ideadude

<?php
/**
 * Change the default PMPro WooCommerce bahavior
 * and make membership products not purchasable
 * if a user already has any other membership level.
 */
// First disable the core PMPro WC callaback and set up our own.
function my_pmprowoo_init() {
	remove_filter( 'woocommerce_is_purchasable', 'pmprowoo_is_purchasable', 10, 2 );
	add_filter( 'woocommerce_is_purchasable', 'my_pmprowoo_is_purchasable', 5, 2 );

strangerstudios

/*
	When users cancel (are changed to membership level 0) we give them another "cancelled" level. Can be used to downgrade someone to a free level when they cancel.
*/
function pmpro_after_change_membership_level_default_level($level_id, $user_id)
{
	//if we see this global set, then another gist is planning to give the user their level back
	global $pmpro_next_payment_timestamp;
	if(!empty($pmpro_next_payment_timestamp))
		return;