Print Paypal IPN variables to the screen

Question

This is my first post in this forum :) I am not good in english, so I apologize for my mistakes.

Here is the problem - I have Paypal IPN files (code below), that sends variables to e-mail. I do not want to get them in the mail, after payment I want to print them on the browser screen. Can you help me to do this?

callback.php

<?php
ini_set('log_errors', true);
ini_set('error_log', dirname(__FILE__).'/ipn_errors.log');


// instantiate the IpnListener class
include('ipnlistener.php');
$listener = new IpnListener();


/*
When you are testing your IPN script you should be using a PayPal "Sandbox"
account: https://developer.paypal.com
When you are ready to go live change use_sandbox to false.
*/
$listener->use_sandbox = false;

/*
By default the IpnListener object is going  going to post the data back to PayPal
using cURL over a secure SSL connection. This is the recommended way to post
the data back, however, some people may have connections problems using this
method. 

To post over standard HTTP connection, use:
$listener->use_ssl = false;

To post using the fsockopen() function rather than cURL, use:
$listener->use_curl = false;
*/

/*
The processIpn() method will encode the POST variables sent by PayPal and then
POST them back to the PayPal server. An exception will be thrown if there is 
a fatal error (cannot connect, your server is not configured properly, etc.).
Use a try/catch block to catch these fatal errors and log to the ipn_errors.log
file we setup at the top of this file.

The processIpn() method will send the raw data on 'php://input' to PayPal. You
can optionally pass the data to processIpn() yourself:
$verified = $listener->processIpn($my_post_data);
*/
try {
    $listener->requirePostMethod();
    $verified = $listener->processIpn();
} catch (Exception $e) {
    error_log($e->getMessage());
    exit(0);
}


/*
The processIpn() method returned true if the IPN was "VERIFIED" and false if it
was "INVALID".
*/
if ($verified) {
    /*
    Once you have a verified IPN you need to do a few more checks on the POST
    fields--typically against data you stored in your database during when the
    end user made a purchase (such as in the "success" page on a web payments
    standard button). The fields PayPal recommends checking are:

        1. Check the $_POST['payment_status'] is "Completed"
        2. Check that $_POST['txn_id'] has not been previously processed 
        3. Check that $_POST['receiver_email'] is your Primary PayPal email 
        4. Check that $_POST['payment_amount'] and $_POST['payment_currency'] 
           are correct

    Since implementations on this varies, I will leave these checks out of this
    example and just send an email using the getTextReport() method to get all
    of the details about the IPN.  
    */
    mail('my@mail.com', 'Valid IPN', $listener->getTextReport());
} else {
    /*
    An Invalid IPN *may* be caused by a fraudulent transaction attempt. It's
    a good idea to have a developer or sys admin manually investigate any 
    invalid IPN.
    */
    mail('my@mail.com', 'Invalid IPN', $listener->getTextReport());
}

?>

ipnlistener.php

<?php
class IpnListener {

    /**
     *  If true, the recommended cURL PHP library is used to send the post back 
     *  to PayPal. If flase then fsockopen() is used. Default true.
     *
     *  @var boolean
     */
    public $use_curl = true;     

    /**
     *  If true, explicitly sets cURL to use SSL version 3. Use this if cURL
     *  is compiled with GnuTLS SSL.
     *
     *  @var boolean
     */
    public $force_ssl_v3 = true;     

    /**
     *  If true, cURL will use the CURLOPT_FOLLOWLOCATION to follow any 
     *  "Location: ..." headers in the response.
     *
     *  @var boolean
     */
    public $follow_location = false;     

    /**
     *  If true, an SSL secure connection (port 443) is used for the post back 
     *  as recommended by PayPal. If false, a standard HTTP (port 80) connection
     *  is used. Default true.
     *
     *  @var boolean
     */
    public $use_ssl = true;      

    /**
     *  If true, the paypal sandbox URI www.sandbox.paypal.com is used for the
     *  post back. If false, the live URI www.paypal.com is used. Default false.
     *
     *  @var boolean
     */
    public $use_sandbox = false; 

