title: Primefaces Ajax Listener called twice, even if specified once
body: <p>I have two p:ajax tags registered for the same rowSelect event on a datatable. </p>
  
  <p>One p:ajax resides inside a composite component to only update common regions in the page, the other p:ajax has a listener and it is registered outside the composite component.</p>
  
  <p>I observed the listener from the outside p:ajax to be called twice. How can the listener method be executed one time only, as it is registered only on one p:ajax tag?</p>
  
  <pre><code>&lt;myComp:dataTable  ...&gt;
      &lt;p:ajax event="rowSelect" update=":form:tableDetails" listener="#{backingBean.selectRow}"/&gt;
  &lt;/myComp:dataTable&gt;
  </code></pre>
  
  <p>and here the CC code:</p>
  
  <pre><code>&lt;cc:interface &gt;
      &lt;cc:clientBehavior event="rowSelect" name="rowSelect" targets="#{cc.clientId}:dataTable" /&gt;
  &lt;/cc:interface&gt;
  &lt;cc:implementation&gt;
      &lt;p:dataTable    id="dataTable" ...&gt;
        &lt;p:ajax event="rowSelect" update=":form:footPanelAndButtons"/&gt;
      &lt;/p:dataTable&gt;
  &lt;/cc:implementation&gt;
  </code></pre>
  
  <p>I omitted the most of the attributes on the tags to keep it simple.</p>
  
  <p>I know this is might be a performance issue since client/server communication occurs twice for the same event.</p>