woocommerce_cart_item_product_id │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_cart_item_product_id', 'wp_kama_woocommerce_cart_item_product_id_filter', 10, 3 );

/**
 * Function for `woocommerce_cart_item_product_id` filter-hook.
 * 
 * @param  $cart_item_product_id 
 * @param  $cart_item            
 * @param  $cart_item_key        
 *
 * @return 
 */
function wp_kama_woocommerce_cart_item_product_id_filter( $cart_item_product_id, $cart_item, $cart_item_key ){

	// filter...
	return $cart_item_product_id;
}

$cart_item_product_id

-

$cart_item

-

$cart_item_key

-

Where the hook is called

$product_id = apply_filters( 'woocommerce_cart_item_product_id', $cart_item['product_id'], $cart_item, $cart_item_key );

$product_id = apply_filters( 'woocommerce_cart_item_product_id', $cart_item['product_id'], $cart_item, $cart_item_key );

Where the hook is used in WooCommerce