Money Currencylayer Bank

A gem that calculates the exchange rate using published rates from currencylayer.com

Currencylayer API

{
  "timestamp": 1441101909,
  "source": "USD",
  "quotes": {
      /* 168 currencies */
      "USDAUD": 1.413637,
      "USDCAD": 1.316495,
      "USDCHF": 0.96355,
      "USDEUR": 0.888466,
      "USDBTC": 0.004322, /* Includes Bitcoin currency! */
      ...
      }
}

See more about Currencylayer product plans on https://currencylayer.com/product.

Features

supports 168 currencies
includes Bitcoin virtual currency
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-currencylayer-bank'

And then execute:

$ bundle

Or install it yourself as:

$ gem install money-currencylayer-bank

Usage

# Minimal requirements.
require 'money/bank/currencylayer_bank'
mclb = Money::Bank::CurrencylayerBank.new

# New endpoint: https://apilayer.com/marketplace/currency_data-api or
# old endpoint: https://currencylayer.com/product
mclb.access_key = 'your access_key'

# (optional)
# Use the old endpoint api.currencylayer.com. By default, the new endpoint is used.
mclb.currencylayer = true

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

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

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

# (optional)
# Rescue with rates from the cache instead of reporting an error when the endpoint fails.
mclb.rescue_with_cache = true

# Define cache (string or pathname).
mclb.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.
mclb.update_rates

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

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

# Set money default bank to Currencylayer bank.
Money.default_bank = mclb

More methods

mclb = Money::Bank::CurrencylayerBank.new

# Returns true if configured to use the old endpoint.
mclb.currencylayer

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

# Returns true if configured to rescue rates from the cache.
mclb.rescue_with_cache

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

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

# Get the API source url.
mclb.source_url

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

# Get the rates timestamp of loaded rates in memory.
mclb.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/currencylayer_bank'

MoneyRails.configure do |config|
  mclb = Money::Bank::CurrencylayerBank.new
  mclb.access_key = 'your access_key from https://currencylayer.com/product'
  mclb.update_rates

  config.default_bank = mclb
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:

mclb.cache = Proc.new do |v|
  key = 'money:currencylayer_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

Other Implementations

Contributors

See github.com/phlegx/money-currencylayer-bank.
Inspired by github.com/spk/money-open-exchange-rates.

Contributing

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

License

The MIT License