Drupal Commerce Rules: Loop through Commerce Line Items

commerce_rules_line_item_loop.php

<?php
// Use the code inside rule conditions with a Custom PHP code
// FIELD_MACHINE_NAME example: field_product_free_shipping
global $user;
$commerce_order = commerce_cart_order_load($user->uid);
$line_items = $commerce_order->commerce_line_items['und'];
foreach ($line_items as $lid) {
   $line_item = commerce_line_item_load($lid['line_item_id']);
	if ( isset($line_item->commerce_product)) {
       $pid = $line_item->commerce_product['und'][0]['product_id'];
       $product =  commerce_product_load($pid);
       $FIELD_MACHINE_NAME = render($product->FIELD_MACHINE_NAME['und'][0]['value']);
           if ($FIELD_MACHINE_NAME == '1') {
             return TRUE;
           }
	}
}
return FALSE;