Money TransferWise Bank

A gem that calculates the exchange rate using available rates from the TransferWise Exchange Rate API.

TransferWise API

<s>~ json [ /* 157 currencies */ { “rate”: 1.74145, “source”: “USD”, “target”: “BGN”, “time”: “2019-06-05T17:48:33+0000” }, { “rate”: 1180.34, “source”: “USD”, “target”: “KRW”, “time”: “2019-06-05T17:48:33+0000” }, … ] </s>~

Note that the TransferWise API is only available if you sign up for a free TransferWise account. See more information about their API in the TransferWise API Documentation

Features

Installation

Add this line to your application's Gemfile:

gem 'money-transferwise-bank'

And then execute:

$ bundle

Or install it yourself as:

$ gem install money-transferwise-bank

Usage

~~~ ruby

Minimal requirements

require 'money/bank/transferwise_bank' mtwb = Money::Bank::TransferwiseBank.new mtwb.access_key = 'your access_key from transferwise.com'

Update rates (get new rates from remote if expired or access rates from cache)

mtwb.update_rates

Force update rates from remote and store in cache

mtwb.update_rates(true)

(optional)

Set the base currency for all rates. By default, USD is used.

mtwb.source = 'EUR'

(optional)

Set the seconds after than the current rates are automatically expired

by default, they never expire, in this example 1 day.

mtwb.ttl_in_seconds = 86400

(optional)

Option to use the Sandbox version of the TransferWise API.

By default, this is false and the live API is used.

mtwb.use_sandbox = true

(optional)

Option to raise an error on failure to connect to the API or parse

the response. By default, this is true, but the ability to disable

it is useful when developing without an active internet connection.

mtwb.raise_on_failure = false

Define cache (string or pathname)

mtwb.cache = 'path/to/file/cache'

Set money default bank to transferwise bank

Money.default_bank = mtwb ~~~

More methods

~~~ ruby mtwb = Money::Bank::TransferwiseBank.new

Returns the base currency set for all rates.

mtwb.source

Expires rates if the expiration time is reached.

mtwb.expire_rates!

Returns true if the expiration time is reached.

mtwb.expired?

Get the API source url.

mtwb.source_url

Get the rates timestamp of the last API request.

mtwb.rates_timestamp

Get the rates timestamp of loaded rates in memory.

moxb.rates_mem_timestamp ~~~

How to exchange

~~~ ruby

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 github.com/RubyMoney/money.

Using gem money-rails

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

~~~ ruby require 'money/bank/transferwise_bank'

MoneyRails.configure do |config| mtwb = Money::Bank::TransferwiseBank.new mtwb.access_key = 'your access_key from transferwise.com/product' mtwb.update_rates

config.default_bank = mtwb 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:

<s>~ ruby mtwb.cache = Proc.new do |v| key = 'money:transferwise_bank' if v Thread.current = v else Thread.current end end </s>~

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:

<s>~ bundle exec rake </s>~

Refs

Other Implementations

Contributors

Contributing

  1. Fork it ( github.com/[your-username]/money-transferwise-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 © 2019 Mikel Kew