EclipseWtpFacet

plugins {
    id 'war' // or 'ear' or 'java'
    id 'eclipse-wtp'
}

eclipse {
  wtp {
    facet {
      //you can add some extra wtp facets or update existing ones; mandatory keys: 'name', 'version':
      facet name: 'someCoolFacet', version: '1.3'

      file {
        //if you want to mess with the resulting XML in whatever way you fancy
        withXml {
          def node = it.asNode()
          node.appendNode('xml', 'is what I love')
        }

        //beforeMerged and whenMerged closures are the highest voodoo for the tricky edge cases.
        //the type passed to the closures is WtpFacet

        //closure executed after wtp facet file content is loaded from existing file
        //but before gradle build information is merged
        beforeMerged { wtpFacet ->
          //tinker with WtpFacet here
        }

        //closure executed after wtp facet file content is loaded from existing file
        //and after gradle build information is merged
        whenMerged { wtpFacet ->
          //you can tinker with the WtpFacet here
        }
      }
    }
  }
}