automatic ex/import of data

[Linas Vepstas]

On Fri, Jun 18, 2004 at 05:25:01PM +0200, Christian Stimming was heard to remark:
> Hello Tomas,
> 
> Tomas Pospisek's Mailing Lists schrieb:
> >1. do there exist hooks where a script or external application can be
> >   called when a transaction is entered?
> >2. is there a possiblity to call gnucash through some kind of RPC, from
> >   the command line or as a daemon to add a transaction?
> 
> I thought at least for your described question #2 the "--evaluate" 
> command line option of gnucash would be of some help. I.e. your 
> cybercash frontend could come up with some scheme statements that would 
> actually create a transaction and add it to the appropriate places -- at 
> least that's what I would expect...

One of the goals of scheme-ifying gnucash was to allow exactly #2, and
even make it easy.  The idea was that you'd write a little scheme
script that did whatever you wanted, and pushed the data into/out-of
gnucash.   But nobody or almost nobody does/did that, so we have 
little track record for this.  FYI, the earlier incarnation used
perl for this; the current perl-based price lookup is a vestige of that.
Almost no one used the perl bindings either.

Anyway, I have no idea if we suceeded or failed with the scheme
bindings.  Failed, I suppose, in that no one uses them or cares very
much ... 

> As for the question #1, no, there is nothing available at the moment. 

Actually, there is something, sort-of.

There are C-language 'gnc events' generated whenever a transaction is 
created/modified/destoyed.  These events are used to tell the GUI
when to update.  I am not sure if there are scheme wrappers for these
events or not.  If there are scheme wrappers, then that's your script
hook.

Note that I am planning on changing the C-language api to these events, 
to make them richer and more powerful.  I'll try to maintain some amount
of backwards compat, but am not sure right now.

--linas

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