Money Openexchangerates Bank

A gem that calculates the exchange rate using published rates from openexchangerates.org

Openexchangerates API

{
  "timestamp": 1441101909,
  "base": "USD",
  "rates": {
      /* 190 currencies */
      "AUD": 1.413637,
      "CAD": 1.316495,
      "CHF": 0.96355,
      "EUR": 0.888466,
      "BTC": 0.004322, /* Includes cryptocurrencies! */
      ...
      }
}

See more about Openexchangerates product plans on https://openexchangerates.org/signup.

Features

• supports over 200 currencies
• includes cryptocurrencies
• precision of rates up to 6 digits after point
• uses fast and reliable json api
• average response time < 20ms
• supports caching currency rates
• calculates every pair rate calculating inverse rate or using base currency rate
• supports multiple server instances, thread safe

Installation

Add this line to your application's Gemfile:

gem 'money-openexchangerates-bank'

And then execute:

$ bundle

Or install it yourself as:

$ gem install money-openexchangerates-bank

Usage

# Minimal requirements.
require 'money/bank/openexchangerates_bank'
moxb = Money::Bank::OpenexchangeratesBank.new
moxb.access_key = 'your access_key from https://openexchangerates.com/signup'

# (optional)
# Set the base currency for all rates. By default, USD is used.
# OpenexchangeratesBank only allows USD as base currency for the free plan users.
moxb.source = 'EUR'

# (optional)
# Set the seconds after than the current rates are automatically expired.
# By default, they never expire, in this example 1 day.
moxb.ttl_in_seconds = 86400

# (optional)
# Use https to fetch rates from OpenexchangeratesBank.
# OpenexchangeratesBank only allows http as connection for the free plan users.
moxb.secure_connection = true

# Define cache (string or pathname).
moxb.cache = 'path/to/file/cache'

# Update rates (get new rates from remote if expired or access rates from cache).
# Be sure to define the cache first before updating the rates.
moxb.update_rates

# Force update rates from remote and store in cache.
# Be sure to define the cache first before updating the rates.
# moxb.update_rates(true)

# Set money rounding mode.
Money.rounding_mode = BigDecimal::ROUND_HALF_EVEN

# Set money default bank to Openexchangerates bank.
Money.default_bank = moxb

More methods

moxb = Money::Bank::OpenexchangeratesBank.new

# Returns the base currency set for all rates.
moxb.source

# Include also alternative rates.
moxb.alternatives = :all

# Get only alternative rates.
moxb.alternatives = :only

# Default is nil to get only regular rates.
# moxb.alternatives = nil

# Expires rates if the expiration time is reached.
moxb.expire_rates!

# Returns true if the expiration time is reached.
moxb.expired?

# Get the API source url.
moxb.source_url

# Get the rates timestamp of the last API request.
moxb.rates_timestamp

# Get the rates timestamp of loaded rates in memory.
moxb.rates_mem_timestamp

How to exchange

# Exchange 1000 cents (10.0 USD) to EUR
Money.new(1000, 'USD').exchange_to('EUR')        # => #<Money fractional:89 currency:EUR>
Money.new(1000, 'USD').exchange_to('EUR').to_f   # => 8.9

# Format
Money.new(1000, 'USD').exchange_to('EUR').format # => €8.90

# Get the rate
Money.default_bank.get_rate('USD', 'CAD')        # => 0.9

See more on https://github.com/RubyMoney/money.

Using gem money-rails

You can also use it in Rails with the gem money-rails.

require 'money/bank/openexchangerates_bank'

MoneyRails.configure do |config|
  moxb = Money::Bank::OpenexchangeratesBank.new
  moxb.access_key = 'your access_key from https://openexchangerates.com/signup'
  moxb.update_rates

  config.default_bank = moxb
end

Cache

You can also provide a Proc as a cache to provide your own caching mechanism perhaps with Redis or just a thread safe Hash (global). For example:

moxb.cache = Proc.new do |v|
  key = 'money:openexchangerates_bank'
  if v
    Thread.current[key] = v
  else
    Thread.current[key]
  end
end

Process

The gem fetches all rates in a cache with USD as base currency. It's possible to compute the rate between any of the currencies by calculating a pair rate using base USD rate.

Tests

You can place your own key on a file or environment variable named TEST_ACCESS_KEY and then run:

bundle exec rake

Refs

• Gem money
• Gem money-currencylayer-bank
• Gem money-open-exchange-rates
• Gem money-historical-bank

Other Implementations

• Gem money-currencylayer-bank
• Gem money-open-exchange-rates
• Gem money-historical-bank
• Gem currencylayer
• Gem eu_central_bank
• Gem nordea
• Gem google_currency

Contributors

• See github.com/phlegx/money-openexchangerates-bank.
• Inspired by github.com/phlegx/money-currencylayer-bank.

Contributing

1. Fork it ( https://github.com/[your-username]/money-openexchangerates-bank/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

License

The MIT License

Copyright (c) 2022 Phlegx Systems Technologies GmbH