Form validation handler for filter_admin_format_form().
filter_admin_format_form_submit()
function filter_admin_format_form_validate($form, &$form_state) {
$format_format = trim($form_state['values']['format']);
$format_name = trim($form_state['values']['name']);
// Ensure that the values to be saved later are exactly the ones validated.
form_set_value($form['format'], $format_format, $form_state);
form_set_value($form['name'], $format_name, $form_state);
$result = db_query("SELECT format FROM {filter_format} WHERE name = :name AND format <> :format", array(
':name' => $format_name,
':format' => $format_format,
))
->fetchField();
if ($result) {
form_set_error('name', t('Text format names must be unique. A format named %name already exists.', array(
'%name' => $format_name,
)));
}
}