Module org.omnifaces
Package org.omnifaces.component.output

Class Param<T>

java.lang.Object
jakarta.faces.component.UIComponent
jakarta.faces.component.UIComponentBase
jakarta.faces.component.UIParameter
org.omnifaces.component.output.Param<T>
Type Parameters:
T - The type of the value.
All Implemented Interfaces:
PartialStateHolder, StateHolder, TransientStateHolder, ValueHolder, ComponentSystemEventListener, FacesListener, SystemEventListenerHolder, EventListener, ParamHolder<T>
Direct Known Subclasses:
PathParam
public class Param<T> extends UIParameter implements ParamHolder<T>

The <o:param> is a component that extends the standard UIParameter to implement ValueHolder and thus support a Converter to convert the supplied value to string, if necessary.

You can use it the same way as <f:param>, you only need to change f: into o: to get the extra support for a Converter by usual means via the converter attribute of the tag, or the nested <f:converter> tag, or just automatically if a converter is already registered for the target class via @FacesConverter(forClass).

Also, if no value is specified, but children are present, then the encoded output of children will be returned as param value. This is useful when you want to supply Faces components or HTML as parameter of an unescaped <h:outputFormat>. For example, 

 <h:outputFormat value="#{bundle.paragraph}" escape="false">
     <o:param><h:link outcome="contact" value="#{bundle.contact}" /></o:param>
 </h:outputFormat>

with this bundle 

 paragraph = Please {0} for more information.
 contact = contact us

will result in the link being actually encoded as output format parameter value.

Since:
1.4
Author:
Bauke Scholtz
See Also: