Questions about the Backend Interface

[linas@linas.org]

It's been rumoured that Derek Atkins said:
> > > > 	2) There appears to be no way for the backend to trigger an
> > > >            event to the engine/GUI if something happens.  For example,
> > > >            I'd like the backend (server) to signal to the engine
> > > >            (client) that some information changed, or perhaps even
> > > >            pushing the changed information.
> > 
> > Terminology, as used in gnucash:
> > -- backend: the part of the client that knows how to talk to servers.
> > -- engine: the part of the client that provides a data cache and a 
> >    uniform API to the GUI.
> > 
> > To answer your question: in practice, the backend can 'push' new data 
> > into the engine, because it has access to all the pointers & structures. 
> 
> Hrm.  Then perhaps the best way to 'trigger' an event is to have the
> server push the new data to the backend, and the backend can then push
> it into the engine and notify the engine that the data has changed?

Yes.  Although the last step can be skipped: the backend itself
can trigger the event mechanism to tell the gui that something changed 
(using suspend_events and resume_events in gnc-event.c, I beleive).

--linas