Posting plain text to ActiveMQ from WSO2 proxy - wso2

Question

I am new to the WSO2 and ActiveMQ, and I have been trying to achieve a seemingly simple message transformation, but without success.
I need to expose a web service on WSO2 which will take the value of only one particular input argument (out of three),
and forward that value as a plain text string on to the ActiveMQ queue. So, there is no backend service, no response to process,
only a simple one-way forwarding operation is required with value extraction and a transformation to plain text before posting to the queue.
I've been through the proxy samples and a lot of google-ing, yet, the most I have managed is to get that required value on the queue,
but as a POX, and that is not satisfactory.
Actually I have doubts whether WSO2 is capable of posting a plain text string at all,
and yet, there are articles where people swore that it can do almost anything imaginable, only they do not explain exactly how.
What I do is that I extract the required value "arg2" using the PayloadFactory mediator,
into an <xdr> element (because the PayloadFactory insists on either the XML or the JSON format, no plain text allowed).
Then I send that element to the queue. Question #1 is whether WSO2 can somehow convert that xml into plain text automatically?
Currently I think not.
So, before sending, I have tried many things to get that value out without any xml tags,
mostly using the Enrich mediator and even Javascript, but at one point or another, the thing would fail - either the WSO2 wouldn't let me define such mediation,
or it would simply not perform as expected/required, or fail at runtime.
The Enrich mediator is also not really clearly explained - what does "source" mean,
and what is the "target", with all those options - whatever options I chose, I've neever seen any change done to my message by the Enrich mediator.
What am I doing wrong, please? :)
Below is my current WSO2 proxy definition, which now contains pretty much everything I've compiled from the net so far,
but it still only posts the value format to the queue - so this is merely an illustration of what I've tried so far:
<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
name="VomsXdrPlain"
transports="http"
statistics="disable"
trace="enable"
startOnLoad="true">
<target>
<inSequence>
<!-- first, the extraction -->
<payloadFactory media-type="xml">
<format>
<xdr xmlns="">$1</xdr>
</format>
<args>
<arg xmlns:xsd="http://api.service.com/"
evaluator="xml"
expression="//xsd:arg2"/>
</args>
</payloadFactory>
<!-- the following was added out of desperation -->
<property name="OUT_ONLY" value="true"/>
<property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
<property name="FORCE_POST_PUT_NOBODY"
value="true"
scope="axis2"
type="BOOLEAN"/>
<!-- here the idea was to put the value into a property, so it might be used in the Enrich mediator -->
<property name="xdrTicket"
expression="//xdr/text()"
scope="default"
type="STRING"/>
<!-- how to use the Enrich mediator properly for this purpose? -->
<enrich>
<source type="property" clone="true" property="xdrTicket"/>
<target type="body"/>
</enrich>
<!-- then I tried scripting... but the setPayLoadXML method also insists on tags so I've put "abc" -->
<script language="js">
var xmlPayload = mc.getPayloadXML();
var xdrTick = xmlPayload.substr(0,36);
mc.setPayloadXML(<abc>{xdrTick}</abc> );
</script>
<!-- this is posting to the queue and it works, but again, allowed formats are only POX, SOAP, REST, or AS-IS... but no PLAIN TEXT -->
<send>
<endpoint>
<address uri="jms:/VomsXdrService?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory&java.naming.provider.url=tcp://localhost:61616&transport.jms.DestinationType=queue"
format="pox"/>
</endpoint>
</send>
</inSequence>
</target>
<parameter name="transport.jms.ContentType">
<rules xmlns="">
<jmsProperty>contentType</jmsProperty>
<default>text/plain; charset=ISO-8859-1</default>
</rules>
</parameter>
<parameter name="ContentType" value="text/plain"/>
<parameter name="transports">jms</parameter>
<description/>
</proxy>
The request is like the following:
<body>
<p:writeXDRRequest xmlns:p="http://api.service.com/">
<xsd:arg0 xmlns:xsd="http://api.service.com/">VOMS</xsd:arg0>
<xsd:arg1 xmlns:xsd="http://api.service.com/">SDR</xsd:arg1>
<xsd:arg2 xmlns:xsd="http://api.service.com/">1.0|321|2014-09-24T13:25:19.183+0000</xsd:arg2>
</p:writeXDRRequest>
</body>
On the queue, only the value of arg2 is expected, in plain text, without any tags:
1.0|321|2014-09-24T13:25:19.183+0000

Answer 1

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
name="VomsXdrPlain"
transports="http"
statistics="disable"
trace="enable"
startOnLoad="true">
<target>
<inSequence>
<payloadFactory media-type="xml">
<format>
<text xmlns="http://ws.apache.org/commons/ns/payload">$1</text>
</format>
<args>
<arg xmlns:xsd="http://api.service.com/"
evaluator="xml"
expression="//xsd:arg2"/>
</args>
</payloadFactory>
<property name="OUT_ONLY" value="true"/>
<property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>
<property name="messageType" value="text/plain; charset=windows-1252" scope="axis2"/>
<!-- this is posting to the queue and it works, but again, allowed formats are only POX, SOAP, REST, or AS-IS... but no PLAIN TEXT -->
<send>
<endpoint>
<address uri="jms:/dynamicQueues/TestQueue?transport.jms.ConnectionFactory=myQueueConnectionFactory"/>
</endpoint>
</send>
</inSequence>
</target>
<description/>
</proxy>
see https://docs.wso2.com/display/ESB481/Converting+the+SOAP+Messages+to+Plain+Text+Mail