Paynow Integration Part 5: Checking for payments

Once you have requested for a transaction to take place the next steps includes

• Checking transaction status
• Taking the correct action(giving or denying access)

In this tutorial we check if Paynow transaction has succeeded they can the correct action.

Checking if transaction is taking place

In the last part we send a transaction to Paynow and Paynow did send a dialog to our customer.

So to check if that succeeded we use this code:

if($response->success()) {
    // Check if payment is successful
}

If its true then it mean the transaction is taking place!

Checking if transaction is successful

Now lets check if the user paid

if($response->success()) {
    $pollUrl = $response->pollUrl();

    // Check the status of the transaction
    $status = $paynow->pollTransaction($pollUrl);

    if($status->paid()) {
        // Yay! Transaction was paid for
    } else {
        // No! It wasn't paid for
    }
}

So the first thing is getting a poll URL

$pollUrl = $response->pollUrl();

Then use that URL to get the status of the payment

$status = $paynow->pollTransaction($pollUrl);

Then you check the status

if($status->paid()) {
    // Some success code here
}else{
    // Some fail code here
}

This is theoretically correct but practically wrong because a real world mobile transaction can take from 8 seconds to 30 seconds.

The user has to put pin, verify if its correct then press accept, by then the code above who have announced it as a failed transaction.

So we must give some kind of grace period to the transaction checking process. To do that we use a loop plus sleep function.

$timeout = 9;
$count = 0;

while(true){
   sleep(3);

   //Check if paid
   if($status->paid()){
         // Yay! Transaction was paid for
   }

   $count++;

   if ($count > $timeout){
       // Timeout reached
    }

}

Complete Code

So the whole code from part 1 to this part will look like this:

<?php


$phone = $_POST["phone_number"]; // Sanitize data
$platform = "";

$user_email = filter_var($_POST['user_email'], FILTER_SANITIZE_EMAIL);
$invoice_name = "Invoice " . time();

$cart_id = $_POST['cart_id'];   // Sanitize id
$products = $this->get_cart_products($cart_id);


// Initialize Paynow
$paynow = new Paynow\Payments\Paynow(
    'INTEGRATION_ID',
    'INTEGRATION_KEY',
    'http://example.com/gateways/paynow/update',
    'http://example.com/return?gateway=paynow'
);

// Create Payments
$invoice_name = "Invoice " . time();
$payment = $paynow->createPayment($invoice_name, $user_email);

// Add some products
foreach($products as $product){
     $payment->add($product->name, $product->price);
}

// Detect platform and send payment
if(str_starts_with($phone, '071')){
     $platform= "onemoney";
}else if(str_starts_with($phone, '073')){
    $platform = "telecash";
}else{
    $platform = "ecocash";
}

$response = $paynow->sendMobile($payment, $phone, $platform);

// Check transaction success
if($response->success()) {
    // Get transaction poll URL
    $pollUrl = $response->pollUrl();



     $timeout = 9;
     $count = 0;

     while(true){
         sleep(3);
         // Get the status of the transaction
         $status = $paynow->pollTransaction($pollUrl);



         //Check if paid
         if($status->paid()){
           // Yay! Transaction was paid for
           // Save transactions to database and grant access
          }

          $count++;

          if ($count > $timeout){
             // Timeout reached
           }
      }
}

// Transaction failed

So that's it guys, go ahead and get paid, enjoy the rest of the week.