Binding in JSF not working - jsf

Question

I am trying to make a h:panelgrid visible and invisible by clicking on a button that's why i made this code:
<p:menu styleClass="ui-menubar" style="width:auto">
<p:menuitem value="khraaaaaaaaa" actionListener="#{accounts.buttonUser()}"></p:menuitem>
</p:menu>
<h:panelGrid id="naalobouk" binding="#{accounts.pg1}">
<h1>Activer/désactiver un compte étudiant</h1>
<hr/>
<h:form id="etudiants">
<p:dataTable emptyMessage="Pas d'étudiant!"
paginator="true"
paginatorPosition="bottom"
rows="4"
value="#{accounts.etudiants}"
var="stu">
<f:facet name="header">
<h:outputText value="Les comptes étudiant" />
</f:facet>
<p:column headerText="#">
<h:outputText value="#{stu.id}" />
</p:column>
<p:column headerText="nom">
<h:outputText value="#{stu.nom}" />
</p:column>
<p:column headerText="prenom">
<h:outputText value="#{stu.prenom}" />
</p:column>
<p:column headerText="email">
<h:outputText value="#{stu.email}" />
</p:column>
<p:column headerText="password">
<h:outputText value="#{stu.password}" />
</p:column>
<p:column headerText="action">
<p:commandButton rendered="#{accounts.butshow}" value="#{stu.actif?'desactiver':'activer'}" action="#{accounts.doToggleStudentState(stu)}" update=":etudiants"/>
</p:column>
</p:dataTable>
</h:form>
</h:panelGrid>
and here is my bean code
private HtmlPanelGrid pg1 = new HtmlPanelGrid();//getter and setter
public void buttonUser(){
if(pg1.isRendered()==true){
pg1.setRendered(false);;
}
if(pg1.isRendered()==false){
pg1.setRendered(true);
}
}
When i click on the button nothing happens. What's the problem here ?

Answer 1

I'm assuming you want the method to negate the rendered property. In that case the method is flawed, as mentioned in the comments. The simplest code would be
public void buttonUser() {
pg1.setRendered(!pg1.isRendered());
}
The main problem is that the p:menuItem by default uses ajax, which by default does'nt update anything on the page. So either update something, or don't use ajax;
<p:menuitem value="khraaaaaaaaa" actionListener="#{accounts.buttonUser()}" ajax="false">
With ajax you need to wrap the panelGrid in a component that will always be rendered, since you can't update a component that has not been rendered in the first place. Wrap the panelGrid in a panelGroup:
<h:panelGroup id="container">
and update that:
<p:menuitem value="khraaaaaaaaa" actionListener="#{accounts.buttonUser()}" update=":container">