date_id
 *    If set, this will show only an individual date on a field with
 *    multiple dates. The value should be a string that contains
 *    the following values, separated with periods:
 *    - module name of the module adding the item
 *    - node nid
 *    - field name
 *    - delta value of the field to be displayed
 *    - other information the module's custom theme might need
 *
 *    Used by the calendar module and available for other uses.
 *    example: 'date.217.field_date.3.test'
 *
 *  $entity->date_repeat_show
 *    If true, tells the theme to show all the computed values of a repeating
 *    date. If not true or not set, only the start date and the repeat rule
 *    will be displayed.
 *
 *  $dates['format']
 *    The format string used on these dates
 *  $dates['value']['local']['object']
 *    The local date object for the Start date
 *  $dates['value2']['local']['object']
 *    The local date object for the End date
 *  $dates['value']['local']['datetime']
 *    The datetime value of the Start date database (GMT) value
 *  $dates['value2']['local']['datetime']
 *    The datetime value of the End date database (GMT) value
 *  $dates['value']['formatted']
 *    Formatted Start date, i.e. 'February 15, 2007 2:00 pm';
 *  $dates['value']['formatted_date']
 *    Only the date part of the formatted Start date
 *  $dates['value']['formatted_time']
 *    Only the time part of the formatted Start date
 *  $dates['value2']['formatted']
 *    Formatted End date, i.e. 'February 15, 2007 6:00 pm';
 *  $dates['value2']['formatted_date']
 *    Only the date part of the formatted End date
 *  $dates['value2']['formatted_time']
 *    Only the time part of the formatted End date
 */
function theme_date_display_combination($variables) {
  static $repeating_ids = array();
  $entity_type = $variables['entity_type'];
  $entity      = $variables['entity'];
  $field       = $variables['field'];
  $instance    = $variables['instance'];
  $langcode    = $variables['langcode'];
  $item        = $variables['item'];
  $delta       = $variables['delta'];
  $display     = $variables['display'];
  $field_name  = $field['field_name'];
  $formatter   = $display['type'];
  $options     = $display['settings'];
  $dates       = $variables['dates'];
  $attributes  = $variables['attributes'];
  $rdf_mapping = $variables['rdf_mapping'];
  $add_rdf     = $variables['add_rdf'];
  $microdata   = $variables['microdata'];
  $add_microdata = $variables['add_microdata'];
  $precision   = date_granularity_precision($field['settings']['granularity']);
  $output = '';
  // If date_id is set for this field and delta doesn't match, don't display it.
  if (!empty($entity->date_id)) {
    foreach ((array) $entity->date_id as $key => $id) {
      list($module, $nid, $field_name, $item_delta, $other) = explode('.', $id . '.');
      if ($field_name == $field['field_name'] && isset($delta) && $item_delta != $delta) {
        return $output;
      }
    }
  }
  // Check the formatter settings to see if the repeat rule should be displayed.
  // Show it only with the first multiple value date.
  list($id) = entity_extract_ids($entity_type, $entity);
  if (!in_array($id, $repeating_ids) && module_exists('date_repeat_field') && !empty($item['rrule']) && $options['show_repeat_rule'] == 'show') {
    $repeat_vars = array(
      'field' => $field,
      'item' => $item,
      'entity_type' => $entity_type,
      'entity' => $entity,
    );
    $output .= theme('date_repeat_display', $repeat_vars);
    $repeating_ids[] = $id;
  }
  // If this is a full node or a pseudo node created by grouping multiple
  // values, see exactly which values are supposed to be visible.
  if (isset($entity->$field_name)) {
    $entity = date_prepare_entity($formatter, $entity_type, $entity, $field, $instance, $langcode, $item, $display);
    // Did the current value get removed by formatter settings?
    if (empty($entity->{$field_name}[$langcode][$delta])) {
      return $output;
    }
    // Adjust the $element values to match the changes.
    $element['#entity'] = $entity;
  }
  switch ($options['fromto']) {
    case 'value':
      $date1 = $dates['value']['formatted'];
      $date2 = $date1;
      break;
    case 'value2':
      $date2 = $dates['value2']['formatted'];
      $date1 = $date2;
      break;
    default:
      $date1 = $dates['value']['formatted'];
      $date2 = $dates['value2']['formatted'];
      break;
  }
  // Pull the timezone, if any, out of the formatted result and tack it back on
  // at the end, if it is in the current formatted date.
