Hiding a plugin extension on some property? How can we do this?

I want to hide the some portlets on summary section view on the basis of particular property which comes from PropertyProvider Adapter class. Can you please help on this?

I refer the following example for hiding the summary portlet for rack section but its not working. Please tell where i was wrong.

<extension id="com.vmware.samples.rack.RackSummaryView">

      <extendedPoint>com.vmware.samples.rack.summarySectionViews</extendedPoint>

      <object>

         <name>Test Portlet</name>

         <componentClass className="com.vmware.samples.chassisrackui.views.RackSummaryView"/>

      </object>     

      <metadata>

        <objectType>samples:Rack</objectType>

         <conditions>

           <com.vmware.data.query.PropertyConstraint>

              <propertyName>chassis</propertyName>

              <comparator>EQUALS</comparator>

              <comparableValue>

                 <String>false</String>

              </comparableValue>

           </com.vmware.data.query.PropertyConstraint>

          </conditions>

    </metadata>

   </extension>