Update an associatvie array attached to an object by one of it's keys.

gistfile1.php

<?php
define('LANGUAGE_NONE', 'und');
/**
 * Update an associatvie array attached to an object by one of it's keys.
 *
 * @param $object object to work on
 * @param string $field attribute used of object
 * @param string $key key to be used of value array
 * @param array $value
 * @param string $lang
 * @param int $limit
 *  if 0 no limit will be applied.
 * @param $insert if true and no value is found, insert the value
 * @return count of updated values
 */
function _update_array_value($object, $field, $key, $value, $lang = LANGUAGE_NONE, $limit = 1, $insert = FALSE) {
  $count = 0;
  foreach ($object->{$field}[$lang] as &$sub) {
    if (isset($sub[$key]) && $sub[$key] == $value[$key]) {
      $sub = $value;
      $count++;
      if ($limit > 0 && $count >= $limit) {
        return $count;
      }
    }
  }
  if ($insert) {
    $object->{$field}[$lang][] = $value;
  }
  return $count;
}