Coupon with 2 differents fixed product discounts based on product IDs in WooCommerce

Question

I have come across

Coupon with 2 different percentage discounts based on product category in Woocommerce

Which shows how to alter % discounts for set categories. I want to implement a summer discount code on my store which gives £20 off to a selection of products.

The coupon code summer21 is set to apply a fixed product discount on only the following allowed product IDs

• 2523, 119800, 119886 & 120253

On 3 of the 4 a £20 discount should apply

But if the product ID = 119886, then only £10 should be discounted

---

I've tried modifying the code to the following, but unfortunately without the desired result. What am I missing?

add_filter( 'woocommerce_coupon_get_discount_amount', 'alter_shop_coupon_data', 20, 5 );
function alter_shop_coupon_data( $round, $discounting_amount, $cart_item, $single, $coupon ){

    ## ---- Your settings ---- ##

    // Related coupons codes to be defined in this array (you can set many)
    $coupon_codes = array('Summer21');

    // Product categories for only £10 discount (IDs, Slugs or Names)
    $product_category10 = array('119886'); // for £10 discount

    $second_discount = 10; // £10

    ## ---- The code: Changing the discount to £10 for specific products ---- ##

    if ( $coupon->is_type('fixed_product') && in_array( $coupon->get_code(), $coupon_codes ) ) {
        if( has_term( $product_category10, 'product_cat', $cart_item['product_id'] ) ){
            $discount = $discounting_amount - $second_discount;
            $round = round( min( $discount, $discounting_amount ), wc_get_rounding_precision() );
        }
    }
    return $round;
}

This code also only changes the cart price, but does not show the correct display prices on the product pages.

Answer 1

Your code contains several mistakes

• has_term() is not applicable, we are using in_array() instead
• Cart item quantity per product is not taken into account.

---

To make this answer work, we apply some steps

First step, coupon settings:

• Title: summer21
• General > Discount type: Fixed product discount
• General > Coupon amount: 20
• Usage restriction > Products: where productID: 2523, 119800, 119886, 120253

Second step, settings inside the code function:

• Coupon codes: set your coupon code in lowercase
• Product IDs, for second discount: 119886
• Set the second discount: 10

So you get:

function filter_woocommerce_coupon_get_discount_amount( $round, $discounting_amount, $cart_item, $single, $coupon ) {   
    // Related coupons codes to be defined in this array
    $coupon_codes = array( 'summer21' );

    // Product IDs, for second discount
    $product_ids = array( 119886 ); 

    // Second discount
    $second_discount = 10;

    // Changing the discount for specific product Ids
    if ( $coupon->is_type('fixed_product') && in_array( $coupon->get_code(), $coupon_codes ) ) {                
        // Search for product ID in array product IDs
        if ( in_array( $cart_item['product_id'], $product_ids ) ) {
            // Get cart item quantity
            $cart_item_qty = is_null( $cart_item ) ? 1 : $cart_item['quantity'];
            
            // Discount
            $discount = $coupon->get_amount() - $second_discount;           
            $discount = $single ? $discount : $discount * $cart_item_qty;
            
            $round = round( min( $discount, $discounting_amount ), wc_get_rounding_precision() );
        }       
    }
    
    return $round;
}
add_filter( 'woocommerce_coupon_get_discount_amount', 'filter_woocommerce_coupon_get_discount_amount', 10, 5 );