[Gnumed-devel] Re: problem with UI/logic separation

[Hilmar Berger]

Karsten Hilbert schrieb:

> Why is it undesirable to split into __init__ and
> initiate_encounter ?  Because it would be desirable to not
> require the programmers to think about whether they need to
> call initiate_encounter() after getting a handle on a patient
> chart object. 
>
> Due to the fact that we use lazy instantiation of the EMR
> object (upon first access to it via the patient object) any
> access can be the one needing to initialize an encounter.
> Hence any access would need to be followed by
> initiate_encounter(). 
So you have a situation where GUI-level code calls non-Gui-level code 
which can fail and you don't want to communicate the error back to the 
calling GUI-level code but instead keep all error-handling logic in the 
non-GUI code. Still you want to have some GUI-interaction to resolve the 
 error. That's what I call a lot of magic :).
So we need some way to call GUI code from non-Gui code without returning 
to the calling GUI code first, right ?
Does that work if the non-Gui code is in the same thread as the calling 
Gui-Code ?
You could have a sleeping GUI-thread that waits for messages from 
non-GUI code to show some question and return the answer (via 
gmDispatcher).
Or you could define a critical point in your Gui-Non-Gui interaction 
where __init__ is called and the presence of the encounter checked 
explicitely. Then the GUI could handle the error once for all.
Well, I don't know if this ideas make sense...

Hilmar