Failed to create timeline view

[kasaba]

Hi, fellows

I have two views details and timeline. There's situation when I have
only one result which doesn't contain
date (<td><span ex:content=".creationDate" /></td>) and then when I
click on view timeline exhibit throw an error - "Failed to create
timeline view" and then exhibit is broken. Is there any way when I
have not even one result with set .creationDate link to Timeline view
to be hidden, or when I click on timeine link to be open my
confirmation dialog for example with the text "There's neither one
creationDate to be visualised Timeline" and exhibit not to be broken
when click on views. That's my jsf code.
<div ex:role="view" ex:label="Details" ex:viewClass="Tile"
ex:paginate="true" ex:pageSize="2" ex:page="0"
ex:pageWindow="99"
ex:alwaysShowPagingControls="true">
<table ex:role="lens">
<tr><div>
<span ex:content=".creator" />
</div>
</td>
</tr>
</table>
</div>
<div ex:role="view" ex:viewClass="Timeline"
ex:start=".creationDate" ex:colorKey=".label">
<table ex:role="lens">
<tr>
<td width="150px" style="font-weight: bold;"><h:outputText
value="#{messages['title']}" />:</td>
<td><span ex:content=".label" /></td>
</tr>
<tr>
<td width="150px" style="font-weight: bold;"><h:outputText
value="#{messages['date.creation']}" />:</td>
<td><span ex:content=".creationDate" /></td>
</tr>
</table>
</div>

Thanks in advance.