miniGL multi-currency support

/by apr/ As a follow-up to the recent post about miniGL layers we have removed support for foreign amounts at the transaction.entry level, foreign currencies are now handled in their own layer. That means that if you have a checking account and a savings account (we usually figure out the account type based on the content of the processing code field) in multiple currencies, you don´t need a separate set of accounts (one per type), the same account can hold transactions in multiple currencies. As mentioned in the previous post, we use layers to deal with pending versus real transactions (think pre-auth/completion) and we found an easy way to add multi-currency support by defining a PENDING_OFFSET constant. We are still working in the layers plan for our jCard system, but as an initial take, we have defined the PENDING_OFFSET=1000 and we store transactions in their corresponding layer using the iso4217 currency code, so e.g.: we store real dollars in 840 and pending dollars in 1840 (same goes for other currencies). So far the new setup looks extremely simple and straightforward. A close friend and CPA has contributed a very nice idea to the mix, conversion layers. I´m still not sure if we want to handle them with the existing database schema or we want some supporting tables for that, it has been good food for thought for now.