Other Utilities

Miscellaneous utilities provides by Vaultaire

Generated Responders

Some times you might want to use the same responding flow with multiple initiating flows. Since @InitiatedBy is not a repeatable annotation, the only option would be to subclass the same responder for each initiating flow, adding the appropriate @InitiatedBy.

Vaultaire’s annotation processor can help you automate this using a @VaultaireFlowResponder instead of maintaning such responders manually. Usage example:

// or simply: @VaultaireFlowResponder(BaseBookFlowResponder::class) 
@VaultaireFlowResponder(
    value = BaseBookFlowResponder::class,
    comment = "A basic responder to listen for finality"
)
@InitiatingFlow
@StartableByRPC
class CreateBookFlow(input: BookMessage) : FlowLogic<SignedTransaction>

The above will automatically generate a responder flow:

/**
 * A basic responder to listen for finality
 */
@InitiatedBy(value = CreateBookFlow::class)
class CreateBookFlowResponder(
  otherPartySession: FlowSession
) : BaseBookFlowResponder(otherPartySession)

Note: if the base responder flow is a final type, the generated responder will attempt to call it as a subflow instead of extending it:

@InitiatedBy(value = CreateBookFlow::class)
class CreateBookFlowResponder(
  val otherPartySession: FlowSession
) : FlowLogic<Unit>() {
  @Suspendable
  override fun call() {
    subFlow(BaseBookFlowResponder(otherPartySession))
  }
}

Results Page

The ResultsPage is a more REST-friendly alternative to Vault.Page. While it can be used to carry any type of results, it mainly focuses
on mapping StateAndRef query results to either contract states or DTOs.

Sample use:

// Use a generated state service to query
val vaultPage: Vault.Page<MyState> = stateService
    .queryBy(criteria, pageSpecification, sort)

// As states
val statesPage = ResultsPage.from(
    vaultPage, pageSpecification, sort)

// As DTOs
val dtosPage = ResultsPage.from(
    vaultPage, pageSpecification, sort
) { stateAndRefs ->
    stateAndRefs.map {
        MyStateClientDto
            .from(it.state.data, stateService)
    }
}

Vaultaire JAR Attachment

In some cases you may want to attach Vaultaire’s JAR to a Corda transaction when creating a new accounts-aware state. VaultaireAttachmentService is a Corda service to do just that:

// Obtain Vaultaire's JAR hash
val vaultaireJarAttachment = serviceHub
    .cordaService(VaultaireAttachmentService::class.java)
    .vaultaireSecureHash
// Attach JAR to TX
transactionBuilder.addAttachment(vaultaireJarAttachment)