'Display Value'
 *
 * It is possible to group options together; to do this, change the format of
 * $options to an associative array in which the keys are group labels, and the
 * values are associative arrays in the normal $options format.
 */
define('options', '_options');
/**
 * Keyword: extra
 * Used: select boxes.
 * Description: Additional HTML to inject into the select element tag.
 */
define('extra', '_extra');
/**
 * Keyword: multiple
 * Used: select boxes.
 * Description: Wether the user may select more than one item.
 */
define('multiple', '_multiple');
/**
 * Keyword: button_type 
 * Used: buttons.
 * Description: The type of button to display (cancel or submit) 
 */
define('button_type', '_button_type');
/**
 * Keyword: error 
 * Used: All visible form elements.
 * Description: Wether or not a form element has been flagged as having an error.
 */
define('error', '_error');
/**
 * Keyword: prefix
 * Used: markup element.
 * Description: Text to include before the value and children properties.
 */
define('prefix', '_prefix');
/**
 * Keyword: suffix
 * Used: markup element.
 * Description: Text to include after the value and children properties.
 */
define('suffix', '_suffix');
/**
 * Keyword: error 
 * Used: weight form element.
 * Description: Number of weights to have selectable.
 */
define('delta', '_delta');
/** 
 * Multiple elements. For use in the poll module, and for file uploads.
 */
/**
 * Keyword : process
 * Used : By any element, used to modify a form element.
 */
define('process', '_process');
/**
 * Keyword: multiple 
 */
define('multiple', '_multiple');
/**
 * Keyword: min 
 */
define('min', '_min');
/**
 * Keyword: max
 */
define('max', '_max');
/**
 * Keyword: increment
 */
define('increment', '_increment');
/**
 * Check if the key is a property.
 */
function element_property($key) {
 return (substr($key, 0, 1) == '_');
}
/**
 * Check if the key is a child.
 */
function element_child($key) {
  return (substr($key, 0, 1) != '_');
}
/**
 * Processes a form array, and produces the HTML output of a form.
 * If there is input in the $_POST['edit'] variable, this function
 * will attempt to validate it, using drupal_validate_form, 
 * and then execute the form using drupal_execute_form.
 *
 * @param $form_id
 *   A unique string identifying the form. Allows each form to be themed.
 * @param $form
 *   An associative array containing the structure of the form.
 * @param $callback
 *   An optional callback that will be used in addition to the form_id.
 *  
 */
function drupal_get_form($form_id, &$form, $callback = NULL) {
  global $form_values;
  $form_values = array();
  if (!$form[built]) {
    $form = _form_builder($form);
  }
  // If the form validates, it will execute.
  drupal_execute_form($form_id, $form, $callback);
  // Set the form to markup, to allow children to be populated from a theme function.
  $form[type] = 'markup'; 
  if ($content = theme($form_id, $form)) {
    // form_id theme function successful. Form specific theme function.
    $form[children] = $content;
  }
  elseif ($content = theme($callback, $form)) {
    // callback theme function successful. This allows multiple forms to share one theme function.
    $form[children] = $content;
  }
 
  // Set up the form element.  
  $form[type] = 'form';
  $form[printed] = FALSE;
  $form[attributes]['class'] .= ' form-api';
  $form = array_merge(_element_info('form'), $form);
  return form_render($form);
}
function drupal_validate_form($form_id, &$form, $callback = NULL) {
  _form_validate($form);
  if (function_exists($form_id . '_validate')) {
    call_user_func($form_id . '_validate', $form_id, $form);
  }
  if (function_exists($callback . '_validate')) {
    call_user_func($callback . '_validate', $form_id, $form);
  }
}
function drupal_execute_form($form_id, $form, $callback = NULL) {
  if (!empty($_POST['edit'])) {
    drupal_validate_form($form_id, $form, $callback);
    if (!form_get_errors()) {
      if (function_exists($form_id . '_execute')) {
        call_user_func($form_id . '_execute', $form_id, $form);
      }
      elseif (function_exists($callback . '_execute')) {
        call_user_func($callback . '_execute', $form_id, $form);
      }
    }
  }
}
function _form_validate(&$form) {
  // Recurse through all children.
  foreach ($elements as $key => $element) {
    if (element_child($key)) {
      _form_validate($element);
    }
  }
  /* Validate the current input */
  if (!$elements[validated] && $elements[input]) {
    if ($elements[required]) {
      if (!$elements[value]) {
        form_error($elements, t('%name field is required', array('%name' => $element[title])));
      }
      if ($elements[valid]) {
        if (is_array($elements[valid])) {
          foreach ($elements[valid] as $key => $valid) {
            $args = is_array($elements[validation_arguments][$key]) ? $elements[validation_arguments][$key] : array();
            if (function_exists('valid_' . $valid))  {
              call_user_func_array('valid_' . $valid, array_merge(array($elements), $args));
            } 
          } 
        }
        else {
          $args = is_array($elements[validation_arguments]) ? $elements[validation_arguments] : array();
          if (function_exists('valid_' . $elements[valid]))  {
            call_user_func_array('valid_' . $elements[valid], array_merge(array($elements), $args));
          } 
        }
      }
    }
    $elements[validated] = TRUE;
  } 
}
/**
 * Flag an element as having an error.
 */
function form_error(&$element, $message) {
  $element[error] = TRUE;
  $GLOBALS['form'][$element[name]] = $message;
  drupal_set_message($message, 'error');
}
/**
 * Adds some required properties to each form element, which are used internally in the form api.
 * This function also automatically assigns the value property from the $edit array, provided the
 * element doesn't already have an assigned value.
 */
function _form_builder($form, $parents = array(), $multiple = FALSE) {
  global $form_values;
  
