aqbanking5 support of gnucash

[Christian Stimming]

Am Thursday 12 August 2010 schrieb Martin Preuss:
> > The normal online banking usage still works, as the aqbanking4-style
> >  GWEN_GUI implementation of gnucash still seems to be sufficient for
> >  those operations. But the setup doesn't work. 
> 
> [...]
> 
> Thats correct. The old callbacks GnuCash implemented are still present and
> are still used for GUI implementations not supporting the dialog
> framework.
> 
> However, it should be fairly easy to adapt to the Gtk2Gui provided by gwen:
> - create the Gtk2Gui object
> ...

Thanks, Martin, for the explanation and the detailed advice on how this should 
be implemented in gnucash. Unfortunately there is a small source code 
organization problem here, which is why I'm hesitating to spending time on 
this. I'll explain it in detail because for me this is the reason why I didn't 
start with this for quite some time by now:

The gnucash code in src/import-export/aqbanking/ currently compiles and works 
fine with aqbanking4. Implementing the changes you described for aqbanking5 
will clearly make the code of that directory incompatible with aqbanking4. I'm 
afraid one has to add too many #ifdef USING_AQBANKING5 (a convenience macro we 
would define in import-export/aqbanking/gnc-ab-utils.h) conditionals, which 
always look quite ugly. The only other source code organization possibility 
would be to copy the import-export/aqbanking directory to a new second import-
export/aqbanking5 directory, where we could remove all the aqbanking4 stuff 
and write solely for aqbanking5. But that would duplicate a lot of code as 
well.

Hm... While writing this, it occurred to me the copying to import-
export/aqbanking5 might indeed be the better way in the long run. That 
solution would be the only one that ensures the old aqbanking4 code will 
continue to work as expected. So that's probably what I would recommend for 
anyone who wants to implement correct support of aqbanking5 in gnucash. And, 
as Martin explained, in that new directory one can benefit from all the GUI-
handling simplifications which are now implemented by Martin in aqbanking5.

This should just give the correct picture for anyone who wants to deal with 
that task. After all, the task might be solved within 2-3 days of work... 
volunteers, anyone?

Regards,

Christian