tag for the form field object. * @param mixed $value The form field value to validate. * @param string $group The field name group control value. This acts as as an array container for the field. * For example if the field has name="foo" and the group value is set to "bar" then the * full field name would end up being "bar[foo]". * @param JRegistry $input An optional JRegistry object with the entire data set to validate against the entire form. * @param JForm $form The form object for which the field is being tested. * * @return boolean True if the value is valid, false otherwise. * * @since 11.1 */ public function test(SimpleXMLElement $element, $value, $group = null, JRegistry $input = null, JForm $form = null) { // Get the database object and a new query object. $db = JFactory::getDbo(); $query = $db->getQuery(true); // Build the query. $query->select('COUNT(*)') ->from('#__users') ->where('username = ' . $db->quote($value)); // Get the extra field check attribute. $userId = ($form instanceof JForm) ? $form->getValue('id') : ''; $query->where($db->quoteName('id') . ' <> ' . (int) $userId); // Set and query the database. $db->setQuery($query); $duplicate = (bool) $db->loadResult(); if ($duplicate) { return false; } return true; } }