title: wso2 - using value from a property to retrive sequence name
body: <p>I'm configuring a proxy-service and I have three sequences: s1,s2,s3</p>
  
  <p>The value of 1,2,3 is stored in a local registry variable and it's get from the registry and stored in the property called 'myProp'</p>
  
  <p>now, based on the value of this myProp I would like to call one of the three sequences.</p>
  
  <p>I tried this:</p>
  
  <pre><code>               &lt;sequence key="s{concat(get-property('myProp'))}"/&gt;
  </code></pre>
  
  <p>but doesn't works.</p>
  
  <p>This is the property code:</p>
  
  <pre><code>         &lt;property name="myProp"
                 expression="get-property('registry','conf:repository/myVersion2.xml')"
                 scope="default"
                 type="STRING"/&gt;
  </code></pre>
  
  <p>and this is what I'm trying to do:</p>
  
  <pre><code>         &lt;filter source="get-property('myProp')"
               regex=".*&amp;gt;1&amp;lt;.*"
               description="filter"&gt;
          &lt;then&gt;
             &lt;log level="custom" separator=":"&gt;
                &lt;property name="TestVersion" value="LOG_S1_TRUE"/&gt;
                &lt;property name="TestVersion" expression="get-property('myProp')"/&gt;
             &lt;/log&gt;
             &lt;sequence key="s{concat(get-property('myProp'))}"/&gt;
          &lt;/then&gt;
          &lt;else&gt;
             &lt;log level="custom" separator=":"&gt;
                &lt;property name="TestVersion" value="LOG_S1_FALSE"/&gt;
             &lt;/log&gt;
          &lt;/else&gt;
       &lt;/filter&gt;
  </code></pre>
  
  <p>I get this error from the log:</p>
  
  <pre><code>TID: [0] [ESB] [2015-07-03 12:47:25,340] ERROR {org.apache.synapse.mediators.base.SequenceMediator} -  Sequence named Value {name ='null', keyValue ='s{concat(get-property('myProp'))}'} cannot be found {org.apache.synapse.mediators.base.SequenceMediator}
  </code></pre>
  
  <p>Thanks in advance to who know how to solve it.</p>
  
  <p>Regards
  Claudio</p>