Allow cart item quantity update for only one product category in Woocommerce

Question

I am trying to disable quantity changes in the Woocommerce cart to every product except a single category.

I have tried a custom function to do this but it disables it for all items. Looking to only allow one category product quantity to be changed. I have used this code to disable it on all products so far:

add_filter( 'woocommerce_cart_item_quantity', 'wc_cart_item_quantity', 10, 3 );
function wc_cart_item_quantity( $product_quantity, $cart_item_key, $cart_item 
){
    if( is_cart() ){
        $product_quantity = sprintf( '%2$s <input type="hidden" 
name="cart[%1$s][qty]" value="%2$s" />', $cart_item_key,             
$cart_item['quantity'] );
    }
    return $product_quantity;
}

Answer 1

You can use has_tem() conditional function to target only specific product category(ies) set for your cart items like:

add_filter( 'woocommerce_cart_item_quantity', 'wc_cart_item_quantity', 10, 3 );
function wc_cart_item_quantity( $product_quantity, $cart_item_key, $cart_item ){
    $categories = array('disc'); // Define your allowed product category(ies)

    if( is_cart() && ! has_term( $categories, $taxonomy, $cart_item['product_id'] ){
        $product_quantity = sprintf( '%2$s <input type="hidden" 
name="cart[%1$s][qty]" value="%2$s" />', $cart_item_key,             
$cart_item['quantity'] );
    }
    return $product_quantity;
}

Code goes in functions.php file of your active child theme (or active theme). It should work.