Getting a NullPointerException while Partial rendering via FacesContext - jsf

Question

I have a strange behavior where I am getting NPE while doing page refresh using faces context.
I have a managed bean which is in Request Scope. So want to refresh the page after click on commandbutton. I have tried with 'update' but it is behaving strange in my page.
Error: PartialViewContextImpl$PhaseAwareVisitCallback.visit : java.lang.NullPointerException
This is my JSF page:
<h:form id="form">
<p:messages autoUpdate="true"/>
<h:panelGrid columns="4" cellpadding="5" id="panelGrid" rendered="true">
<p:outputLabel for="s00" value="#{tk.expense_keyword}"/>
<p:inputText id="s00" value="#{expense.form.keyword}"/>
<p:outputLabel for="s02" value="#{tk.expense_creatorId}"/>
<p:inputText id="s02" value="#{expense.form.creatorId}" disabled="#{!expense.form.canEditCreatorId}"/>
<h:outputText id="s10" value="Amount Between #{expense.form.amountFrom} and #{expense.form.amountTo}" />
<h:panelGrid>
<p:slider for="s11,s12" display="s10" minValue="0" maxValue="1000" style="width: 200px" range="true" displayTemplate="Amount Between {min} and {max}" />
<h:inputHidden id="s11" value="#{expense.form.amountFrom}" />
<h:inputHidden id="s12" value="#{expense.form.amountTo}" />
</h:panelGrid>
</h:panelGrid>
<p:commandButton value="#{tk.expense_search}" id="a01" action="#{expense.search}" ajax="false" immediate="true"/>
<p:dataTable var="line" varStatus="loop" value="#{expense.form.expenseEntryList}" emptyMessage="#{tk.expense_table_empty}" id="dataTable">
<p:column headerText="#{tk.expense_table_creatorId}">
<h:inputHidden value="#{line.oid}"/>
<h:inputText value="#{line.creatorId}"/>
</p:column>
<f:facet name="footer">
<p:commandButton value="#{tk.expense_saveAsDraft}" id="a06" action="#{expense.saveAsDraft}"/>
<p:commandButton value="#{tk.expense_submit}" id="a07" action="#{expense.submitAll}"/>
<p:commandButton value="#{tk.expense_validate}" id="a08" action="#{expense.validate}"/>
</f:facet>
</p:dataTable>
</h:form>
Here when I click on Save As Draft I want to refresh the page. So I am using FacesContext's method to refresh the page.
Here is my method saveAsDraft:
public Outcome saveAsDraft() throws Exception{
try {
saveAsDraftBody(false,false);
getFacesContext().getPartialViewContext().getRenderIds().add("form:panelGrid");**//**getting error****
getFacesContext().getPartialViewContext().getRenderIds().add("form:dataTable");**//**works fine****
Log.info(this,"getFacesContext().getPartialViewContext().getRenderIds(): "+getFacesContext().getPartialViewContext().getRenderIds());
return Outcome.SUCCESS;
}
catch (Throwable e){
throw manageError(e);
}
}
I don't know why it works for data table refresh but not for panelGrid :(

Answer 1

First of all you have the bean in request scope and you are making full page submit and here the partial render does not make any sense. The error you are getting because you have component which is basically, another input into a form which will be sent to the managed bean of the current view when the form is submitted.