FAFX

FAFX fetches data from the 90 day European Central Bank (ECB) feed and offers a simple CLI and API to interect with.

Installation

$ gem install fafx

CLI

$ fafx

Usage: fafx [options]
        --recent      Lists most recent rates
        --currencies  Lists available currencies
        --dates       Lists available dates
        --update      Fetches new data from the web

Example of client usage

require 'Date'
require 'fafx'

Fafx::ExchangeRate.at(Date.today, 'GBP', 'USD')
# => 1.2951645399597045

Fafx::ExchangeRate.currencies_available
# => ["USD", "JPY", "BGN", "CZK", ...]

Fafx::ExchangeRate.dates_available
# => ["2018-09-10", "2018-09-07", "2018-09-06", "2018-09-05", ...]

Fafx::ExchangeRate.most_recent
# => {"USD"=>1.1571, "JPY"=>128.54, "BGN"=>1.9558, "CZK"=>25.648, ...}

The at function may raise a DateError or CurrencyError exception, should the date or currency be unavailable.

Updating the exchange rates data

You can update the exchange rates values either via the CLI, Rake task or programmatically:

$ fafx --update

$ rake update_data

require 'fafx'

Fafx::ExchangeRate.update_data

---

One can also schedule a cron job (the following example fetches the data every minute):

* * * * * . ~/.zshrc; fafx -u

Note: . ~/.zshrc is used to load the environment with the Ruby gems path, because cron uses PATH=/usr/bin:/usr/sbin and SHELL=/usr/bin/sh by default. Fonts: here and here