cpp branch

[Geert Janssens]

Op dinsdag 10 januari 2017 15:38:27 CET schreef Robert Fewell:
> Geert,
> 
> Thank you for the comments, especially the date ones which now make sense.
> I will have a look at my changes and why I made them as it may relate to
> changes I will need to the price importer.
> 
You're welcome :)

I have just pushed the most recent state of my cpp branch (minus a final work 
in progress) to my github repository. You may want to rebase to that one. It 
should present a more or less usable csv transaction import assistant.

Note I don't expect you to take the whole transaction related code for your 
price importer. You may follow the design obviously if it suits you as well. 
But I think there are a number of useful classes in there which you probably 
can reuse as they are. I'm thinking about the gnc-tokenizer class and its 
subclasses for csv separated or fixed width column data. They should allow you 
to split your csv file in a table of values to be interpreted by a price 
specific parser. For transaction importing this specific parser is implemented 
in the GncTxImport class (note the absence of "csv" in that name - I believe 
the class is generic enough to also handle transactions coming from qif or ofx 
data in the future by adding specialized tokenizers for these formats).

The design principles in my csv importer are as follows:
- the assistant code is "dumb". It's responsible for displaying data and 
passing user commands to the real parser. So it shouldn't make any decisions 
other than what's needed to properly display all the information (including 
enabling/disabling options and buttons)
- the real intelligence is stored in the GncTxImport class, which is 
responsible for everything related to the data. It will massage the data found 
in the input file into proper gnucash transactions. This class is completely 
gui-less, so it could potentially even be used from non-gui interactions, such 
as our python bindings (if someone would add the currently still missing 
bindings).
- Some parts are delegated to helper classes. One such example is the 
tokenizer class which handles everything from loading a file to splitting the 
data into a table of strings. From there GncTxImport takes over. The settings 
are also stored in a separate class to simplify loading and saving user 
presets and switching between them. This is heavily based on your initial work 
to load and save these presets, mostly reworked into a c++ class and 
redesigned a bit to make it a more central piece of the GncTxImport class.

I hope this information will help you better understand the new csv importer 
and at the same time help you to model your own price importer, which can 
probably be implemented less generically. I would keep the strict separation 
of gui and business logic though. Make your price importer class such that it 
can be used without a gui and let the gui interact with it by querying the 
information it needs/passing the inputs it receives from the user.

Regards,

Geert