Tapertry中的contrib:When和contrib:Otherwise如何使用？

Question

<span jwcid="@contrib:Choose">
                 <span jwcid="@contrib:When" condition="ognl: count == 0">
                    Your search did not match any documents.
                 </span>
                 <span jwcid="@contrib:Otherwise">
                    <span jwcid="@Insert" value="ognl: count">51</span>&nbsp;documents matched your selection.
                 </span>
              </span>

Answer 1

<span jwcid="@contrib:Choose>
                 <span jwcid="@contrib:When" condition='ognl:"visitor".equals(user.category)'>
                    ...
                 </span>
                 <span jwcid="@contrib:When" condition='ognl:"member".equals(user.category)'>
                    ...
                 </span>
                 <span jwcid="@contrib:When" condition='ognl:"customer".equals(user.category)'>
                    <span jwcid="@contrib:Choose>
                       <span jwcid="@contrib:When" condition='ognl:"person".equals(user.profile)'>
                          ...
                       </span>
                       <span jwcid="@contrib:When" condition='ognl:"enterprise".equals(user.profile)'>
                          ...
                       </span>
                    </span>
                 </span>
                 <span jwcid="@contrib:Otherwise">
                    ...
                 </span>
              </span>