ISOCurrencies.php

<?php
 
namespace Money\Currencies;
 
use Money\Currencies;
use Money\Currency;
use Money\Exception\UnknownCurrencyException;
 
final class ISOCurrencies implements Currencies
{
    private static $currencies;
 
    public function contains(Currency $currency)
    {
        return isset($this->getCurrencies()[$currency->getCode()]);
    }
 
    public function subunitFor(Currency $currency)
    {
        if (!$this->contains($currency)) {
            throw new UnknownCurrencyException('Cannot find ISO currency '.$currency->getCode());
        }
 
        return $this->getCurrencies()[$currency->getCode()]['minorUnit'];
    }
 
    public function numericCodeFor(Currency $currency)
    {
        if (!$this->contains($currency)) {
            throw new UnknownCurrencyException('Cannot find ISO currency '.$currency->getCode());
        }
 
        return $this->getCurrencies()[$currency->getCode()]['numericCode'];
    }
 
    public function getIterator()
    {
        return new \ArrayIterator(
            array_map(
                function ($code) {
                    return new Currency($code);
                },
                array_keys($this->getCurrencies())
            )
        );
    }
 
    private function getCurrencies()
    {
        if (null === self::$currencies) {
            self::$currencies = $this->loadCurrencies();
        }
 
        return self::$currencies;
    }
 
    private function loadCurrencies()
    {
        $file = __DIR__.'/../../resources/currency.php';
 
        if (file_exists($file)) {
            return require $file;
        }
 
        throw new \RuntimeException('Failed to load currency ISO codes.');
    }
}