WooCommerce: Change payment gateway if Cart Total amount = 0

Question

I want users to have a free checkout for my subscription service if they have 100% discount coupon code for the product. So if cart total gets equal to zero, then there should be no payment gateway and users should be able to signup directly.

I think WooCommerce don't allow working without payment gateway or can be difficult to modify, so I want to change the current payment gateway to "Cash on Delivery" if cart total equals to 0 . I shall change Cash on delivery text to something else later.

Here is link to my dummy development. Use Couponcode: abcd1234 Here is the function that I'm using to hide payment gateways in my functions.php file :

add_filter( 'woocommerce_available_payment_gateways', 'paypal_100' );
function paypal_100($available_gateways) {
      if ( WC()->cart->total == '0' ) {
          unset( $available_gateways);
      }
return $available_gateways;
}

Thanks in advance, Yash

Answer 1

Well, after 6 hours of R & D here is the solution.

I made a minor change in plugins\woocommerce-subscriptions\classes\class-wc-subscriptions-cart.php And everything is working as I wanted. No payment method is required for subscription products if cart total equal to 0.

Before code (Line - 280 ):

public static function cart_needs_payment( $needs_payment, $cart ) {

    if ( self::cart_contains_subscription() ) {

        $is_for_one_period = ( self::get_cart_subscription_length() > 0 && self::get_cart_subscription_length() == self::get_cart_subscription_interval() ) ? true : false;

        if ( $cart->total == 0 && false === $needs_payment && $cart->recurring_total > 0 && false === $is_for_one_period && 'yes' !== get_option( WC_Subscriptions_Admin::$option_prefix . '_turn_off_automatic_payments', 'no' ) ) {
            $needs_payment = true;
        }
    }

After Code:

public static function cart_needs_payment( $needs_payment, $cart ) {

    if ( self::cart_contains_subscription() ) {

        $is_for_one_period = ( self::get_cart_subscription_length() > 0 && self::get_cart_subscription_length() == self::get_cart_subscription_interval() ) ? true : false;

        if ( $cart->total == 0 && false === $needs_payment && $cart->recurring_total > 0 && false === $is_for_one_period && 'yes' !== get_option( WC_Subscriptions_Admin::$option_prefix . '_turn_off_automatic_payments', 'no' ) ) {
            $needs_payment = false;
        }
    }

I just changed "$needs_payment = true;" to "$needs_payment = false;"