Class: Money::Bank::OANDA

Inherits:
VariableExchange
  • Object
show all
Defined in:
lib/oanda_bank.rb

Defined Under Namespace

Classes: FetchError

Constant Summary collapse

INSTRUMENTS_URL = 
"https://api-fxtrade.oanda.com/v1/instruments"
RATES_URL = 
"https://api-fxtrade.oanda.com/v1/prices"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(account_id, access_token, opts = {}) ⇒ OANDA

Returns a new instance of OANDA.



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# File 'lib/oanda_bank.rb', line 23

def initialize(, access_token, opts={})
  @client = OAuth2::Client.new(nil, nil)
  @access_token = OAuth2::AccessToken.new(@client, access_token)
  @account_id = 
  @updating_mutex = Mutex.new
  setup
end

Instance Attribute Details

#rates_expiration ⇒ Time (readonly)

Returns the time when the rates expire.

Returns:

  • (Time) —

    Returns the time when the rates expire.



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# File 'lib/oanda_bank.rb', line 21

def rates_expiration
  @rates_expiration
end

#ttl_in_seconds ⇒ Integer

Returns the Time To Live (TTL) in seconds.

Returns:

  • (Integer) —

    Returns the Time To Live (TTL) in seconds.



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# File 'lib/oanda_bank.rb', line 18

def ttl_in_seconds
  @ttl_in_seconds
end

Instance Method Details

#expire_rates ⇒ Object 



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# File 'lib/oanda_bank.rb', line 66

def expire_rates
  if @ttl_in_seconds && @rates_expiration <= Time.now
    if @updating_mutex.try_lock
      begin
        update_rates!
        true
      ensure
        @updating_mutex.unlock
      end
    end
  else
    false
  end
end

#get_rate(from, to, opts = {}) ⇒ Object 



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# File 'lib/oanda_bank.rb', line 43

def get_rate(from, to, opts = {})
  expire_rates
  fn = Proc.new do
    straight_through = @rates[rate_key_for(from, to)]
    if straight_through
      straight_through
    else
      to_usd   = @rates[rate_key_for(from, 'USD')]
      from_usd = @rates[rate_key_for('USD', to)]
      if (to_usd && from_usd)
        to_usd * from_usd
      else
        nil
      end
    end
  end
  if opts[:without_mutex]
    fn.call
  else
    @mutex.synchronize { fn.call }
  end
end

#update_rates! ⇒ Object 



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# File 'lib/oanda_bank.rb', line 31

def update_rates!
  begin
    new_rates = fetch_rates
    @mutex.synchronize do
      @rates = new_rates
      refresh_rates_expiration!
    end
  rescue StandardError => e
    raise FetchError.new(e.message)
  end
end