Allow only one item in cart from defined product categories in Woocommerce

Question

In Woocommerce, I found a bit of code that restricts a users purchase to one per category for category a or b. So currently the user could purchase 2 items 1 from cat a and 1 from cat b. I would like to limit the user to only one product from category a or b. The code I am working with is below, thanks in advance.

add_filter( 'woocommerce_add_to_cart_validation', 'allowed_quantity_per_category_in_the_cart', 10, 2 );function allowed_quantity_per_category_in_the_cart( $passed, $product_id) {

$max_num_products = 1;// change the maximum allowed in the cart
$running_qty = 0;

$restricted_product_cats = array();

//Restrict particular category/categories by category slug
$restricted_product_cats[] = 'cat-a, cat-b';


// Getting the current product category slugs in an array
$product_cats_object = get_the_terms( $product_id, 'product_cat' );
foreach($product_cats_object as $obj_prod_cat) $current_product_cats[]=$obj_prod_cat->slug;


// Iterating through each cart item
foreach (WC()->cart->get_cart() as $cart_item_key=>$cart_item ){

    // Restrict $max_num_products from each category
    if( has_term( $current_product_cats, 'product_cat', $cart_item['product_id'] )) {

    // Restrict $max_num_products from restricted product categories
    //if( array_intersect($restricted_product_cats, $current_product_cats) && has_term( $restricted_product_cats, 'product_cat', $cart_item['product_id'] )) {

        // count(selected category) quantity
        $running_qty += (int) $cart_item['quantity'];

        // More than allowed products in the cart is not allowed
        if( $running_qty >= $max_num_products ) {
            wc_add_notice( sprintf( 'Only %s '.($max_num_products>1?'products from this category are':'product from this category is').' allowed in the cart.',  $max_num_products ), 'error' );
            $passed = false; // don't add the new product to the cart
            // We stop the loop
            break;
        }

    }
}
return $passed;}

Answer 1

Try this (but it doesn't handle quantities as is not clear and much more complicated, because in cart page they can be altered) :

add_filter( 'woocommerce_add_to_cart_validation', 'limit_cart_items_from_category', 10, 3 );
function limit_cart_items_from_category ( $passed, $product_id, $quantity )
{
    // Accept when cart is empty
    if( WC()->cart->is_empty() ) return $passed;

    // HERE your product categories in this array (can be names, slugs or Ids)
    $categories = array('T-shirts', 'Hoodies');
    $found = $current = false;

    // Check the current product
    if( has_term( $categories, 'product_cat', $product_id ) ){
        $current = true;
    }

    // Loop through cart items checking for product categories
    foreach ( WC()->cart->get_cart() as $cart_item ){
        if( has_term( $categories, 'product_cat', $cart_item['product_id'] ) ) {
            $found = true;
            break; // stop the loop.
        }
    }

    // Current product and a cart item match with defined product categories
    if( $found && $current ){
        $passed = false;
        $cats_str = implode('" and "', $categories );
        wc_add_notice( sprintf( __('Only one item is allowed from "%s" categories…', 'woocommerce' ), $cats_str ), 'error' );
    }
    return $passed;
}

Code goes in function.php file of your active child theme (or active theme). Tested and work.

Answer 2

Thank You For your Code I modified this code and make my customized code. when customer add to cart the product from defined category, after that they didnt allow to cart other category product. you can set the maximum number of product easily by just changing the number. Thank You once again.

add_filter( 'woocommerce_add_to_cart_validation', 'limit_cart_items_from_category', 10, 3 );
function limit_cart_items_from_category ( $passed, $product_id, $quantity )
{
    // change the number for maximum product allowed in the cart
    $max_num_products = 5; // Here change the number for maximum allowed product in the cart
    // Accept when cart is empty
    if( WC()->cart->is_empty() ) return $passed;
    

    // HERE your product categories in this array (can be names, slugs or Ids)
    $categories = array('Sea-Food-Chaasum');
    $found = $current = false;

    // Check the current product
    if( has_term( $categories, 'product_cat', $product_id ) ){
        $current = true;
    }
    
    

    // Loop through cart items checking for product categories
    foreach ( WC()->cart->get_cart() as $cart_item ){
        if( has_term( $categories, 'product_cat', $cart_item['product_id'] ) ) {
            $found = true;
            $current = true;
            break; // stop the loop.
        }
    }
    
    
    // count(selected category) quantity
        $running_qty += (int) $cart_item['quantity'];

        // More than allowed products in the cart is not allowed
        if( $running_qty >= $max_num_products )
            

    // Current product and a cart item match with defined product categories
    if( $found && $current ){
        $passed = false;
        $cats_str = implode('" and "', $categories );
        wc_add_notice( sprintf( __('Only one item is allowed from "%s" categories…', 'woocommerce' ), $cats_str ), 'error' );
    }
    return $passed;
}