Currency Rate Update

This module adds a new screen under Accounting called Currency Rates Providers. There you create a provider, choose the service (European Central Bank is available), pick the currencies to update, and set how often rates should be refreshed (every N days, weeks or months). A button on the provider form, "Update Rates Now", opens a small wizard where you choose a start date, an end date and the providers, then press Update to fetch rates immediately.

A daily scheduled job runs in the background. It only processes providers that are active and whose company has the "Automatic Currency Rates (OCA)" option enabled; that option is set per company in Accounting settings. For daily providers it fetches all missing days, otherwise it fetches only the newest rate. Each provider shows its last successful update and next scheduled update, and failures are posted as messages on the provider so you can see what went wrong.

Rates are written into the standard currency rates, and each rate records which provider produced it. If someone edits a rate or its date by hand, the link to the provider is cleared automatically. The module also warns you when the European Central Bank service is used with a company currency other than EUR, because rates are then recalculated and may differ from real market rates.