php wordpress woocommerce cart hook-woocommerce

Add or remove a free product based on WooCommerce cart total and month range

I am on a project, which needs to add to cart a free item on particular promotional month. Therefore, I need to make the product value 0.00 and add it automatically to cart in a particular promotional month. So far, I have added the product automatically when the add to cart total reaches certain amount

/*
 * Automatically adding the product to the cart when cart total amount reach to $500.
 */

function aapc_add_product_to_cart() {
    global $woocommerce;
    
    $cart_total = 500;  

    if ( $woocommerce->cart->total >= $cart_total ) {
        if ( ! is_admin() ) {
            $free_product_id = 12989;  // Product Id of the free product which will get added to cart
            $found      = false;

            //check if product already in cart
            if ( sizeof( WC()->cart->get_cart() ) > 0 ) {
                foreach ( WC()->cart->get_cart() as $cart_item_key => $values ) {
                    $_product = $values['data'];
                    if ( $_product->get_id() == $free_product_id )
                        $found = true;                  
                }
                // if product not found, add it
                if ( ! $found )
                    WC()->cart->add_to_cart( $free_product_id );
            } else {
                // if no products in cart, add it
                WC()->cart->add_to_cart( $free_product_id );
            }        
        }
    }        
}

add_action( 'template_redirect', 'aapc_add_product_to_cart' );
...

Solution

Try the following instead (that handle dynamic changes in cart page and also a month range).

Note: the total amount for the threshold can be only the cart items total.

The code:

function is_free_product_allowed_for_month() {
    // Define allowed months in the array (values from 1 to 12)
    $allowed_months   = array('3', '7', '8');

    return in_array( date('n'), $allowed_months );
}


add_action( 'woocommerce_before_calculate_totals', 'add_remove_free_product' );
function add_remove_free_product( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Check if we are in an allowed month
    if ( ! is_free_product_allowed_for_month() )
        return;

    $free_product_id  = 339; // ID of the free product
    $threshold_amount = 200; // The threshold amount for cart subtotal
    $cart_items_total = 0; // Initializing

    // Loop through cart items
    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ){
        // Check if the free product is in cart
        if ( in_array( $free_product_id, array( $cart_item['product_id'], $cart_item['variation_id'] ) ) ) {
            $cart_item['data']->set_price(0); // Set price to Zero
            $free_item_key = $cart_item_key;

        }
        // Get cart subtotal incl. tax from items (with discounts if any)
        $cart_items_total += $cart_item['line_total'] + $cart_item['line_tax'];
    }

    // If Cart total is up to the defined amount and if the free products is not in cart, we add it.
    if ( $cart_items_total >= $threshold_amount && ! isset($free_item_key) ) {
        $cart->add_to_cart( $free_product_id );
    }
    // If cart total is below the defined amount and free product is in cart, we remove it.
    elseif ( $cart_items_total < $threshold_amount && isset($free_item_key) ) {
        $cart->remove_cart_item( $free_item_key );
    }
}


// For minicart displayed free product price
add_filter( 'woocommerce_cart_item_price', 'free_product_cart_item_price', 10, 3 );
function free_product_cart_item_price( $price_html, $cart_item, $cart_item_key ) {
    // Check if we are in an allowed month
    if ( ! is_free_product_allowed_for_month() )
        return $price_html;

    $free_product_id  = 339; // ID of the free product

    if ( in_array( $free_product_id, array( $cart_item['product_id'], $cart_item['variation_id'] ) ) ) {
        return wc_price( 0 );
    }
    return $price_html;
}

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