  $timezone = $dates['value']['formatted_timezone'];
  if ($timezone) {
    $timezone = ' ' . $timezone;
  }
  $date1 = str_replace($timezone, '', $date1);
  $date2 = str_replace($timezone, '', $date2);
  $time1 = preg_replace('`^([\(\[])`', '', $dates['value']['formatted_time']);
  $time1 = preg_replace('([\)\]]$)', '', $time1);
  $time2 = preg_replace('`^([\(\[])`', '', $dates['value2']['formatted_time']);
  $time2 = preg_replace('([\)\]]$)', '', $time2);
  // A date with a granularity of 'hour' has a time string that is an integer
  // value. We can't use that to replace time strings in formatted dates.
  $has_time_string = date_has_time($field['settings']['granularity']);
  if ($precision == 'hour') {
    $has_time_string = FALSE;
  }
  // No date values, display nothing.
  if (empty($date1) && empty($date2)) {
    $output .= '';
  }
  // Start and End dates match or there is no End date, display a complete
  // single date.
  elseif ($date1 == $date2 || empty($date2)) {
    $output .= theme('date_display_single', array(
      'date' => $date1,
      'timezone' => $timezone,
      'attributes' => $attributes,
      'rdf_mapping' => $rdf_mapping,
      'add_rdf' => $add_rdf,
      'microdata' => $microdata,
      'add_microdata' => $add_microdata,
      'dates' => $dates,
    ));
  }
  // Same day, different times, don't repeat the date but show both Start and
  // End times. We can NOT do this if the replacement value is an integer
  // instead of a time string.
  elseif ($has_time_string && $dates['value']['formatted_date'] == $dates['value2']['formatted_date']) {
    // Replace the original time with the start/end time in the formatted start
    // date. Make sure that parentheses or brackets wrapping the time will be
    // retained in the final result.
    $time = theme('date_display_range', array(
      'date1' => $time1,
      'date2' => $time2,
      'timezone' => $timezone,
      'attributes' => $attributes,
      'rdf_mapping' => $rdf_mapping,
      'add_rdf' => $add_rdf,
      'microdata' => $microdata,
      'add_microdata' => $add_microdata,
      'dates' => $dates,
    ));
    $replaced = str_replace($time1, $time, $date1);
    $output .= theme('date_display_single', array(
      'date' => $replaced,
      'timezone' => $timezone,
      'attributes' => array(),
      'rdf_mapping' => array(),
      'add_rdf' => FALSE,
      'dates' => $dates,
    ));
  }
  // Different days, display both in their entirety.
  else {
    $output .= theme('date_display_range', array(
      'date1' => $date1,
      'date2' => $date2,
      'timezone' => $timezone,
      'attributes' => $attributes,
      'rdf_mapping' => $rdf_mapping,
      'add_rdf' => $add_rdf,
      'microdata' => $microdata,
      'add_microdata' => $add_microdata,
      'dates' => $dates,
    ));
  }
  return $output;
}
/**
 * Template preprocess function for displaying a single date.
 */
function template_preprocess_date_display_single(&$variables) {
  if ($variables['add_rdf'] || !empty($variables['add_microdata'])) {
    // Pass along the rdf mapping for this field, if any. Add some default rdf
    // attributes that will be used if not overridden by attributes passed in.
    $rdf_mapping = $variables['rdf_mapping'];
    $base_attributes = array(
      'property' => array('dc:date'),
      'datatype' => 'xsd:dateTime',
      'content' => $variables['dates']['value']['formatted_iso'],
    );
    $variables['attributes'] = $variables['attributes'] + $base_attributes;
  }
  // Pass along microdata attributes, or set display to false if none are set.
  if (!empty($variables['add_microdata'])) {
    // Because the Entity API integration for Date has a variable data
    // structure depending on whether there is an end value, the attributes
    // could be attached to the field or to the value property.
    if(!empty($variables['microdata']['#attributes']['itemprop'])) {
      $variables['microdata']['value']['#attributes'] = $variables['microdata']['#attributes'];
    }
    // Add the machine readable time using the content attribute.
    if(!empty($variables['microdata']['value']['#attributes'])) {
      $variables['microdata']['value']['#attributes']['content'] = $variables['dates']['value']['formatted_iso'];
    }
    else {
      $variables['add_microdata'] = FALSE;
    }
  }
}
/**
 * Returns HTML for a date element formatted as a single date.
 */
function theme_date_display_single($variables) {
  $date = $variables['date'];
  $timezone = $variables['timezone'];
  $attributes = $variables['attributes'];
  // Wrap the result with the attributes.
  $output = '' . $date . $timezone . '';
  if (!empty($variables['add_microdata'])) {
    $output .= '';
  }
  return $output;
}
/**
 * Template preprocess function for displaying a range of dates.
 */
function template_preprocess_date_display_range(&$variables) {
  // Merge in the shared attributes for themes to use.
