gistfile1.txt

<?php

/**
 * @file
 * Custom views handler definition.
 *
 * Place this code in
 * /sites/all/[custom_module_name]/includes/views_handler_total_discounted_field.inc
 */

/**
 * Custom handler class.
 *
 * @ingroup views_field_handlers
 */
class views_handler_payable_to_designer_field extends views_handler_field {

  /**
   * {@inheritdoc}
   *
   * Perform any database or cache data retrieval here. In this example there is
   * none.
   */
  function query() {}

  /**
   * {@inheritdoc}
   *
   * Modify any end user views settings here. Debug $options to view the field
   * settings you can change.
   */
  function option_definition() {
    $options = parent::option_definition();
    return $options;
  }

  /**
   * {@inheritdoc}
   *
   * Make changes to the field settings form seen by the end user when adding
   * your field.
   */
  function options_form(&$form, &$form_state) {
    parent::options_form($form, $form_state);
  }

  /**
   * Render callback handler.
   *
   * Return the markup that will appear in the rendered field.
   */
  function render($values) {

    // get the price compoment
    $price_compoments = 
    $values->_field_data['commerce_line_item_field_data_commerce_line_items_line_item_']['entity']->commerce_total['und'][0]['data']['components'];
    
    // get the currency used
    $currency = _calculate_final_currency($price_compoments);

    // get the discount type used
    $discount_type = _calculate_discount_type($price_compoments);

    // get line item total price
    $item_total = _item_total(
      $values->_field_data['commerce_product_field_data_commerce_product_product_id']['entity']->commerce_price[und][0][amount], 
      $values->commerce_line_item_field_data_commerce_line_items_quantity
    );

    // get designer's country term id
    $designer_country_term_id = $values->_field_data['node_users_nid']['entity']->field_designer_country[und][0]['tid'];

    // get designer's vat number
    $designer_vat_number = $values->_field_data['node_users_nid']['entity']->field_designer_company_vat[und][0]['value'];
    
    // calculate the percentage that needs to be applied to this line item
    $percentage = _get_percentage_applied_to_line_item($designer_country_term_id,$designer_vat_number);
    
    if ($item_total) 
    {
      // calculate and return the final amount payable to designer
      return _calculate_payable_to_designer($item_total, $percentage, $line_item_id, $order_id,$currency);
    }
  }
}