I am having a peculiar problem implementing recurring payment for a webapp that I am developing. I could not use a hosted paypal subscription button, because the payment sum would be variable. So, I used a non hosted solution something like this :
<form action="https://www.sandbox.paypal.com/us/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_xclick-subscriptions">
<input type="hidden" name="business" value="business@email.com">
<input type="hidden" name="item_name" value="Some item"/>
<input type="hidden" name="return" value="return_url">
<input type="hidden" name="cancel_return" value="cancel_url">
<input type="hidden" name="notify_url" value="notification_url">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="no_shipping" value="1">
<input type="image" src="http://www.paypal.com/en_US/i/btn/btn_subscribe_LG.gif" border="0" name="submit" alt="Make payments with PayPal - it's fast, free and secure!">
<input type="hidden" name="a3" value="variable_amount">
<input type="hidden" name="p3" value="1">
<input type="hidden" name="t3" value="M">
<input type="hidden" name="rm" value="2">
<input type="hidden" name="src" value="1">
<input type="hidden" name="sra" value="1">
<input type="hidden" name="custom" value="planid1,planid2"/>
</form>
Now, I need to check every month using a cron that who has paid, and generate content according to that.
From the discussions all over the internet, it is clear that paypal doesn't send txn_id for the subscription. So, how am I supposed to check if user has paid in the next month or not? One thing that comes to my mind is an IPN listener, but will that work with a non-hosted button? Totally confused with this. Could someone point me to the right direction?
