2.8 how to use group properties with panel?

is there a tut on how to use group properties and a class panel

or can someone can explain how to use this feature

happy bl

here is sample file with a simple panel and a group of properties
but it is not working

can some one help to make this work

UI-Group-Simple-Panel1.blend (136.2 KB)

happy bl

classes = (
    # You need to add Groupprop1 here so it will be registered and 
    # can then be used, that's missing in your file.

I got an indentation error when I tried to add the properties into the panel but it could be solved using Format > Convert Whitespace > To Tabs. Here’s the working script:

UI-Group-Simple-Panel1.blend1 (137.6 KB)

sorry never use this feature before - group properties
so learning how to here !

I saw 2 other links but much more advance and complicated to understand

I ran your new version
got an error on Tab msg
not certain why !

but also I cannot see the panel in user preference anymore
any idea why it is doing this ?

also after it works how and where can you access the properties
to read write or use in the operator panel for instance

thanks for feeback
happy bl

by the way i’m using 2.80 not the latest 2.81
hope it will also work in 2.81 if no other API changes

happy bl

not certain what happen but I had to re boot my PC and then the addon
works like a charm !

only thing left I guess is how do you read write props in
other parts of the addon
like Main or inside a function or other class?

happy bl