newbie question #2: plugin-based applications

[Alec Leamas]

On 01/07/18 18:35, John Stebbins wrote:
> On 07/01/2018 09:20 AM, Alec Leamas wrote:
>> Dear list,
>>
>> Yes, I ran into two problems flatpaking opencpn [1]. The other is that
>> opencpn uses a lot of plugins, some of which typically installed in an
>> existing opencpn installation. The question then becomes: how can we
>> accomnplish this in the application sandbox?
>>
>> Can we just drop a pre-built plugin.so in the sandbox? How, then? 

> Yes, it is possible. In flatpak lingo, these are called extensions.
> There are not a lot of examples out there of application plugins,
> but Hexchat is one.  There is also a current PR for VLC to add plugin support.
> 
> Hexchat app where it defines the extension point
> https://github.com/flathub/io.github.Hexchat
> 
> And the Hexchat perl plugin that uses the extension point
> https://github.com/flathub/io.github.Hexchat.Plugin.Perl

Thanks for good pointers! I think I grasp parts of it, but stumble on
the fact that flatpack-builder doesn't support building extensions of
this kind[1].

Has anyone a working example how to build an extension like this i. e.,
something which extends an app rather than a runtime?

Cheers!

--alec

[1] https://github.com/flatpak/flatpak-builder/issues/26