Command_link rendered value binding causes NullPointerException

Question

command_link is put in a data_table. Intiailly, data_table has no rows. The command_link's render attribute is binded to a property of a row bean. e.g.
<h:data_table id="resourcesTable"
  value="#{mainPubFormBean.resources}"
  binding="#{mainPubFormBean.dataUI}"
  var="resourceDataLine">
    <h:column>
      <h:command_link id="goToFolder"
      action="#{mainPubFormBean.goToResource}"
      rendered="#{resourceDataLine.folder}"
      title="#{resourceDataLine.localizedResourceName}">
       <h:output_text   value="#{resourceDataLine.abbreviatedResourceName}"
          styleClass="time-table-text"/>
       </h:command_link>
    </h:column>
</h:data_table>It causes NullPointerException,
java.lang.NullPointerException
        at javax.faces.component.UIComponentBase.isRendered(UIComponentBase.java:415)
        at javax.faces.webapp.UIComponentTag.isSuppressed(UIComponentTag.java:777)
        at javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:447)
        at com.sun.faces.taglib.BaseComponentTag.doStartTag(BaseComponentTag.java:929)
        at org.apache.jsp.main_jsp._jspx_meth_h_command_link_6(main_jsp.java:1954)
        at org.apache.jsp.main_jsp._jspx_meth_h_column_0(main_jsp.java:1834)
        at org.apache.jsp.main_jsp._jspx_meth_h_data_table_0(main_jsp.java:1498)Here is the UIComponentBase.isRendered code fragment:
    public boolean isRendered()
        if(renderedSet)
            return rendered;
        ValueBinding vb = getValueBinding("rendered");
        if(vb != null)
            Boolean value = (Boolean)vb.getValue(getFacesContext());
            return value.booleanValue();  <----- value can be null
        } else
            return rendered;
    }The code should test if the value if null or not before calling booleanValue().

Answer 1

Thanks. Good news: we already nailed this bug.
-- Adam Winer