<ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets"
                xmlns:p="http://primefaces.org/ui" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core">

    <h:panelGroup  rendered="true">
        <table align="center">
            <tr>
                <td style="padding: 5px;"> 
                    <p:commandButton styleClass="btn btn-success btn-block" style="width: 150px"
                                     actionListener="#{backBean.onRefresh}" value="Refresh" update="#{backBean.updateRefresh}" /></td>
            </tr>
        </table>
    </h:panelGroup>

</ui:composition>