Don’t apply other coupon discounts to a BOGO/Free product

[anthonyceo]

I want to allow multiple coupons, but don’t want any other coupons to apply further discounts to any products that are buy 1 get 1 free.

(e.g. I want to use a 20% off coupon with a BOGO coupon. But I don’t want the BOGO item to have this 20% discount)

How can I accomplish this with the plugin or a filter? I think I need to do this with a filter as it’s too much work selecting all the exclusions for every new coupon.

[Soft79]

I think you could use http://hookr.io/filters/woocommerce_coupon_is_valid_for_product/ for that… return false if the discount shouldn’t apply.

[anthonyceo]

Hmmm, the $coupon object isn’t in that filter. Just $bool and $product. Scratching my head.

[Soft79]

Yes it is, it’s the 3rd argument.

[anthonyceo]

Thank you. It seems to work.

However, I’m determining what products have free products through custom meta data. In this case, the meta data for free products is called hide_sub.

I don’t want to do it this way. It also won’t work for buy 2 get 1 free, etc. I want to be able to determine programmatically if any product has an auto-applied free product coupon. Is this possible? Thanks.

add_filter('woocommerce_coupon_is_valid_for_product', 'free_product_discount_coupon', 10, 4);

function free_product_discount_coupon($bool, $product, $coupon, $values) {

	// Get parent product id for variable products.
	// Required to retrieve custom meta data.

	$parent_id = $product->get_parent_id();

	// Create a parent product from the parent id or 
	// set $parent_product = $product if the product is the parent product.
	
	if ( $parent_id > 0 ) {
		$parent_product = wc_get_product( $parent_id );
	} else {
		$parent_product = $product;
	}

	// if coupon is a free product coupon, apply it.

	if ($coupon->get_meta('_wjecf_must_select_free_product') === 'yes') {
		return $bool;
	} else if ($parent_product->get_meta('hide_sub') == 1) {

		// Don't allow any other coupons to be applied 
		// to products with free product coupons (hide_sub = 1).

		return false;
	}

	return $bool;
	
}

[Soft79]

if $values['_wjecf_free_product_coupon'] is set, it’s a free product.

[anthonyceo]

I assume you meant the $coupon object? I don’t see that meta in the $values object.

The logical problem is that I need to know if the product has a free product coupon associated with it when it’s looping through other (non-free product) coupons. I want all other coupons to apply to everything else but the product with a free product. if I rely on _wjecf_free_product_coupon, no coupons other than the free product coupons will apply.

I can’t think of a straightforward way to do this except adding custom meta data like above. There must be another way.

[Soft79]

No, it must in the $values array. The value is set for every free cart item that was added by a coupon.

This works:

add_filter( 'woocommerce_coupon_is_valid_for_product', function( $valid, $product, $coupon, $values ) {
    if ( isset( $values['_wjecf_free_product_coupon'] ) ) error_log ( $product->get_id() . " is a free item" );
    return $valid;
}, 10, 4 );

[anthonyceo]

Very weird. I’m 100% sure it doesn’t have this on my end. Checked $values many times and doesn’t ever contain _wjecf_free_product_coupon. That code doesn’t work on my end with free products in cart.

However, I did create code that works. A lot more complex than I anticipated. And not very efficient. It was annoying. But hey, it works.

add_filter('woocommerce_coupon_is_valid_for_product', 'coupon_is_valid_for_free_product', 10, 4);

function coupon_is_valid_for_free_product($bool, $product, $coupon, $values) {

	// if coupon is a free product coupon, apply it.

	if ($coupon->get_meta('_wjecf_must_select_free_product') === 'yes') {
		return $bool;
	}

	// Get parent of product

	$parent_id = $product->get_parent_id();
	if ( $parent_id > 0 ) {
		$parent_product = wc_get_product( $parent_id );
	} else {
		$parent_product = $product;
	}

	// Get children ids of product

	$children = $parent_product->get_children();
	if (empty($children)) {
		$children[] = $product->id;
	}

	// get cart coupons
	
	$all_coupons = WC()->cart->get_coupons();

	// loop through cart coupons and don't apply non-free product coupons to free products
	foreach ($all_coupons as $c) {
		$product_ids = explode(',', $c->get_meta('_wjecf_free_product_ids'));
		foreach ($children as $id) {
			// If the current product id is in this free product cart coupon, don't apply coupon
			if (in_array($id, $product_ids)) {
				return false;
			}
		}
	}

	return $bool;
	
}

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