GnuCash for Symbian

[Hendrik Boom]

On Wed, 04 Apr 2012 15:24:47 +0200, Łukasz Spas wrote:

> Hello.
> 
> I've developed small application for Symbian (tested on S60) which
> allows users to manage their finances using their Symbian phone. (Here
> is the repo: https://gitorious.org/gnucash-s60/gnucash-s60)
>   It is still incomplete because I would like to add functionality which
> allows to synchronize list of transactions with desktop' GnuCash via
> Bluetooth using QIF file format.
> And here goes the question - is it hard to add "reciving QIF file via
> Bluetooth & importing it to GnuCash's database" functionality? I have
> never look inside GnuCash's code and I don't know where I could start.
> (Maybe someone could help?) Moreover, is it even possible to add such
> Bluetooth import functionality to main GnuCash repo? I think it might be
> useful for many of smart-phones owners and gives a possibility to write
> many of mobile ports/clients of GnuCash easily.

Doing bluetooth is probably the easy part.  It's just a comm protocol, 
after all.

The trouble lies with QIF.  At least the last time I looked, it just 
doesn't have all the information you need.  It doesn't identify the 
account the QIF file is about, and it doesn't clearly identify the 
accounts that are at the other end of transactions.  The result is that 
the QIF reader in gnucash contains *lots* of code about guessing what 
accounts are to be used for different transactions and recording user 
feedback about the guesses to make better ones in the future.  Not to 
mention that if you get another QIF from the bank a week later, it has to 
identify which transactions are *already* in the gnucash file and which 
are new.  QIF provides no transaction serial numbers to make this 
reliable.  Such serial  numbers are de rigeur in any professionally 
designed protocol.

In any case, if the user has edited the transaction using gnucash, you 
*don't* want that change to make the importer fail to recognize it and 
import it anew.

So, to do the job *right* (whether it's worth the effort or not), gnucash 
would have to have unique transaction IDs for each transaction in its 
database. (Does it already do this?  I don't know.)

Then you could perhaps look at the code for qif import (or maybe there's 
another importer you could look at which might be better) and adapt it to 
whatever intermediate file format you'd *like* to use with your 
application.  That file format should explicitly identify the accounts at 
both ends of each transaction.  Gnucash accounts, at least in the XML 
file, have some king of binary hash ID to identify them uniquely.  That 
might be useful here.  I don't know if those hashes are in the actual 
data base, though, or just part of the XML file format.  You app would of 
course have to know the names of the accounts so that the user with the 
mobile phone could select them unambiguously.

It might even be possible that gnucash's XML format for transactions 
might have the right information for your intermediate files.  Or not. 

All in all, it's a big job, and *I* didn't volunteer to do anything like 
it a few years ago when I thought it might be useful.

-- hendrik