.local/share/mime/packages and issued command:
corrado@corrado-HP-p5-cc-0731:~$ update-mime-database ~/.local/share/mime
... now it works.
thanks a lot

opened an issue in snapcraft forum: https://forum.snapcraft.io/t/sweetho...hare-mime/6839

[corradoventu]

copied to ~/snap/sweethome3d-homedesign/4/.local/share/mime
but update-mime-database results in:
corrado@corrado-HP-p6-cc-0801:~$ update-mime-database ~/snap/sweethome3d-homedesign/4/.local/share/mime
Note that '/home/corrado/snap/sweethome3d-homedesign/4/.local/share' is not in the search path
set by the XDG_DATA_HOME and XDG_DATA_DIRS
environment variables, so applications may not
be able to find it until you set them. The
directories currently searched are:

- /home/corrado/.local/share
- /usr/share/ubuntu
- /usr/local/share
- /usr/share
- /var/lib/snapd/desktop

corrado@corrado-HP-p6-cc-0801:~$