Package org.apache.tapestry5.ioc.def

# Interface ContributionDef3

All Superinterfaces:
  `ContributionDef`, `ContributionDef2`, `Markable`

All Known Implementing Classes:
  `ContributionDefImpl`

public interface ContributionDef3 extends ContributionDef2
Starting in Tapestry 5.3, contributions could be optional.

Since:
  5.3
See Also:
  - `Optional`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `boolean`
  `isOptional()`
  Is this contribution optional, meaning it is not an error if the service to which the contribution is targetted does not exist.

  ### Methods inherited from interface org.apache.tapestry5.ioc.def.ContributionDef

  `contribute, contribute, contribute, getServiceId`

  ### Methods inherited from interface org.apache.tapestry5.ioc.Markable

  `getMarkers, getServiceInterface`

- ## Method Details

  - ### isOptional

    boolean isOptional()
    Is this contribution optional, meaning it is not an error if the service to which the contribution is targetted does not exist.