t:dataTable DataModel must exist when using sorting?

[Rogerio Pereira]

Hi guys,

I have a dataTable that only filled after execute a method on my bean,  this  table uses sorting using this code:

                    <t:dataTable
                            var="item"
                            value="#{bean.results}"
                            preserveDataModel="false"
                            renderedIfEmpty="false"
                            sortable="true"                       
                            sortColumn="#{bean.sortColumn}"
                            sortAscending="#{bean.sortAscending}"
                            preserveSort="true"                            
                            rows="10"
                       >

                        <t:column defaultSorted="true">
                           <f:facet name="header"> 
                              <h:outputText value="ID" />               
                           </f:facet>
                           <h:outputText value="#{ item.id}" /> 
                        </t:column>

                    </t:dataTable>

and this bean:

public abstract class Bean
{
    //Variaveis de uso interno do bean
    private String     keyword;
    private String     sortColumn = null;
    private boolean sortAscending = true;
    private List     results;

   ...

   getters and setters
   ...

   public String search()
   {
       results = new ArrayList();
       ...
       fill results ArrayList with some entity instances
       ...
   }
}

but when i load the page i get this error:

java.lang.NullPointerException : value
    at javax.faces.component._ComponentChildrenList.checkValue(_ComponentChildrenList.java:93)
    at javax.faces.component._ComponentChildrenList.add(_ComponentChildrenList.java:61)
    at org.apache.myfaces.component.html.ext.HtmlDataTable.createSortHeaderComponent (HtmlDataTable.java:538)
    at org.apache.myfaces.component.html.ext.HtmlDataTable.encodeBegin(HtmlDataTable.java:490)
    at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:232)
    at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:239)
    at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:239)
    at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive (ComponentSupport.java:239)
    at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:239)
    at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:580)
    at org.apache.myfaces.lifecycle.LifecycleImpl.render (LifecycleImpl.java:384)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:138)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter (ApplicationFilterChain.java:173)
    at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:181)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java :202)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke (StandardContextValve.java:178)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    at org.apache.catalina.core.StandardEngineValve.invoke (StandardEngineValve.java:107)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection (Http11BaseProtocol.java:664)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java :80)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
    at java.lang.Thread.run(Unknown Source)

Any ideas?

--
Yours truly (Atenciosamente),

Rogério