add_field('business', 'somebody@domain.com'); * $p->add_field('first_name', $_POST['first_name']); * ... (add all your fields in the same manor) * $p->submit_paypal_post(); * * To process an IPN, have your IPN processing file contain: * * $p = new paypal_class; * if ($p->validate_ipn()) { * ... (IPN is verified. Details are in the ipn_data() array) * } * * * In case you are new to paypal, here is some information to help you: * * 1. Download and read the Merchant User Manual and Integration Guide from * http://www.paypal.com/en_US/pdf/integration_guide.pdf. This gives * you all the information you need including the fields you can pass to * paypal (using add_field() with this class) aswell as all the fields * that are returned in an IPN post (stored in the ipn_data() array in * this class). It also diagrams the entire transaction process. * * 2. Create a "sandbox" account for a buyer and a seller. This is just * a test account(s) that allow you to test your site from both the * seller and buyer perspective. The instructions for this is available * at https://developer.paypal.com/ as well as a great forum where you * can ask all your paypal integration questions. Make sure you follow * all the directions in setting up a sandbox test environment, including * the addition of fake bank accounts and credit cards. * ******************************************************************************* */ class paypal_class { var $last_error; // holds the last error encountered var $ipn_log; // bool: log IPN results to text file? var $ipn_log_file; // filename of the IPN log var $ipn_response; // holds the IPN response from paypal var $ipn_data = array(); // array contains the POST values for IPN var $fields = array(); // array holds the fields to submit to paypal function paypal_class() { // initialization constructor. Called when class is created. $this->paypal_url = 'https://www.paypal.com/cgi-bin/webscr'; $this->last_error = ''; $this->ipn_log_file = 'ipn_log.txt'; $this->ipn_log = true; $this->ipn_response = ''; // populate $fields array with a few default values. See the paypal // documentation for a list of fields and their data types. These defaul // values can be overwritten by the calling script. $this->add_field('rm','2'); // Return method = POST $this->add_field('cmd','_xclick'); } function add_field($field, $value) { // adds a key=>value pair to the fields array, which is what will be // sent to paypal as POST variables. If the value is already in the // array, it will be overwritten. $this->fields["$field"] = $value; } function submit_paypal_post() { // this function actually generates an entire HTML page consisting of // a form with hidden elements which is submitted to paypal via the // BODY element's onLoad attribute. We do this so that you can validate // any POST vars from you custom form before submitting to paypal. So // basically, you'll have your own form which is submitted to your script // to validate the data, which in turn calls this function to create // another hidden form and submit to paypal. // The user will briefly see a message on the screen that reads: // "Please wait, your order is being processed..." and then immediately // is redirected to paypal. echo "\n"; echo "Processing Payment...\n"; echo "\n"; echo "

Please wait, your order is being processed...

\n"; echo "
paypal_url."\">\n"; foreach ($this->fields as $name => $value) { echo ""; } echo "
\n"; echo "\n"; } function validate_ipn() { // parse the paypal URL $url_parsed=parse_url($this->paypal_url); // generate the post string from the _POST vars aswell as load the // _POST vars into an arry so we can play with them from the calling // script. $post_string = ''; foreach ($_POST as $field=>$value) { $this->ipn_data["$field"] = $value; $post_string .= $field.'='.urlencode($value).'&'; } $post_string.="cmd=_notify-validate"; // append ipn command // open the connection to paypal $fp = fsockopen("https://$url_parsed[host]","80",$err_num,$err_str,30); if(!$fp) { // could not open the connection. If loggin is on, the error message // will be in the log. $this->last_error = "fsockopen error no. $errnum: $errstr, host: $url_parsed[host]"; $this->log_ipn_results(false); return false; } else { // Post the data back to paypal fputs($fp, "POST $url_parsed[path] HTTP/1.1\r\n"); fputs($fp, "Host: $url_parsed[host]\r\n"); fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n"); fputs($fp, "Content-length: ".strlen($post_string)."\r\n"); fputs($fp, "Connection: close\r\n\r\n"); fputs($fp, $post_string . "\r\n\r\n"); // loop through the response from the server and append to variable while(!feof($fp)) { $this->ipn_response .= fgets($fp, 1024); } fclose($fp); // close connection } if (eregi("VERIFIED",$this->ipn_response)) { // Valid IPN transaction. $this->log_ipn_results(true); return true; } else { // Invalid IPN transaction. Check the log for details. $this->last_error = 'IPN Validation Failed.'; $this->log_ipn_results(false); return false; } } function log_ipn_results($success) { if (!$this->ipn_log) return; // is logging turned off? // Timestamp date_default_timezone_set("UTC"); $text = '['.date('m/d/Y g:i A').'] - '; // Success or failure being logged? if ($success) $text .= "SUCCESS!\n"; else $text .= 'FAIL: '.$this->last_error."\n"; // Log the POST variables $text .= "IPN POST Vars from Paypal:\n"; foreach ($this->ipn_data as $key=>$value) { $text .= "$key=$value, "; } // Log the response from the paypal server $text .= "\nIPN Response from Paypal Server:\n ".$this->ipn_response; // Write to log $fp=fopen($this->ipn_log_file,'a'); fwrite($fp, $text . "\n\n"); fclose($fp); // close file } function dump_fields() { // Used for debugging, this function will output all the field/value pairs // that are currently defined in the instance of the class using the // add_field() function. echo "

paypal_class->dump_fields() Output:

"; echo ""; ksort($this->fields); foreach ($this->fields as $key => $value) { echo ""; } echo "
Field Name Value
$key".urldecode($value)." 

"; } }