Contribution: New rule condition "Total product of type quantity comparison"

I have managed to create a new Rule condition called "Total product of type quantity comparison"

This condition is the same as the "Total product quantity comparison" but also takes a product type, and only counts items of that type.

Below are the condition declaration for hook_rules_condition_info() and the call back. It would be cool if they could be included as I think being able to get the quantity of a product type is particularly useful for things like shipping calculations and discounts.

  $conditions['commerce_order_compare_total_product_type_quantity'] = array(
    'label' => t('Total product of type quantity comparison'),
    'parameter' => array(
      'commerce_order' => array(
        'type' => 'commerce_order',
        'label' => t('Order'),
        'description' => t('The order whose product line item quantities should be totalled. If the specified order does not exist, the comparison will act as if it is against a quantity of 0.'),
      ),
      'product_type' => array(
        'type' => 'text',
        'label' => t('Product Type'),
        'description' => t('The type of the product to look for on the order.'),
        'options list' => 'commerce_product_type_options_list',
        'restriction' => 'input',
      ),
      'operator' => array(
        'type' => 'text',
        'label' => t('Operator'),
        'description' => t('The comparison operator to use against the total number of products on the order.'),
        'default value' => '>=',
        'options list' => 'commerce_numeric_comparison_operator_options_list',
        'restriction' => 'input',
      ),
      'value' => array(
        'type' => 'text',
        'label' => t('Quantity'),
        'default value' => 1,
        'description' => t('The value to compare against the total quantity of products on the order.'),
      ),
    ),
    'group' => t('Commerce Order'),
    'callbacks' => array(
      'execute' => 'commerce_order_rules_compare_total_product_type_quantity',
    ),
  );

/**
 * Condition callback: compares the total quantity of products of a specific type
 * against the specified quantity.
 */
function commerce_order_rules_compare_total_product_type_quantity($order, $product_type, $operator, $value) {
  $products = array($product_type => 0);

  // If we received an order, get the total quantity of products on it.
  if (!empty($order)) {
    $order_wrapper = entity_metadata_wrapper('commerce_order', $order);
  
    // Populate the array of the quantities of the products on the order.
    foreach ($order_wrapper->commerce_line_items as $delta => $line_item_wrapper) {
      if (in_array($line_item_wrapper->type->value(), commerce_product_line_item_types())) {
      	// Get the product
      	$product_wrapper = entity_metadata_wrapper('commerce_product', $line_item_wrapper->commerce_product->product_id->value());
        // Extract a product type and quantity from the line item.
        $line_item_product_type = $product_wrapper->type->value();
        $quantity = $line_item_wrapper->quantity->value();

        // Update the product's quantity value.
        if (empty($products[$line_item_product_type])) {
          $products[$line_item_product_type] = $quantity;
        }
        else {
          $products[$line_item_product_type] += $quantity;
        }
      }
    }
  }

  // Make a quantity comparison based on the operator.
  switch ($operator) {
    case '<':
      return $products[$product_type] < $value;
    case '<=':
      return $products[$product_type] <= $value;
    case '=':
      return $products[$product_type] == $value;
    case '>=':
      return $products[$product_type] >= $value;
    case '>':
      return $products[$product_type] > $value;
  }

  return FALSE;
}

Cheers,
Sam