This development guide is a reference for adding new payment processor to Subscription plug-in.
All processors should be located in processors folder. When creating a new processor files, it's easiest to copy the file structure from an existing one. The files are as follows:
info.php contains basic info on gateway, used to show new gateway in the gateway list
Gateway class should be named using the following rule: <gateway_name>.class.php, this allows us to load it automatically when needed
ipn_url_manager.class.php -
URL handler class that handles IPN calls, this file is optional, depends on how the gateway works.
img folder contains default subscription button image
lang folder contains language files for gateway specific text
templates folder contains templates for forms used for gateway (for settings page, for checkout page, and optionally for unsubscribe link, if supported)
All gateway related functionality is encapsulated in gateway class, and it extends Payment_gateway class. To implement gateway specific logic you should overload the following methods:
constructor() - set specific fields to their default values
set_test_method() - set gateway in test mode, if supported
get_settings_form() - generate
HTML for settings form, based on VTE template settings.xml
register_ipn() / unregister_ipn() - if gateway supports IPN or similar method of server to server notification use this methods to register
URL handlers
process_ipn() - this method should handle the IPN call, and act upon it
subscribe() - generate subscription, usually called from process_ipn() method
get_checkout_button() - generates
HTML code for checkout form (subscribe button), based on VTE template subscribe.xml
save_settings() - used to save gateway specific settings to Configuration table
transaction_log() - used to save transaction data to Subscription_log table
For more details on these and other gateway related methods please consult the inline documentation in the code.
