title: JSF selectOneButton with ajax update lost value
body: <p>I use Primefaces 3.2 with Apache Myfaces 2 on WebSphere Application Server 8.</p>
  
  <p>I have a form, where you can select 2 different view by changing a selectOneButton.</p>
  
  <p>When I use this button without ajax behavior (submit with command button) then the value change works fine.</p>
  
  <p>But when I use something like this:</p>
  
  <pre><code>&lt;h:form id="form"&gt;
      &lt;p:panel header="Panel" toggleable="true" closable="true" id="pan1"&gt;
              &lt;p:panel header="Options" toggleable="true" collapsed="true" id="pan2"&gt;
                  &lt;p:panelGrid style="width:100%; text-align:center;" id="pan3"&gt;
                      &lt;p:row&gt;
                          &lt;!-- some outputLabels --&gt;
  
                          &lt;p:column rowspan="2" style="width:130px;"&gt;
                              &lt;p:splitButton value="Show" action="#{ graph.update }"
                                  update=":form" id="splitbtn"&gt;
                                  &lt;p:menuitem value="Update 2"
                                      action="#{ graph.update2 }"
                                      update=":form" /&gt;
                              &lt;/p:splitButton&gt;
                          &lt;/p:column&gt;
                      &lt;/p:row&gt;
                      &lt;p:row&gt;
  
                          &lt;p:column&gt;
                              &lt;p:selectOneButton id="btn1"
                                  value="#{ bean.val }"&gt;
                                  &lt;f:selectItem itemLabel="lbl1" itemValue="1" /&gt;
                                  &lt;f:selectItem itemLabel="lbl2" itemValue="2" /&gt;
                                  &lt;p:ajax event="change"
                                      update=":firstChartForm" /&gt;
                              &lt;/p:selectOneButton&gt;
                          &lt;/p:column&gt;
  
                          &lt;!--  more coloumns --&gt;
                      &lt;/p:row&gt;
                    &lt;/p:panel&gt;
                    &lt;!-- more content --&gt;
               &lt;/p:panel&gt;
          &lt;/h:form&gt;
  </code></pre>
  
  <p>Then the value of bean.val is empty when I change the button and update the form with ajax.
  (Logger in setter method prints 2 times empty value).</p>
  
  <p>Why is the value empty?</p>