Allows custom Currency Provider through inheritance

crypto-currency-provider.php

@@ -0,0 +1,43 @@
+<?php
+
+use Brick\Money\Exception\UnknownCurrencyException;
+
+require_once __DIR__ . '/vendor/autoload.php';
+
+class CryptoCurrencyProvider implements \Brick\Money\CurrencyProviderInterface
+{
+
+    public function getCurrency(string $currencyCode): \Brick\Money\Currency
+    {
+        $cryptoCurrency = [
+            'BTC' => new \Brick\Money\Currency('BTC', 0, 'Bitcoin', 8 ),
+        ];
+
+        return $cryptoCurrency[$currencyCode] ?? throw UnknownCurrencyException::unknownCurrency($currencyCode);
+    }
+
+    public function getCurrencyForCountry(string $currencyCode): \Brick\Money\Currency
+    {
+        throw new UnknownCurrencyException('Crypto Currency don\'t have a country code.');
+    }
+}
+
+class CryptoCurrency extends \Brick\Money\Currency {
+    protected static function getCurrencyProvider(): \Brick\Money\CurrencyProviderInterface
+    {
+        return new CryptoCurrencyProvider();
+    }
+}
+
+\Brick\Money\Money::of(2, CryptoCurrency::of('BTC'));
+\Brick\Money\Money::of(2, \Brick\Money\Currency::of('EUR'));
+
+class CryptoMoney extends \Brick\Money\Money {
+    protected static function getCurrencyProvider(): \Brick\Money\CurrencyProviderInterface
+    {
+        return new CryptoCurrencyProvider();
+    }
+}
+
+CryptoMoney::of(2, 'BTC')->plus(CryptoMoney::of(2, 'BTC'));
+CryptoMoney::of(2, 'BTC')->plus(\Brick\Money\Money::of(2, \Brick\Money\Currency::of('EUR')));

src/Currency.php

@@ -11,7 +11,7 @@
 /**
  * A currency. This class is immutable.
  */
-final class Currency implements Stringable, JsonSerializable
+class Currency implements Stringable, JsonSerializable
 {
     /**
      * The currency code.
@@ -71,6 +71,11 @@ public function __construct(string $currencyCode, int $numericCode, string $name
         $this->defaultFractionDigits = $defaultFractionDigits;
     }
 
+    protected static function getCurrencyProvider() : CurrencyProviderInterface
+    {
+        return ISOCurrencyProvider::getInstance();
+    }
+
     /**
      * Returns a Currency instance matching the given ISO currency code.
      *
@@ -80,7 +85,7 @@ public function __construct(string $currencyCode, int $numericCode, string $name
      */
     public static function of(string|int $currencyCode) : Currency
     {
-        return ISOCurrencyProvider::getInstance()->getCurrency($currencyCode);
+        return static::getCurrencyProvider()->getCurrency($currencyCode);
     }
 
     /**
@@ -94,7 +99,7 @@ public static function of(string|int $currencyCode) : Currency
      */
     public static function ofCountry(string $countryCode) : Currency
     {
-        return ISOCurrencyProvider::getInstance()->getCurrencyForCountry($countryCode);
+        return static::getCurrencyProvider()->getCurrencyForCountry($countryCode);
     }
 
     /**

src/CurrencyProviderInterface.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Brick\Money;
+
+use Brick\Money\Exception\UnknownCurrencyException;
+
+interface CurrencyProviderInterface
+{
+    /**
+     * @throws UnknownCurrencyException If an unknown currency code is given.
+     */
+    public function getCurrency(string $currencyCode): Currency;
+
+    /**
+     * @throws UnknownCurrencyException If the country code is unknown, or there is no single currency for the country.
+     */
+    public function getCurrencyForCountry(string $currencyCode): Currency;
+}

src/ISOCurrencyProvider.php

@@ -9,7 +9,7 @@
 /**
  * Provides ISO 4217 currencies.
  */
-final class ISOCurrencyProvider
+final class ISOCurrencyProvider implements CurrencyProviderInterface
 {
     private static ?ISOCurrencyProvider $instance = null;
 

src/Money.php

@@ -31,7 +31,7 @@
  * - CustomContext handles monies with a custom scale, and optionally step.
  * - AutoContext automatically adjusts the scale of the money to the minimum required.
  */
-final class Money extends AbstractMoney
+class Money extends AbstractMoney
 {
     /**
      * The amount.
@@ -181,7 +181,7 @@ public static function of(
         RoundingMode $roundingMode = RoundingMode::UNNECESSARY,
     ) : Money {
         if (! $currency instanceof Currency) {
-            $currency = Currency::of($currency);
+            $currency = static::getCurrencyProvider()->getCurrency($currency);
         }
 
         if ($context === null) {
@@ -193,6 +193,11 @@ public static function of(
         return self::create($amount, $currency, $context, $roundingMode);
     }
 
+    protected static function getCurrencyProvider() : CurrencyProviderInterface
+    {
+        return ISOCurrencyProvider::getInstance();
+    }
+
     /**
      * Returns a Money from a number of minor units.
      *
@@ -219,7 +224,7 @@ public static function ofMinor(
         RoundingMode $roundingMode = RoundingMode::UNNECESSARY,
     ) : Money {
         if (! $currency instanceof Currency) {
-            $currency = Currency::of($currency);
+            $currency = static::getCurrencyProvider()->getCurrency($currency);
         }
 
         if ($context === null) {
@@ -245,7 +250,7 @@ public static function ofMinor(
     public static function zero(Currency|string|int $currency, ?Context $context = null) : Money
     {
         if (! $currency instanceof Currency) {
-            $currency = Currency::of($currency);
+            $currency = static::getCurrencyProvider()->getCurrency($currency);
         }
 
         if ($context === null) {
@@ -729,7 +734,7 @@ public function convertedTo(
         RoundingMode $roundingMode = RoundingMode::UNNECESSARY,
     ) : Money {
         if (! $currency instanceof Currency) {
-            $currency = Currency::of($currency);
+            $currency = static::getCurrencyProvider()->getCurrency($currency);
         }
 
         if ($context === null) {
@@ -836,4 +841,4 @@ protected function checkContext(Context $context, string $method) : void
             throw MoneyMismatchException::contextMismatch($method);
         }
     }
-}
+}