Skip to content

Exchange

Everyone’s tasks are different and with the help of this functionality you can add exchange rates to your wallets.

The wallet currency is set via meta. Example:

php
$user->createWallet([
    'name' => 'My USD Wallet',
    'meta' => ['currency' => 'USD'],
]);

Service for working with currencies you need to write yourself or use library.

Service for working with currency

We will write a simple service. We will take the data from the array, and not from the database.

php
use Bavix\Wallet\Internal\Service\MathServiceInterface;
use Bavix\Wallet\Services\ExchangeServiceInterface;

class MyExchangeService implements ExchangeServiceInterface
{
    private array $rates = [
        'USD' => [
            'RUB' => 67.61,
        ],
    ];

    private MathServiceInterface $mathService;

    public function __construct(MathServiceInterface $mathService)
    {
        $this->mathService = $mathService;

        foreach ($this->rates as $from => $rates) {
            foreach ($rates as $to => $rate) {
                if (empty($this->rates[$to][$from])) {
                    $this->rates[$to][$from] = $this->mathService->div(1, $rate);
                }
            }
        }
    }

    /** @param float|int|string $amount */
    public function convertTo(string $fromCurrency, string $toCurrency, $amount): string
    {
        return $this->mathService->mul($amount, $this->rates[$fromCurrency][$toCurrency] ?? 1);
    }
}

Service Registration

The service you wrote must be registered, this is done in the file config/wallet.php.

php
return [
    // ...
    'services' => [
        'exchange' => MyExchangeService::class,
        // ...
    ],
    // ...
];

Exchange process

Create two wallets.

php
$usd = $user->createWallet([
    'name' => 'My Dollars',
    'meta' => ['currency' => 'USD'],
]);

$rub = $user->createWallet([
    'name' => 'My Ruble',
    'meta' => ['currency' => 'RUB'],
]);

We replenish the ruble wallet with 100 rubles.

php
$rub->deposit(10000);

We will exchange rubles into dollars.

php
$transfer = $rub->exchange($usd, 10000);
$rub->balance; // 0
$usd->balance; // 147, это $1.47

Unfortunately, the world is not perfect. You will not get back your 100 rubles.

php
$transfer = $usd->exchange($rub, $usd->balance);
$usd->balance; // 0
$rub->balance; // 9938

Due to conversion and mathematical rounding, you lost 62 kopecks. You have 99 rubles 38 kopecks left.


It's simple!