Simple API client to fetch exchange rate to PLN for selected currency and date from http://api.nbp.pl

Add this line to your application's Gemfile:

gem 'nbppl'

And then execute:

$ bundle

Or install it yourself as:

$ gem install nbppl

# fetch mid rate for specific currency and date
Nbppl::Client.new.fetch_mid_rate("EUR", Date.parse("2021-06-01"))

# fetch mid rate from closest date in the past
Nbppl::Client.new.closest_mid_rate("USD", Date.parse("2021-06-06"))
=> [3.6931, #<Date: 2021-06-04 ((2459370j,0s,0n),+0s,2299161j)>]

# use caching by making multiple calls with same class instance
client = Nbppl::Client.new
client.fetch_mid_rate(a)
client.fetch_mid_rate(a) # no unnecessary api call
# or by using Nbppl::Client.current
Nbppl::Client.current.fetch_mid_rate(a)
Nbppl::Client.current.fetch_mid_rate(a) # no unnecessary api call

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/meceo/nbppl.

The gem is available as open source under the terms of the MIT License.