WSO2 EI For通过Json数组循环

Question

I have a below request (i am using WSO2 Enterprise integrator 6.5.0):

And I wanna get this in jsonpayload which is returned client

<ERROR_RESP>
    <ERROR>
        <ECODE>ST-VALS-002</ECODE>
        <EDESC>Record Not Found  for Branch Code-CHO:Currency 1-USD:Currency 2-MN</EDESC>
    </ERROR>
    <ERROR>
        <ECODE>ST-SAVE-024</ECODE>
        <EDESC>Failed to Query Data</EDESC>
    </ERROR>
</ERROR_RESP>

It is my tried code to achieve it :

<foreach expression="json-eval($.ERROR_RESP.ERROR)">
    <sequence>
        <payloadFactory media-type="json">
            <format>
            { 
                "ErrorCode" : "$1", 
                "ErrorMessage" : "$2"  
            }
                </format>
            <args>
                <arg evaluator="json" expression="$.ECODE"/>
                <arg evaluator="json" expression="$.EDESC"/>
            </args>
        </payloadFactory>
        <log level="full">
            <property name="MESSAGE" value="ENDLOOP"/>
        </log>
        <loopback/>
    </sequence>
</foreach> 
enter code here

I did some search but nothings worked, I think foreach expression is not right.

Thanks

Regards,

Answer 1

In your sample the Loopback mediator is used. It will be used to move the message to the out flow (response path). Therefore, the Foreach mediator splits the message and sends the first message to the response path and end the flow.

You can prepare the XML payload and convert it to JSON using the messageType property with axis2 scope as follows.

    <foreach expression="//ERROR">
        <sequence>
           <payloadFactory media-type="xml">
              <format>
                 <ERROR xmlns="">
                    <ErrorCode>$1</ErrorCode>
                    <ErrorMessage>$2</ErrorMessage>
                 </ERROR>
              </format>
              <args>
                 <arg evaluator="xml" expression="//ECODE/text()"/>
                 <arg evaluator="xml" expression="//EDESC/text()"/>
              </args>
           </payloadFactory>
        </sequence>
     </foreach>
     <property name="messageType" scope="axis2" value="application/json"/>

The final message will be like this:

{
    "ERROR_RESP": {
        "ERROR": [
            {
                "ErrorCode": "ST-VALS-002",
                "ErrorMessage": "Record Not Found  for Branch Code-CHO:Currency 1-USD:Currency 2-MN"
            },
            {
                "ErrorCode": "ST-SAVE-024",
                "ErrorMessage": "Failed to Query Data"
            }
        ]
    }
}

Answer 2

At the moment, foreach mediator in EI 6.5.0 does not support "json-eval()" expressions. This feature will be included in the upcoming versions.

As a workaround, you can use XPath inside the expression. You can use this blog as an example. https://medium.com/@Manuri/wso2-esb-foreach-mediator-example-87f041e2a912