title: action and actionListener for p:commandButton in composite component
body: <p>I am making composite component where i have commandButton. But it doesn't work. </p>
  
  <p>Usage:</p>
  
  <pre><code>&lt;wk:commandButton value="Non-Ajax actionListener" actionListener="#{ioBean.saveListener}" /&gt;  
  </code></pre>
  
  <p>Code of component: commandButton.xhtml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;!DOCTYPE html&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:c="http://java.sun.com/jsp/jstl/core"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:p="http://primefaces.org/ui"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:cc="http://java.sun.com/jsf/composite"&gt;
  &lt;cc:interface&gt;
      &lt;cc:attribute name="value" /&gt;
      &lt;cc:attribute name="action" method-signature="void action(javax.faces.event.ActionEvent)" default="null"/&gt;
      &lt;cc:attribute name="actionListener" method-signature="void actionListener(javax.faces.event.ActionEvent)" default="null"/&gt;
      &lt;cc:attribute name="styleClass" default="button" /&gt;
  &lt;/cc:interface&gt;
      &lt;cc:implementation&gt;
              &lt;p:commandButton
                              value="#{cc.attrs.value}"
                              action="#{cc.attrs.action}"
                              actionListener="#{cc.attrs.actionListener}"
                              styleClass="#{styleClass}"&gt;
                  &lt;cc:insertChildren /&gt;
              &lt;/p:commandButton&gt;
      &lt;/cc:implementation&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>And this is log:</p>
  
  <pre><code>0000006c FaceletViewDe E   Inner component action not found when retargetMethodExpressions
  0000006c FaceletViewDe E   Inner component actionListener not found when retargetMethodExpressions
  0000006c srt           W com.ibm.ws.webcontainer.srt.SRTServletResponse setIntHeader SRVE8094W: Ostrzeżenie: nie można ustawić nagłówka. Odpowiedź została już zatwierdzona.
  </code></pre>
  
  <p>I think the problem is with default value for action and actionListener. But according to the PrimeFaces documentation, default value for action and actionListener is null.
  One option is to make four different variants where action and actionListener are null or are defined but it doedn't seem to be good solution.</p>