id attribute of subview tag

Question

I am learning jsf. I get class cast exception in java.lang.String when I use the following code:

<f:facet name="header">
  <f:subview id="header">
    <tiles:insert attribute="header" flush="false"/>
  </f:subview>
</f:facet>

If I replace the subview id with another name other than header the code runs successfully. Eg

<f:facet name="header">
  <f:subview id="header1">
    <tiles:insert attribute="header" flush="false"/>
  </f:subview>
</f:facet>

I am using core java server faces book by David Geary and Cay Horstmann. The example given in the book has same value for facet name and subview id. Please explain why we should give different values for facet name and subview id.

Answer 1

The component tree uses ids to reference everything. With jsf you should always reference everything with a unique id or you can let jsf do it but if you do explicitly specify the same name in more than one tag you will have problems.