Concat operation in property mediator of wso2 is invalid - wso2

Question

<property name="Code" expression="json-eval($.Code)" scope="default" type="STRING"/>
<property name="Endpoint" expression="json-eval($.data.InternalConfig.Events.Code.Endpoint)" scope="default"
<property expression="fn:concat(json-eval($.data.InternalConfig.Events'.'get-property('Code')'.'Endpoint)" name="URL" type="STRING" scope="default"/>
one property is fetching from payload and another from respository , i am trying to merge into 1 property

Answer 1

I believe that you are trying to extract the data from the payload using dynamic values during the runtime. If yes, we can make use of Script Mediator in the WSO2 platform to access the JSON payloads.
For example:
Given below is a sample payload, and you are trying to extract the data: 'some value here' from the payload using the code and endpoint values
{
"userId": 10,
"code": 1,
"body": {
"id": 2,
"endpoint": "some-key",
"1": {
"anotherId": 30,
"title": "Lorum ipsum",
"some-key": "some value here"
}
}
}
Given below is a sample mediation sequence with the Script mediator to achieve your requirement
<?xml version="1.0" encoding="UTF-8"?><sequence xmlns="http://ws.apache.org/ns/synapse" name="mediation-sequence">
<script language="js">
<![CDATA[
// read the JSON payload from the message context
var payload = mc.getPayloadJSON();
// read the property values
var code = payload["code"];
var endpoint = payload["body"]["endpoint"];
var extracted_value = payload["body"][code][endpoint];
// set the extracted value as property to message context
mc.setProperty("ExtractedValue", extracted_value);
]]>
</script>
<log level="custom">
<property name="Extracted value" expression="$ctx:ExtractedValue" />
</log>
</sequence>
Hope this helps you to achieve your requirement.