Package org.apache.tapestry5.ioc.annotations

Annotation Type Optional

@Target(METHOD)
@Retention(RUNTIME)
@Documented
@UseWith(MODULE)
public @interface Optional

Marks a service contribution method within a module as being optional: it is not an error if the contribution does not match against an actual service. In that case, the method will simply never be invoked. This is occasionally useful when a module is designed to work with another module if the second module is present. Without optional contributions, you would see hard errors when registry is created, and have to create a layer cake of small modules to prevent such errors.

Since:

5.3

See Also:

Contribute, ContributionDef3.isOptional()