Minimum cart item quantity for specific product categories in WooCommerce

Question

In WooCommerce, I need to set up a minimum quantity for each item of a product category. I searched the forum and found some code that works fine except it only counts the Q

Answer 1

Since WooCommerce 3, your actual code is outdated and not convenient… There is multiple ways:

1). The best way: Set up the minimum quantity at product level (for a product category):

// On single product pages
add_filter( 'woocommerce_quantity_input_args', 'min_qty_filter_callback', 20, 2 );
function min_qty_filter_callback( $args, $product ) {
    $categories = array('Noten'); // The targeted product category(ies)
    $min_qty    = 5; // The minimum product quantity

    $product_id = $product->is_type('variation') ? $product->get_parent_id() : $product->get_id();

    if( has_term( $categories, 'product_cat', $product_id ) ){
        $args['min_value'] = $min_qty;
    }
    return $args;
}

// On shop and archives pages
add_filter( 'woocommerce_loop_add_to_cart_args', 'min_qty_loop_add_to_cart_args', 10, 2 );
function min_qty_loop_add_to_cart_args( $args, $product ) {
    $categories = array('Noten'); // The targeted product category
    $min_qty    = 5; // The minimum product quantity

    $product_id = $product->get_id();

    if( has_term( $categories, 'product_cat', $product_id ) ){
        $args['quantity'] = $min_qty;
    }
    return $args;
}

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

2). Alternative way: Checking cart items and displaying an error message (similar to your code):

add_action( 'woocommerce_check_cart_items', 'wc_min_item_required_qty' );
function wc_min_item_required_qty() {
    $categories    = array('Noten'); // The targeted product category
    $min_item_qty  = 5; // Minimum Qty required (for each item)
    $display_error = false; // Initializing

    // Loop through cart items
    foreach(WC()->cart->get_cart() as $cart_item ) {
        $item_quantity = $cart_item['quantity']; // Cart item quantity
        $product_id    = $cart_item['product_id']; // The product ID

        // For cart items remaining to "Noten" producct category
        if( has_term( $categories, 'product_cat', $product_id ) && $item_quantity < $min_item_qty ) {
            wc_clear_notices(); // Clear all other notices

            // Add an error notice (and avoid checkout).
            wc_add_notice( sprintf( 'Bitte beachte die Mindestbestellmenge. Du brauchst mindestens %s Notenexemplare pro Arrangement. Aktuell hast du %s Stück in deinem Warenkorb.', $min_item_qty , $item_quantity ), 'error' );
            break; // Stop the loop
        }
    }
}

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

---

To make it work for parent product category too, you will also add this custom function:

// Custom conditional function that handle parent product categories too
function has_product_categories( $categories, $product_id = 0 ) {
     // Initializing
    $parent_term_ids = $categories_ids = array();
    $taxonomy        = 'product_cat';

    if( is_string( $categories ) ) {
        $categories = (array) $categories;
    }
    
    $product_id = $product_id > 0 ? $product_id : get_the_id();

    // Convert categories term names and slugs to categories term ids
    foreach ( $categories as $category ){
        if( is_numeric( $category ) ) {
            $categories_ids[] = (int) $category;
        } elseif ( term_exists( sanitize_title( $category ), $taxonomy ) ) {
            $categories_ids[] = get_term_by( 'slug', sanitize_title( $category ), $taxonomy )->term_id;
        }
    }

    // Loop through the current product category terms to get only parent main category term
    foreach( get_the_terms( $product_id, $taxonomy ) as $term ){
        if( $term->parent > 0 ){
            $parent_term_ids[] = $term->parent; // Set the parent product category
            $parent_term_ids[] = $term->term_id; // (and the child)
        } else {
            $parent_term_ids[] = $term->term_id; // It is the Main category term and we set it.
        }
    }
    return array_intersect( $categories_ids, array_unique($parent_term_ids) ) ? true : false;
}

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

Then in the existing code, you will replace:

has_term( $category, 'product_cat', $product_id )

by

has_product_categories( $category, $product_id )

That will allow you to handle parent product categories too.

Answer 2

To make it work for a certain product category item counts in total use this code instead:

add_action( 'woocommerce_check_cart_items', 'wc_min_item_required_qty' );
function wc_min_item_required_qty() {
    $categories    = '30'; // The targeted product category slug or ID
    $max_item_qty  = 10; // Minimum Qty required (for each item)
    $display_error = false; // Initializing

    // Loop through cart items
    foreach(WC()->cart->get_cart() as $cart_item ) {
        
        $product_id    = $cart_item['product_id']; // The product ID
        
    if( has_term( $categories, 'product_cat', $product_id )) {
        $item_quantity += $cart_item['quantity']; // Cart item quantity
    }
        // For cart items remaining to "Pizza" product category
        if( has_term( $categories, 'product_cat', $product_id ) && $item_quantity > $max_item_qty ) {
            
            wc_clear_notices(); // Clear all other notices
            
            // Add an error notice (and avoid checkout).
            wc_add_notice( sprintf( 'We can only take orders of up to 10 burgers per customer', $max_item_qty , $item_quantity ), 'error' );
            break; // Stop the loop
        }
    }
}