<node name="test_exists" channel="inline" format="access/indicate-exists" model="">
    <node name="result" channel="inline" format="text/cybol-path" model="#flag"/>
    <node name="part" channel="inline" format="text/cybol-path" model="#number"/>
</node>

<!-- Verify existence of given url path. -->
<node name="test_query" channel="inline" format="access/indicate-exists" model="">
    <node name="result" channel="inline" format="text/cybol-path" model=".var.query_exists"/>
    <node name="part" channel="inline" format="text/cybol-path" model=".var.request:uri:query"/>
</node>
<node name="evaluate_query" channel="inline" format="flow/branch" model="">
    <node name="criterion" channel="inline" format="text/cybol-path" model=".var.query_exists"/>
    <node name="true" channel="inline" format="text/cybol-path" model=".logic.evaluate_query"/>
    <!--
        CAUTION! Sending a response is important, even if the query was empty or not understood,
        since some browsers request a "/favicon.ico" or other things and if no response was sent,
        the browser would wait forever and block requests from other clients.
    -->
    <node name="false" channel="inline" format="text/cybol-path" model=".logic.send.empty_message"/>
</node>