CurrencyConversion

Convert Money Amounts between currencies. This library uses an OTP worker to save current conversion rates.

Installation

The package can be installed by adding currency_conversion to your list of dependencies in mix.exs:

def deps do
  [{:currency_conversion, "~> 0.3.1"}]
end

Configuration

• source - Configure which Data Source Should Be Used.
  • Type: atom
  • Default: CurrencyConversion.Source.Fixer
  • Restrictions: Must implement CurrencyConversion.Source behaviour
  • Given Implementations:
    • CurrencyConversion.Source.Fixer - Fixer IO
    • CurrencyConversion.Source.Test - Test Source
• refresh_interval - Configure how often the data should be refreshed. (in ms)
  • Type: integer
  • Default: 86_400_000 (Once per Day)
• test_rates - Configure rates for CurrencyConversion.Source.Test source
  • Type: {atom, %{atom: float}}
  • Default: see CurrencyConversion.Source.Test.@default_rates
  • Example: {:EUR, %{CHF: 7}}

config :currency_conversion,
  source: CurrencyConversion.Source.Fixer,
  source_api_key: "FIXER_ACCESS_KEY",
  # defaults to http since free access key only supports http
  source_protocol: "https",
  refresh_interval: 86_400_000

Custom Source

A custom source can be implemented by using the behaviour CurrencyConversion.Source and reconfiguring the source config.

It only has to implement the function load/0, which produces a struct of type %CurrencyConversion.Rates{}.

Test

To prevent HTTP calls in the Tests, configure the Test Source. (See the configuration test_rates for custom test rates.)

config :currency_conversion,
  source: CurrencyConversion.Source.Test,
  refresh_interval: 86_400_000

Usage

Only the function CurrencyConversion.convert/3 is exposed to the user. The library money is used to represent money amounts.

Example

iex> CurrencyConversion.convert(Money.new(7_00, :CHF), :USD)
%Money{amount: 10_50, currency: :USD}