Exchanges::Rates::Nbp

Simple gem that gets exchange rates from the Polish National Bank.

Installation

Add this line to your application's Gemfile:

    gem 'exchanges-rates-nbp'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install exchanges-rates-nbp

Usage

Basic usage:

        nbp = Exchanges::Nbp.new(nil, nil)

parameters:

date - default Date.today, you can pass another valid date
args - optional parameters, currently only one selected_currencies, example below

Class instance has three important methods

codes - returns currency symbols from table,
published_at - returns publication date exchange rates,
rates(currency) - returns currency rate at indicated date

To get all codes from table call it:

        nbp.codes #=> ["THB", "USD", "AUD", "HKD", "CAD", "NZD", "SGD", "EUR", "HUF", "CHF", "GBP", "UAH", "JPY", "CZK", "DKK", "ISK", "NOK", "SEK", "HRK", "RON", "BGN", "TRY", "LTL", "ILS", "CLP", "PHP", "MXN", "ZAR", "BRL", "MYR", "RUB", "IDR", "INR", "KRW", "CNY", "XDR"]

To get exchange rate e.g. USD you have to call:

        nbp.rates("USD") #=> {:symbol=>"USD", :name=>"dolar amerykański", :base=>1.0, :average_rate=>3.2964}

If you interested only selected currencies at indicated day use in this way:

        nbp = Exchanges::Nbp.new(Date.today - 3, {selected_currencies: ['USD', 'EUR']})

Now you can retrieve currency rates for chosen:

    nbp.codes.each do |c|
      nbp.rates(c)
    end

Future ideas

Currency and CurrencyRate model, Sequel/ActiveRecord migration
Background job to retrieve currency rates automatically

Contributing