Class: Money::RatesProvider::OpenExchangeRates

Inherits:
Object
  • Object
show all
Includes:
HTTParty
Defined in:
lib/money/rates_provider/open_exchange_rates.rb

Overview

Retrieves exchange rates from OpenExchangeRates.org API, relative to the given base_currency. It is fetching rates for all currencies in one request, as we are charged on a “per date” basis. I.e. one month’s data for all currencies counts as 30 calls.

Defined Under Namespace

Modules: AccountType

Constant Summary collapse

MIN_DATE =

minimum date that OER has data (docs.openexchangerates.org/docs/historical-json)

Date.new(1999, 1, 1).freeze

Instance Method Summary collapse

Constructor Details

#initialize(oer_app_id, base_currency, timeout, oer_account_type) ⇒ OpenExchangeRates

Parameters

  • oer_app_id - App ID for the OpenExchangeRates API access

  • base_currency - The base currency that will be used for the OER requests. It should be a Money::Currency object.

  • timeout - The timeout in seconds to set on the requests

  • oer_account_type - The OpenExchangeRates account type. Should be one of AccountType::FREE, DEVELOPER, ENTERPRISE, or UNLIMITED



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# File 'lib/money/rates_provider/open_exchange_rates.rb', line 51

def initialize(oer_app_id, base_currency, timeout, )
  @oer_app_id = oer_app_id
  @base_currency_code = base_currency.iso_code
  @timeout = timeout
  @fetch_rates_method_name = if  == AccountType::FREE ||  == AccountType::DEVELOPER
    :fetch_historical_rates
  else
    :fetch_time_series_rates
  end
end

Instance Method Details

#fetch_rates(date) ⇒ Object

Fetches the rates for all available quote currencies (for given date or for a whole month, depending on openexchangerates.org account type). Fetching for all currencies or just one has the same API charge.

It returns a Hash with the rates for each quote currency and date as shown in the example. Rates are BigDecimal.

Parameters

Errors

  • Raises ArgumentError when date is less than January 1st 1999, or greater than yesterday (UTC)

  • Raises Money::RatesProvider::RequestFailed when the OER request fails

Examples

oer.fetch_rates(Date.new(2016, 10, 5))
If Free or Developer account in openexchangerates.org, it will return only for the given date
# => {"AED"=>{"2016-10-05"=>#<BigDecimal:7fa19a188e98,'0.3672682E1',18(36)>}, {"AFN"=>{"2016-10-05"=>#<BigDecimal:7fa19a188e98,'0.3672682E1',18(36)>}, ...
If Enterprise or Unlimited account, it will return for the entire month for the given date 
# => {"AED"=>{"2016-10-01"=>#<BigDecimal:7fa19a188e98,'0.3672682E1',18(36)>, "2016-10-02"=>#<BigDecimal:7fa19b11a5c8,'0.367296E1',18(36)>, ...



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# File 'lib/money/rates_provider/open_exchange_rates.rb', line 85

def fetch_rates(date)
  if date < MIN_DATE || date > max_date
    raise ArgumentError, "Provided date #{date} for OER query should be "\
                         "between #{MIN_DATE} and #{max_date}"
  end

  response = send(@fetch_rates_method_name, date)


  result = Hash.new { |hash, key| hash[key] = {} }

  # sample response can be found in spec/fixtures.
  # we're transforming the response from Hash[iso_date][iso_currency] to
  # Hash[iso_currency][iso_date], as it will allow more efficient caching/retrieving
  response['rates'].each do |iso_date, day_rates|
    day_rates.each do |iso_currency, rate|
      result[iso_currency][iso_date] = rate.to_d
    end
  end

  result
end