    /**
     *  The amount of time, in seconds, to wait for the PayPal server to respond
     *  before timing out. Default 30 seconds.
     *
     *  @var int
     */
    public $timeout = 30;       

    private $post_data = array();
    private $post_uri = '';     
    private $response_status = '';
    private $response = '';

    const PAYPAL_HOST = 'www.paypal.com';
    const SANDBOX_HOST = 'www.sandbox.paypal.com';

    /**
     *  Post Back Using cURL
     *
     *  Sends the post back to PayPal using the cURL library. Called by
     *  the processIpn() method if the use_curl property is true. Throws an
     *  exception if the post fails. Populates the response, response_status,
     *  and post_uri properties on success.
     *
     *  @param  string  The post data as a URL encoded string
     */
    protected function curlPost($encoded_data) {

        if ($this->use_ssl) {
            $uri = 'https://'.$this->getPaypalHost().'/cgi-bin/webscr';
            $this->post_uri = $uri;
        } else {
            $uri = 'http://'.$this->getPaypalHost().'/cgi-bin/webscr';
            $this->post_uri = $uri;
        }

        $ch = curl_init();

        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
        curl_setopt($ch, CURLOPT_CAINFO, 
                    dirname(__FILE__)."/cert/api_cert_chain.crt");
        curl_setopt($ch, CURLOPT_URL, $uri);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $encoded_data);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $this->follow_location);
        curl_setopt($ch, CURLOPT_TIMEOUT, $this->timeout);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, true);

        if ($this->force_ssl_v3) {
            curl_setopt($ch, CURLOPT_SSLVERSION, 3);
        }

        $this->response = curl_exec($ch);
        $this->response_status = strval(curl_getinfo($ch, CURLINFO_HTTP_CODE));

        if ($this->response === false || $this->response_status == '0') {
            $errno = curl_errno($ch);
            $errstr = curl_error($ch);
            throw new Exception("cURL error: [$errno] $errstr");
        }
    }

    /**
     *  Post Back Using fsockopen()
     *
     *  Sends the post back to PayPal using the fsockopen() function. Called by
     *  the processIpn() method if the use_curl property is false. Throws an
     *  exception if the post fails. Populates the response, response_status,
     *  and post_uri properties on success.
     *
     *  @param  string  The post data as a URL encoded string
     */
    protected function fsockPost($encoded_data) {

        if ($this->use_ssl) {
            $uri = 'ssl://'.$this->getPaypalHost();
            $port = '443';
            $this->post_uri = $uri.'/cgi-bin/webscr';
        } else {
            $uri = $this->getPaypalHost(); // no "http://" in call to fsockopen()
            $port = '80';
            $this->post_uri = 'http://'.$uri.'/cgi-bin/webscr';
        }

        $fp = fsockopen($uri, $port, $errno, $errstr, $this->timeout);

        if (!$fp) { 
            // fsockopen error
            throw new Exception("fsockopen error: [$errno] $errstr");
        } 

        $header = "POST /cgi-bin/webscr HTTP/1.1\r\n";
        $header .= "Host: ".$this->getPaypalHost()."\r\n";
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
        $header .= "Content-Length: ".strlen($encoded_data)."\r\n";
        $header .= "Connection: Close\r\n\r\n";

        fputs($fp, $header.$encoded_data."\r\n\r\n");

        while(!feof($fp)) { 
            if (empty($this->response)) {
                // extract HTTP status from first line
                $this->response .= $status = fgets($fp, 1024); 
                $this->response_status = trim(substr($status, 9, 4));
            } else {
                $this->response .= fgets($fp, 1024); 
            }
        } 

        fclose($fp);
    }

    private function getPaypalHost() {
        if ($this->use_sandbox) return self::SANDBOX_HOST;
        else return self::PAYPAL_HOST;
    }

    /**
     *  Get POST URI
     *
     *  Returns the URI that was used to send the post back to PayPal. This can
     *  be useful for troubleshooting connection problems. The default URI
     *  would be "ssl://www.sandbox.paypal.com:443/cgi-bin/webscr"
     *
     *  @return string
     */
    public function getPostUri() {
        return $this->post_uri;
    }

    /**
     *  Get Response
     *
     *  Returns the entire response from PayPal as a string including all the
     *  HTTP headers.
     *
     *  @return string
     */
    public function getResponse() {
        return $this->response;
    }

