Validate the options form.
Overrides PluginBase::validateOptionsForm
public function validateOptionsForm(&$form, &$form_state) {
$custom_fields = array(
'output_lifespan',
'results_lifespan',
);
foreach ($custom_fields as $field) {
if ($form_state['values']['cache_options'][$field] == 'custom' && !is_numeric($form_state['values']['cache_options'][$field . '_custom'])) {
form_error($form[$field . '_custom'], t('Custom time values must be numeric.'));
}
}
}