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The omnifaces.SelectItemsIndexConverter is a variant of the SelectItemsConverter which automatically converts based on the position (index) of the selected item in the list instead of the #toString() of the selected item.

Usage

This converter is available by converter ID omnifaces.SelectItemsIndexConverter. Just specify it in the converter attribute of the selection component holding <f:selectItems>.

 <h:selectOneMenu value="#{bean.selectedItem}" converter="omnifaces.SelectItemsIndexConverter">
     <f:selectItems value="#{bean.availableItems}" />
 </h:selectOneMenu>
 

Since OmniFaces 4.5 it's also available by <o:selectItemsIndexConverter> tag.

 <h:selectOneMenu value="#{bean.selectedItem}">
     <f:selectItems value="#{bean.availableItems}" />
     <o:selectItemsIndexConverter />
 </h:selectOneMenu>
 

Pros and cons as compared to SelectItemsConverter

This converter has the following advantages over SelectItemsConverter:

• No need to rely on #toString() method of the object.
• No need to extend the SelectItemsConverter when #toString() method of the object cannot be used.
• No need to expose the object's unique key in its #toString(),if that's a problem.

This converter has the following disadvantage over SelectItemsConverter:

• The "Validation Error: value is not valid" will never occur anymore for the case that the available select items has incompatibly changed during the postback due to a developer's mistake. The developer should make absolutely sure that exactly the same list is preserved on postback (e.g. by making it a property of a view scoped or broader scoped bean).