    /**
     *  Get Response Status
     *
     *  Returns the HTTP response status code from PayPal. This should be "200"
     *  if the post back was successful. 
     *
     *  @return string
     */
    public function getResponseStatus() {
        return $this->response_status;
    }

    /**
     *  Get Text Report
     *
     *  Returns a report of the IPN transaction in plain text format. This is
     *  useful in emails to order processors and system administrators. Override
     *  this method in your own class to customize the report.
     *
     *  @return string
     */
    public function getTextReport() {

        $r = '';

        // date and POST url
        for ($i=0; $i<80; $i++) { $r .= '-'; }
        $r .= "\n[".date('m/d/Y g:i A').'] - '.$this->getPostUri();
        if ($this->use_curl) $r .= " (curl)\n";
        else $r .= " (fsockopen)\n";

        // HTTP Response
        for ($i=0; $i<80; $i++) { $r .= '-'; }
        $r .= "\n{$this->getResponse()}\n";

        // POST vars
        for ($i=0; $i<80; $i++) { $r .= '-'; }
        $r .= "\n";

        foreach ($this->post_data as $key => $value) {
            $r .= str_pad($key, 25)."$value\n";
        }
        $r .= "\n\n";

        return $r;
    }

    /**
     *  Process IPN
     *
     *  Handles the IPN post back to PayPal and parsing the response. Call this
     *  method from your IPN listener script. Returns true if the response came
     *  back as "VERIFIED", false if the response came back "INVALID", and 
     *  throws an exception if there is an error.
     *
     *  @param array
     *
     *  @return boolean
     */    
    public function processIpn($post_data=null) {

        $encoded_data = 'cmd=_notify-validate';

        if ($post_data === null) { 
            // use raw POST data 
            if (!empty($_POST)) {
                $this->post_data = $_POST;
                $encoded_data .= '&'.file_get_contents('php://input');
            } else {
                throw new Exception("No POST data found.");
            }
        } else { 
            // use provided data array
            $this->post_data = $post_data;

            foreach ($this->post_data as $key => $value) {
                $encoded_data .= "&$key=".urlencode($value);
            }
        }

        if ($this->use_curl) $this->curlPost($encoded_data); 
        else $this->fsockPost($encoded_data);

        if (strpos($this->response_status, '200') === false) {
            throw new Exception("Invalid response status: ".$this->response_status);
        }

        if (strpos($this->response, "VERIFIED") !== false) {
            return true;
        } elseif (strpos($this->response, "INVALID") !== false) {
            return false;
        } else {
            throw new Exception("Unexpected response from PayPal.");
        }
    }

    /**
     *  Require Post Method
     *
     *  Throws an exception and sets a HTTP 405 response header if the request
     *  method was not POST. 
     */    
    public function requirePostMethod() {
        // require POST requests
        if ($_SERVER['REQUEST_METHOD'] && $_SERVER['REQUEST_METHOD'] != 'POST') {
            header('Allow: POST', true, 405);
            throw new Exception("Invalid HTTP request method.");
        }
    }
}

Credit belongs to Micah Carrick

Answer 1

If you really need to display the IPN message variables on the screen, you will first need to write all the variables sent in the IPN message to a database. Then, you can call that database entry and view any of the information you need. By default, IPN is not going to show any information on the screen. It just isn't supposed to work that way.

Answer 2

IPN is a behind the scenes function. Why are you trying to print them to the screen? The buyer should not be returning to this page, so no one would be seeing what you are trying to print to the screen. If you are trying to print the information to the screen to create a dynamic type of receipt, then you would want to use PDT for this. Also, IPN is an asynchronous message service, meaning that messages are not synchronized with actions on your website. Thus, listening for an IPN message does not increase the time it takes to complete a transaction on your website.

The IPN message service does not assume that all messages will be received by your listener in a timely manner. Because the internet is not 100% reliable, messages can become lost or delayed. To handle the possibility of transmission and receipt delays or failures, the IPN message service implements a retry mechanism that resends messages at various intervals until you acknowledge that the message has successfully been received. Messages may be resent for up to four days after the original message.