This filter can be used to override the output from the pmpro_hasMembershipLevel() function. It passes the boolean true or false, user ID, and the array of required levels for that post passed to pmpro_hasMembershipLevel().
pmpro_cancel_previous_subscriptions
This hook controls whether or not PMPro cancels a user’s previous membership level at checkout, which is enabled at default. This is dangerous, but is useful in certain cases like the PMPro Addon Packages plugin.
pmpro_check_discount_code_levels
This filter controls whether discount codes should only be applied to certain levels. By default, this is set to true, and discount codes are checked to see if they apply to the membership level passed. Return true if the code can be used with the level supplied or false if not.
pmpro_field_classes
Use this to filter the CSS classes added to the fields on the checkout page. This is normally used to handle error highlighting with the “pmpro_error” class.
This returns the CSS classes and the current the current field name to be applied to.
pmpro_after_change_membership_level
Use this hook to execute custom code after a user’s membership level is changed or cancelled. This hook passes the new level ID, the user ID of the WordPress user, and the level ID being cancelled (if specified).