Catch Paypal donation response

2024-01-17//2 min read

So you have a donation button and a success donation page? Ok, let's catch the response then!

I have read a lot of articles but didn't find what I needed.

Let's first create a donation form. Go to the Paypal button page and there is a donation button generator.
Just go through all the steps and at the end should have HTML form like this:

<form action="https://www.paypal.com/donate" method="post" target="_top" class=" justify-content-center">
    <input type="hidden" name="hosted_button_id" value="{This value comes from the paypal}"/>
    <input type="hidden" name="custom" value="Some custom data that you need to transfer to the success page"/>
    <input type="hidden" name="item_name" value="This will overwrite the message in the donation popup"/>
    <input type="image" style="width: 180px;" src="/media/images/donate.gif" name="submit" title="PayPal - The safer, easier way to pay online!" alt="Donate with PayPal button"/>
</form>

• name="hosted_button_id" - this contains the unique identifier of the hosted button [required]
• name="custom" - if you need to transfer data that is hidden for the user, you can use this field [optional]
• name="item_name" - can overwrite the message for the user in the donation form. [optiona]

🔗Paypal donation response:

On successful donation, the user can go to the success page via a link on the PayPal success page.
When the user clicks on that link PayPal redirects the user to that page.
PayPal sends information about the donation transaction in GET Parameters.
The serialized request should look like this:

{
  "tx": "123123123123123",
  "st": "Completed",
  "amt": "5.00",
  "cc": "GBP",
  "cm": "Custom Data",
  "item_number": "",
  "item_name": "Thank you for the support!"
}

Here is how I tested it.
I created a success page. I use PHP so I call it just success.php

Here is the PHP code:

<?php
// Define the log file path
$logFile = 'http_requests.log';

// Get the current timestamp
$timestamp = date('Y-m-d H:i:s');

// Log the HTTP method and timestamp
$logData = $_SERVER['REQUEST_METHOD'] . " request at $timestamp";

// If it's a GET request, log the parameters
if ($_SERVER['REQUEST_METHOD'] === 'GET') {
    $logData .= " - Parameters: " . json_encode($_GET);
}

// If it's a POST request, log the POST data
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $logData .= " - POST Data: " . json_encode($_POST);
}

// Append a new line and write to the log file
file_put_contents($logFile, $logData . PHP_EOL, FILE_APPEND);

// Your regular PHP code goes here...

// For demonstration purposes, you can send a response back
echo "Success!";
?>