Filtering in WSO2

I want to build one proxy that:
1. Call Service that do Authorize and give result OK or Fail (1st Service)
2. If Result ‘OK’ then call a Service

The Problem is, when The 1st Service give back the Message :

<?xml version='1.0' encoding='utf-8'?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
       <soapenv:Body>
              <result>
                     <status>OK</status>
                     <message></message>
              </result>
       </soapenv:Body>
</soapenv:Envelope>

And I give “filtering” at Out Sequence. Here is the XML :

<proxy xmlns="http://ws.apache.org/ns/synapse" name="TestProxy" transports="https,http" statistics="disable" trace="enable" startOnLoad="true">
   <target endpoint="AuthorizationService">
      <outSequence>
         <log level="full" />
         <filter xpath="/result/status='OK'">
            <then>
               <send>
                  <endpoint>
                     <address uri="http://192.168.1.140:8080/axis2/services/TaskService.TaskServiceHttpEndpoint/getTask" />
                  </endpoint>
               </send>
            </then>
            <else>
               <makefault version="soap11">
                  <code xmlns:soap11Env="http://schemas.xmlsoap.org/soap/envelope/" value="soap11Env:VersionMismatch" />
                  <reason value="1" />
                  <role>2</role>
                  <detail>3</detail>
               </makefault>
            </else>
         </filter>
         <log level="full" />
      </outSequence>
   </target>
</proxy>

When I run my Application, the ESB always give the message :

16:08:59,358 [-] [HttpClientWorker-4] INFO Start : Log mediator 
16:08:59,361 [-] [HttpClientWorker-4] INFO To: http://www.w3.org/2005/08/addressing/anonymous, WSAction: , SOAPAction: , MessageID: urn:uuid:0bc33821-c4f1-448e-a7dc-be4194be8e99, Direction: response, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><result><status>OK</status><message></message></result></soapenv:Body></soapenv:Envelope> 
16:08:59,361 [-] [HttpClientWorker-4] INFO End : Log mediator 
16:08:59,361 [-] [HttpClientWorker-4] INFO Start : Filter mediator 
16:08:59,361 [-] [HttpClientWorker-4] INFO XPath expression : /result/status='OK' evaluates to false - executing the else path child mediators

Seems like the condition of the filtering is always false.
What is the correct statement for the XPath in the filter?

Solution

It seems that you may have given a wrong xpath expression. You can't give an xpath and a boolean expression both for the xpath value, i.e. it can't be "/result/status='OK'", but has to be "/result/status". Then, according to your sequence, it would fire the section after then, if this element is present. Since, you need to evaluate a boolean condition as well based on the xpath, I'll present an alternative based on the switch mediator (Same can be done for the filter by setting a property):

<proxy xmlns="http://ws.apache.org/ns/synapse" name="TestProxy" transports="https,http" statistics="disable" trace="enable" startOnLoad="true">
   <target endpoint="AuthorizationService">
      <outSequence>
         <log level="full" />
         <switch source="//result/status">
            <case regex="OK">
               <send>
                  <endpoint>
                     <address uri="http://192.168.1.140:8080/axis2/services/TaskService.TaskServiceHttpEndpoint/getTask" />
                  </endpoint>
               </send>
            </case>
            <default>
               <makefault version="soap11">
                  <code xmlns:soap11Env="http://schemas.xmlsoap.org/soap/envelope/" value="soap11Env:VersionMismatch" />
                  <reason value="1" />
                  <role>2</role>
                  <detail>3</detail>
               </makefault>
            </default>
         </switch>
         <log level="full" />
      </outSequence>
   </target>
</proxy>