handlers/views_handler_argument_formula.inc

<?php
class views_handler_argument_formula extends views_handler_argument {
  var $formula = NULL;
  function construct() {
    parent::construct();

    if (!empty($this->definition['formula'])) {
      $this->formula = $this->definition['formula'];
    }
  }

  function get_formula() {
    return str_replace('***table***', $this->table_alias, $this->formula);
  }

  function summary_query() {
    $this->ensure_my_table();
    // Now that our table is secure, get our formula.
    $formula = $this->get_formula();

    // Add the field.
    $this->base_alias = $this->name_alias = $this->query->add_field(NULL, $formula, $this->field);
    $this->query->set_count_field(NULL, $formula, $this->field);

    return $this->summary_basics(FALSE);
  }

  function query($group_by = FALSE) {
    $this->ensure_my_table();
    // Now that our table is secure, get our formula.
    $placeholder = $this->placeholder();
    $formula = $this->get_formula() .' = ' . $placeholder;
    $placeholders = array(
      $placeholder => $this->argument,
    );
    $this->query->add_where(0, $formula, $placeholders, 'formula');
  }
}