PHP SDK

namespace <namespace_name>;
require_once('PayU.php');
$payu_obj = new PayU();

$payu_obj->env_prod = 0;  //  1 for Live Environment/ 0 for SandBox Environment
    $payu_obj->key = '<key>';
    $payu_obj->salt = '<salt>';

    $res = $payu_obj->initGateway();

    public function showPaymentForm($params) {
        ?>
        <form action="<?= $this->url; ?>" id="payment_form_submit" method="post">
            <input type="hidden" id="surl" name="surl" value="<?= self::SUCCESS_URL; ?>" />
            <input type="hidden" id="furl" name="furl" value="<?= self::FAILURE_URL; ?>" />
            <input type="hidden" id="key" name="key" value="<?= $this->key; ?>" />
            <input type="hidden" id="txnid" name="txnid" value="<?= $params['txnid'] ?>" />
            <input type="hidden" id="amount" name="amount" value="<?= $params['amount']; ?>" />
            <input type="hidden" id="productinfo" name="productinfo" value="<?= $params['productinfo']; ?>" />
            <input type="hidden" id="firstname" name="firstname" value="<?= $params['firstname']; ?>" />
            <input type="hidden" id="lastname" name="lastname" value="<?= $params['lastname']; ?>" />
            <input type="hidden" id="zipcode" name="zipcode" value="<?= $params['zipcode']; ?>" />
            <input type="hidden" id="email" name="email" value="<?= $params['email']; ?>" />
            <input type="hidden" id="phone" name="phone" value="<?= $params['phone']; ?>" />
            <input type="hidden" id="address1" name="address1" value="<?= $params['address1']; ?>" />
            <input type="hidden" id="city" name="city" value="<?= $params['city']; ?>" />
            <input type="hidden" id="state" name="state" value="<?= $params['state']; ?>" />
            <input type="hidden" id="country" name="country" value="<?= $params['country']; ?>" />
            <input type="hidden" id="hash" name="hash" value="<?= $this->getHashKey($params); ?>" />
        </form>
        <script type="text/javascript">
            document.getElementById("payment_form_submit").submit();
        </script>
        <?php
        return null;
    }

    private function getHashKey($params) {
        return hash('sha512', $this->key . '|' . $params['txnid'] . '|' . $params['amount'] . '|' . $params['productinfo'] . '|' . $params['firstname'] . '|' . $params['email'] . '|' . $params['udf1'] . '|' . $params['udf2'] . '|' . $params['udf3'] . '|' . $params['udf4'] . '|' . $params['udf5'] . '||||||' . $this->salt);
    }

    public function verifyPayment($params) {
       if(!empty($params['txnid'])){
            $transaction = $this->getTransactionByTxnId($params['txnid']);
        }
        else{
            $transaction = $this->getTransactionByPayuId($params['payuid']);
        }
        return $transaction;
    }

  public function getTransaction($params) {
        $command = ($params['type'] == 'time') ? self::GET_TRANSACTION_INFO_API : self::GET_TRANSACTION_DETAILS_API;
        $this->params['data'] = ['var1' => $params['from'], 'var2' => $params['to'], 'command' => $command];
        return $this->execute();
    }

 public function validateUpi($params) {
        $this->params['data'] = ['var1' => $params['vpa'], 'var2' => $params['auto_pay_vpa'], 'command' => self::VALIDATE_UPI_HANLE_API];
        return $this->execute();
    }

 public function cancelRefundTransaction($params) {
        $this->params['data'] = ['var1' => $params['payuid'], 'var2' => $params['txnid'], 'var3' => $params['amount'], 'command' => self::CANCEL_REFUND_API];
        return $this->execute();
    }

    public function checkRefundStatus($params) {
        $this->params['data'] = ['var1' => $params['request_id'], 'command' => self::CHECK_ACTION_STATUS];
        return $this->execute();
    }

    public function checkRefundStatusByPayuId($params) {
        $this->params['data'] = ['var1' => $params['payuid'], 'var2' => 'payuid', 'command' => self::CHECK_ACTION_STATUS];
        return $this->execute();
    }

    public function getTransaction($params) {
        $this->params['data'] = ['var1' => $params['netbanking_code'], 'command' => self::GET_NETBANKING_STATUS_API];
        return $this->execute();
    }

 public function getIssuingBankStatus($params) {
        $this->params['data'] = ['var1' => $params['cardnum'], 'command' => self::GET_ISSUING_BANK_STATUS_API];
        return $this->execute();
    }

 public function getCardBin($params) {
        $this->params['data'] = ['var1' => $params['cardnum'], 'command' => self::GET_CARD_BIN_API];
        return $this->execute();
    }

 public function createPaymentInvoice($params) {
        $this->params['data'] = ['var1' => $params['details'], 'command' => self::CREATE_INVOICE_API];
        return $this->execute();
    }

 public function expirePaymentInvoice($params) {
        $this->params['data'] = ['var1' => $params['txnid'], 'command' => self::EXPIRE_INVOICE_API];
        return $this->execute();
    }

 public function checkEligibleEMIBins($params) {
        $this->params['data'] = ['var1' => $params['bin'], 'var2' => $params['card_num'], 'var3' => $params['bank_name'], 'command' => self::CHECK_ELIGIBLE_BIN_FOR_EMI_API];
        return $this->execute();
    }

 public function getEmiAmount($params) {
        $this->params['data'] = ['var1' => $params['amount'], 'command' => self::GET_EMI_AMOUNT_ACCORDING_TO_INTEREST_API];
        return $this->execute();
    }

 public function getSettlementDetails($params) {
        $this->params['data'] = ['var1' => $params['data'], 'command' => self::GET_SETTLEMENT_DETAILS_API];
        return $this->execute();
    }

 public function getCheckoutDetails($params) {
        $this->params['data'] = ['var1' => $params['data'], 'command' => self::GET_CHECKOUT_DETAILS_API];
        return $this->execute();
    }