  $variables['attributes_start'] += $variables['attributes'];
  $variables['attributes_end'] += $variables['attributes'];
  if ($variables['add_rdf']) {
    // Pass along the rdf mapping for this field, if any. Add some default rdf
    // attributes that will be used if not overridden by attributes passed in.
    $dates = $variables['dates'];
    $base_attributes = array(
      'property' => array('dc:date'),
      'datatype' => 'xsd:dateTime',
      'content' => $dates['value']['formatted_iso'],
    );
    $variables['attributes_start'] += $base_attributes;
    $variables['attributes_end'] += $base_attributes;
    $variables['attributes_end']['content'] = $dates['value2']['formatted_iso'];
    foreach ($variables['attributes_end']['property'] as $delta => $property) {
      $variables['attributes_end']['property'][$delta] = str_replace('start', 'end', $property);
    }
  }
  // Pass along microdata attributes, or set display to false if none are set.
  if ($variables['add_microdata']) {
    if (!empty($variables['microdata']['value']['#attributes'])) {
      $variables['microdata']['value']['#attributes']['content'] = $variables['dates']['value']['formatted_iso'];
      $variables['microdata']['value2']['#attributes']['content'] = $variables['dates']['value2']['formatted_iso'];
    }
    else {
      $variables['add_microdata'] = FALSE;
    }
  }
}
/**
 * Returns HTML for a date element formatted as a range.
 */
function theme_date_display_range($variables) {
  $date1 = $variables['date1'];
  $date2 = $variables['date2'];
  $timezone = $variables['timezone'];
  $attributes_start = $variables['attributes_start'];
  $attributes_end = $variables['attributes_end'];
  $start_date = '' . $date1 . '';
  $end_date = '' . $date2 . $timezone . '';
  // If microdata attributes for the start date property have been passed in,
  // add the microdata in meta tags.
  if (!empty($variables['add_microdata'])) {
    $start_date .= '';
    $end_date .= '';
  }
  // Wrap the result with the attributes.
  return t('!start-date to !end-date', array(
    '!start-date' => $start_date,
    '!end-date' => $end_date,
  ));
}
/**
 * Returns HTML for a date element formatted as an interval.
 */
function theme_date_display_interval($variables) {
  $entity = $variables['entity'];
  $options = $variables['display']['settings'];
  $dates = $variables['dates'];
  $attributes = $variables['attributes'];
  // Get the formatter settings, either the default settings for this node type
  // or the View settings stored in $entity->date_info.
  if (!empty($entity->date_info) && !empty($entity->date_info->formatter_settings)) {
    $options = $entity->date_info->formatter_settings;
  }
  $time_ago_vars = array(
    'start_date' => $dates['value']['local']['object'],
    'end_date' => $dates['value2']['local']['object'],
    'interval' => $options['interval'],
    'interval_display' => $options['interval_display'],
  );
  if ($return = theme('date_time_ago', $time_ago_vars)) {
    return '$return";
  }
  else {
    return '';
  }
}
/**
 * Returns HTML for a start/end date combination on form.
 */
function theme_date_combo($variables) {
  $element = $variables['element'];
  $field = field_info_field($element['#field_name']);
  $instance = field_info_instance($element['#entity_type'], $element['#field_name'], $element['#bundle']);
  // Group start/end items together in fieldset.
  $fieldset = array(
    '#title' => field_filter_xss(t($element['#title'])) . ' ' . ($element['#delta'] > 0 ? intval($element['#delta'] + 1) : ''),
    '#value' => '',
    '#description' => !empty($element['#fieldset_description']) ? $element['#fieldset_description'] : '',
    '#attributes' => array(),
    '#children' => $element['#children'],
  );
  // Add marker to required date fields.
  if ($element['#required']) {
    $fieldset['#title'] .= " " . theme('form_required_marker');
  }
  return theme('fieldset', array('element' => $fieldset));
}
/**
 * Returns HTML for the text/select options for date parts in a table.
 */
function theme_date_text_parts($variables) {
  $element = $variables['element'];
  $rows = array();
  foreach (date_granularity_names() as $key => $part) {
    if ($element[$key]['#type'] == 'hidden') {
      $rows[] = drupal_render($element[$key]);
    }
    else {
      $rows[] = array($part, drupal_render($element[$key][0]), drupal_render($element[$key][1]));
    }
  }
  if ($element['year']['#type'] == 'hidden') {
    return implode($rows) . drupal_render_children($element);
  }
  else {
    $header = array(t('Date part'), t('Select list'), t('Text field'));
    return theme('table', array('header' => $header, 'rows' => $rows)) . drupal_render_children($element);
  }
}
/** @} End of addtogroup themeable */