I thought that the cart is emptied when a user logs out, and I finally tracked it down.
On wp_logout() WordPress runs wp_clear_auth_cookie() function. wp_clear_auth_cookie() triggers the do_action( 'clear_auth_cookie' ); action hook.
WooCommerce's Session handler class then runs it's destroy method on this hook.
add_action( 'clear_auth_cookie', array( $this, 'destroy_session' ) );
The destroy_session() method then calls the wc_empty_cart() function, which is a wrapper for the cart class's empty_cart() method.
WC()->cart->empty_cart( false );
But the key thing here is that the parameter is false. Because when we finally track down the empty_cart() method we see that the default is true.
/**
* Empties the cart and optionally the persistent cart too.
*
* @access public
* @param bool $clear_persistent_cart (default: true)
* @return void
*/
public function empty_cart( $clear_persistent_cart = true ) {
$this->cart_contents = array();
$this->reset();
unset( WC()->session->order_awaiting_payment, WC()->session->applied_coupons, WC()->session->coupon_discount_amounts, WC()->session->cart );
if ( $clear_persistent_cart && get_current_user_id() ) {
$this->persistent_cart_destroy();
}
do_action( 'woocommerce_cart_emptied' );
}
When passing true the persistant_cart_destroy() method is called and it is this method that deletes the meta data where the user's cart is kept.
/**
* Delete the persistent cart permanently.
*
* @access public
* @return void
*/
public function persistent_cart_destroy() {
delete_user_meta( get_current_user_id(), '_woocommerce_persistent_cart' );
}
SO, all of that is to say that I do not think the cart should be emptied when a user logs out and then back in. A little more evidence is that WooCommerce attempts to load the persistent cart as soon as a user logs back in.
/**
* Load the cart upon login
*
* @param mixed $user_login
* @param integer $user
* @return void
*/
function wc_load_persistent_cart( $user_login, $user = 0 ) {
if ( ! $user )
return;
$saved_cart = get_user_meta( $user->ID, '_woocommerce_persistent_cart', true );
if ( $saved_cart )
if ( empty( WC()->session->cart ) || ! is_array( WC()->session->cart ) || sizeof( WC()->session->cart ) == 0 )
WC()->session->cart = $saved_cart['cart'];
}
add_action( 'wp_login', 'wc_load_persistent_cart', 1, 2 );
I would try disabling all other plugins to see if the behavior reverts back to what I think is the normal behavior. From there, you can re-enable them one at a time to isolate the culprit.
