Custom field default value functions

gistfile1.php

<?php

/**
 * Custom field default value function for entity reference fields.
 */
function entityreference_get_default_handler_value($entity_type, $entity, $field, $instance, $langcode) {
  if (!isset($instance['settings']['default_handler']) || !isset($instance['settings']['default_handler_settings'])) {
    return array();
  }

  // Merge the default handler settings back into the normal field settings for
  // the purpose of using the handler.
  $field['settings']['handler'] = $instance['settings']['default_handler'];
  $field['settings']['handler_settings'] = $instance['settings']['default_handler_settings'];

  $return = array();

  if ($handler = entityreference_get_selection_handler($field, $instance, $entity_type, $entity)) {
    $ids = array();
    $results = $handler->getReferencableEntities();
    foreach ($results as $bundle => $result_ids) {
      $ids = array_merge($ids, array_keys($result_ids));
    }
    $ids = array_unique($ids);
    foreach ($ids as $id) {
      $return[] = array('target_id' => $id);
    }
  }

  return $return;
}

/**
 * For a number field, use default value of maximum + 1.
 */
function number_integer_default_value_max_plus_one($entity_type, $entity, $field, $instance, $langcode) {
  if ($field['storage']['type'] == 'field_sql_storage') {
    $table = _field_sql_storage_tablename($field);
    $column = _field_sql_storage_columnname($field['field_name'], 'value');
    $query = db_select($table);
    $query->addExpression('MAX(' . $column . ')');
    $max = (int) $query->execute()->fetchField();
    return $max + 1;
  }
}