NAME Business::PayPal::IPN - Perl extension that implements PayPal IPN v1.4 SYNOPSIS use Business::PayPal::IPN; my $ipn = new Business::PayPal::IPN() or die Business::PayPal::IPN->error(); # if we came this far, you're guaranteed it went through, # and the transaction took place. But now you need to check # the status of the transaction, to see if it was completed # or still pending if ( $ipn->completed ) { # do something with it } DESCRIPTION Business::PayPal::IPN implements PayPal IPN version 1.4. It validates transactions and gives you means to get notified of payments to your PayPal account. If you don't already know what PayPal IPN is this library may not be for you ;-). Consult with respective manuals provided by PayPal.com. WARNING $Revision: 1.4 $ of Business::PayPal::IPN supports version 1.4 of the API. This was the latest version as of Wednesday, January 22, 2003. Supported version number is available in $Business::PayPal::IPN::SUPPORTEDV global variable. Note: If PayPal introduces new response variables, Business::PayPal::IPN automatically supports those variables thanks to AUTOLOAD. For any further updates, you can contact me or send me a patch. PAYPAL IPN OVERVIEW As soon as you receive payment to your PayPal account, PayPal posts the transaction details to your specified URL, which you either configure in your PayPal preferences, or in your HTML forms' "notify_url" hidden field. When the payment details are received from, supposedly, PayPal server, your application should check with the PayPal server to make sure it is indeed a valid transaction, and that PayPal is aware of it. This can be achieved by re-submitting the transaction details back to https://www.paypal.com/cgi-bin/webscr and check the integrity of the data. If the transaction is valid, PayPal will respond to you with a single string "VERIFIED", and you can proceed safely. If the transaction is not valid, you will receive "INVALID", and you can log the request for further investigation. Business::PayPal::IPN is the library which encapsulates all the above complexity into this compact form: my $ipn = new Business::PayPal::IPN() or die Business::PayPal::IPN->error(); # if we come this far, we're guaranteed it was a valid transaction. if ( $ipn->completed() ) { # means the funds are already in our paypal account. But we should # still check against duplicates transaction ids to ensure we're # not logging the same transaction twice. } elsif ( $ipn->pending() ) { # the payment was made to your account, but its status is still pending # $ipn->pending() also returns the reason why it is so. } elsif ( $ipn->denied() ) { # the payment denied } elsif ( $ipn->failed() ) { # the payment failed } PREREQUISITES * LWP - to make HTTP requests * Crypt::SSLeay - to enable LWP perform https (SSL) requests. If for any reason you are not able to install Crypt::SSLeay, you will need to update $Business::PayPal::IPN::GTW to proper, non-ssl URL. METHODS * "new()" - constructor. Validates the transaction and returns IPN object if everything was successful. Optionally you may pass it query and ua options. query denotes the CGI object to be used. ua denotes the user agent object. If ua is missing, it will use LWP::UserAgent by default. * "query()" - can also be accessed via "cgi()" alias, returns respective query object * "response()" - returns HTTP::Response object, which is the content returned while verifying transaction through PayPal. You normally never need this method. In case you do for any reason, here it is. * "user_agent()" - returns user agent object used by the library to verify the transaction. Name of the agent is "Business::PayPal::IPN/#.# (libwww-perl/#.##)". Business::PayPal::IPN supports all the variables supported by PayPal IPN independent of its version. To access the value of any variable, use the corresponding method name. For example, if you want to get the first name of the user who made the payment ('first_name' variable): my $fname = $ipn->first_name(); To get the transaction id ('txn_id' variable): my $txn = $ipn->txn_id(); To get payment type ('payment_type' variable) $type = $ipn->payment_type(); and so on. For the list of all the available variables, consult IPN Manual provided by PayPal Developer Network. You can find the link at the bottom of http://www.paypal.com. In addition to the above scheme, the library also provides convenience methods such as: * "status()" - which is a shortcut to "payment_status()" * "failed()" - returns true if "payment_status" is "Failed". * "completed()" - returns true if "payment_status" is "Completed". * "pending()" - returns true if "payment_status" is "Pending". Return value is also the string that explains why the payment is pending. "denied()" - returns true if "payment_status" is "Denied". VARIABLES Following global variables are available: * $Business::PayPal::IPN::GTW - gateway url to PayPal's Web Script. Default is "https://www.paypal.com/cgi-bin/webscr", which you may not want to change. But it comes handy while testing your application through a PayPal simulator. * $Business::PayPal::IPN::SUPPORTEDV - supported version of PayPal's IPN API. Default value is "1.4". You can modify it before creating ipn object (as long as you know what you are doing. If not don't touch it!) * $Business::PayPal::IPN::VERSION - version of the library AUTHOR Sherzod B. Ruzmetov CREDITS Thanks to Brian Grossman for his patches. COPYRIGHT AND LICENSE Copyright 2003 by Sherzod B. Ruzmetov. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. THIS LIBRARY IS PROVIDED WITH THE USEFULNESS IN MIND, BUT WITHOUT EVEN IMPLIED GUARANTEE OF MERCHANTABILITY NOR FITNESS FOR A PARTICULAR PURPOSE. USE IT AT YOUR OWN RISK. REVISION $Revision: 1.4 $