How do I dynamically change the coupon amount and display it in the cart totals in WooCommerce

Question

I have created a Woocommerce coupon with a discount type set to fixed cart discount and an initial coupon amount.

I want the coupon to function in such a way that when the customer enters the coupon code the total discount is computed and is set as the coupon amount. I'm using the woocommerce_applied_coupon hook in the theme's function.php.

Here's how I coded:

add_action( 'woocommerce_applied_coupon', 'action_woocommerce_applied_coupon', 10, 3 );

function action_woocommerce_applied_coupon( $array, $int, $int ){
  $total_discount = 0;
  $wc = wc();//use the WC class

  foreach($wc->cart->get_cart() as $cart_item){
    //loop through each cart line item

    $total_discount += ...; //this is where the total discount is computed
  }

  //use the WC_COUPON class
  $wc_coupon = new WC_Coupon("coupon-code");// create an instance of the class using the coupon code
  $wc_coupon->set_amount($total_discount);//set coupon amount to the computed discounted price
  var_dump($wc_coupon->get_amount());//check if the coupon amount did update
}

The var_dump displayed the $total_discount. But when I checked on the Cart Totals, I still see the initial coupon amount as the discount.

How do I get to update the coupon amount and apply this as the discount to the cart totals?

I think you need to update cart line related to the coupon, var_dump cart or have a look t the WC_Cart class, hope this helps a bit. — JBoulhous

shaun shaun · Accepted Answer · 2018-07-03T15:03:54

Try this

add_action( 'woocommerce_before_calculate_totals', 'auto_add_coupons_total_based', 10, 1 ); function auto_add_coupons_total_based( $cart ) {

if ( is_admin() && ! defined( 'DOING_AJAX' ) )
    return;

// HERE define your coupon code
$coupon_percent = 'xyz20'; # <===  <===  <===  <===  <===  <===
$coupon_fixed = 'fixedamount'; # <===  <===  <===  <===  <===  <===  <===

// Get cart subtotal
$subtotal = 0;
foreach($cart->get_cart() as $cart_item ){
    $subtotal += $cart_item['line_subtotal'];
    $subtotal += $cart_item['line_subtotal_tax']; // with taxes
}

//Set HERE the limit amount
$limit = 40; //without Tax


// Coupon type "percent" (less than 200)
if( $subtotal < 200 && ! $cart->has_discount( $coupon_percent ) ){
    // If coupon "fixed amount" type is in cart we remove it
    if( $cart->has_discount( $coupon_fixed ) )
        $cart->remove_coupon( $coupon_fixed );


}
// Coupon type "fixed amount" (Up to 200)
if( $subtotal >= 200 && $cart->has_discount( $coupon_percent ) ) {
    // If coupon "percent" type is in cart we remove it
    if( $cart->has_discount( $coupon_percent ) )
        $cart->remove_coupon( $coupon_percent );

    // Apply the "fixed amount" type coupon code
    $cart->add_discount( $coupon_fixed );


    // Displaying a custom message
        $message = __( "The total discount limit of $$limit has been reached", "woocommerce" );
        wc_add_notice( $message, 'notice' );



}

}

How do I dynamically change the coupon amount and display it in the cart totals in WooCommerce

1 Answers