save_alert_field.naml

<override_macro name="save_alert_field" requires="node,servlet">
    <n.if.null_to_true.alert_field.value>
        <then.topic_node.subscribe_visitor/>
        <else.topic_node.unsubscribe_visitor/>
    </n.if.null_to_true.alert_field.value>
</override_macro>