  $form[parents] = ($form[parents]) ? $form[parents] : $parents;
  /* Use element defaults */
  if (!empty($form[type])) { 
    $form = array_merge(_element_info($form[type]), $form);
  }
  if ($form[input]) {
    $form[name] = ($form[name]) ? $form[name] : 'edit[' . implode('][', $form[parents]) . ']';
    $form[id] =  ($form[id]) ? $form[id] : 'edit-' . implode('-', $form[parents]);
    
    $edit = $_POST['edit'];
    $ref =& $form_values;
    foreach ($form[parents] as $parent) {
      $edit = $edit[$parent];
      $ref =& $ref[$parent];
    }
          
    $form[value] = ($form[value]) ? $form[value] : ($edit ? $edit : $form[default_value]);
    $ref = $form[value];
  }
  // Allow for elements to expand to multiple elements. Radios, checkboxes and files for instance.
  if (function_exists($form[process]) && !$form[processed]) {
    $form = call_user_func($form[process], $form);
    $form[processed] = TRUE;
  }
  // Recurse through all child elements.
  $count  = 0;
  foreach ($form as $key => $element) {
    if (element_child($key)) {
      # Assign a decimal placeholder weight, to preserve original array order
      $element[weight] = $element[weight] ? $element[weight] : $count/10;
      $form[$key] = _form_builder($element, array_merge($form[parents], array($key)));
      $count++;
    }
  }
  return $form;
}
/**
 * Renders a HTML form given an form tree.  Recursively iterates over each of 
 * each of the form elements generating HTML code.  This function is usually 
 * called from within a theme.  To render a form from within a module, use
 * drupal_get_form().
 *
 * @param $elements 
 *   The form tree describing the form.
 * @return
 *   The rendered HTML form.
 */
function form_render(&$elements) {
  $content = '';
  if (is_array($elements)) {
    uasort($elements, "_form_sort");
  }
  if (!$elements[children]) {
    foreach ($elements as $key => $element) {
      if (!element_property($key)) {
        $content .= form_render($element);
      }
    }
    if ($content) {
      $elements[children] = $content;
    }
  }
  /* Call the form element renderer */
  if (!$elements[printed]) { 
    $content = theme(($elements[type]) ? $elements[type]: 'markup', $elements);
    $elements[printed] = TRUE;
  } 
  return $content;
}
/**
 * Function used by uasort in form render to sort form via weight.
 */
function _form_sort($a, $b) {
  if ($a[weight] == $b[weight]) {
    return 0;
  }
  return ($a[weight] < $b[weight]) ? -1 : 1;
}
/**
 * Retrieve the default properties for the defined element type.
 */
function _element_info($type, $refresh = null) {
  static $cache;
  $basic_defaults = array(
    description => NULL,
    attributes => array(),
    required => FALSE
  );
  if ($refresh || !is_array($cache)) {
    $cache = array();
    foreach (module_implements('elements') as $module) {
      $elements = module_invoke($module, 'elements');
      if (is_array($elements)) {
        $cache = array_merge($cache, $elements);
      }
    }
    if (sizeof($cache)) {
      foreach ($cache as $element_type => $info) {
        $cache[$element_type] = array_merge($basic_defaults, $info);
      }
    }
  }
  return $cache[$type];
}
/**
 * Format a dropdown menu or scrolling selection box.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used : title, value, options, description, extra, multiple, required
 * @return
 *   A themed HTML string representing the form element.
 *
 * It is possible to group options together; to do this, change the format of
 * $options to an associative array in which the keys are group labels, and the
 * values are associative arrays in the normal $options format.
 */
function theme_select($element) {
  $select = '';
  foreach ($element[options] as $key => $choice) {
    if (is_array($choice)) {
      $select .= '';
    }
    else {
      $select .= '';
    }
  }
  return theme('form_element', $element[title], '', $element[description], $element[name], $element[required], _form_get_error($element[name]));
}
/**
 * Format a group of form items.
 *
 * @param $element
 *   An associative array containing the properties of the element.
 *   Properties used : attributes, title, description, children, collapsible, collapsed
 * @return
 *   A themed HTML string representing the form item group.
 */
function theme_fieldset($element) {
  if ($element[collapsible]) {
    drupal_add_js('misc/collapse.js');
    $element[attributes]['class'] .= ' collapsible';
    if ($element[collapsed]) {
     $element[attributes]['class'] .= ' collapsed';
    }
  }
  
  return '
"; print_r($value); print ""; } ?>