James Andrews

Paypal IPN Listener class.

Oct 4, 2010 in PHP Development by jandrews | 2 Comments

define('PAYPAL_IPN_LISTENER_VERIFIED_STATUS','VERIFIED');
define('PAYPAL_IPN_LISTENER_INVALID_STATUS','INVALID');

class PaypalIPNListener
{
    protected $status = PAYPAL_IPN_LISTENER_INVALID_STATUS;
    protected $payment_status = false;
    private $sandboxUrl = "https://www.sandbox.paypal.com/cgi-bin/webscr";
    private $productionUrl = "https://www.paypal.com/cgi-bin/webscr";
    private $serviceUrl = null;
    private $serviceData = "";
    
    public function __construct($postData = array(), $sandbox=false)
    {
		// Set the initial serviceUrl
		$serviceUrl = $productionUrl;

		// If sandbox change the serviceUrl
		if($sandbox == true) $serviceUrl = $sandboxUrl;

        // Save the post data for later use.
        $this->postData = $postData;

        // If we are debugging switch the URL
        $serviceUrl =  ($sandbox) ? $sandboxUrl : $productionUrl;
        
        // Add the validate notify command to the post data.
        $postData['cmd'] = '_notify-validate';
        
        // Create a querystring from the data.
        foreach($postData as $key => $val)
        {
                if($serviceData != "") $responseData .="&";
                $serviceData .= $key . "=" . urlencode($val);
        }

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $this->serviceUrl);
        curl_setopt($ch, CURLOPT_FAILONERROR, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
        $output = curl_exec($ch);
        
        // If the payment is verified then set the status as verified.
        if($output == "VERIFIED")
        {
            $this->status = PAYPAL_IPN_LISTENER_VERIFIED_STATUS;
            $this->payment_status = $postData['payment_status'];
        }
        
    }

    public function getPaymentStatus()
    {
    	return $this->payment_status;
    }

    public function __toString()
    {
        return $this->status;
    }
}

// Create the IPN Listener object. (passing true as the 2nd parameter
// sets you up with the sandbox for development.
$ipn = new PaypalIPNListener($_POST, true);

// IPN Listener Object
$ipn = new PaypalIPNListener($_POST, true);

if($ipn == PAYPAL_IPN_LISTENER_VERIFIED_STATUS)
{
    // Payment is verified.   We use the magic method __toString to return the validation status.
    // Then it's as simple as checking the $_POST data for the ['payment_status'] to make sure they
   // weren't denied or that something didn't go wrong on paypals side.
}
else
{
    // something went wrong with the validation process.  You should handle it here.
    // at least log it so that you have a record of the failed validation.
}