KState-Saga/ca.acendas.kstate.saga/CompensationScope

CompensationScope

class CompensationScope<R, S>(val result: R, val state: S)

Scope for compensation execution, providing access to both step result and saga state.

This scope is the receiver for compensation lambdas, enabling "smart compensation" where the compensation logic can make decisions based on:

result: The result produced by this specific step's forward action
state: The current saga state, including updates from later steps

Example: Smart Compensation

// Step 1: Take payment
first `do` "take-payment" with { cart ->
    updateState { it.copy(paymentAmount = payment.amount) }
    createTransaction(cart)
} and undo {
    // Smart compensation: behavior depends on later steps
    when {
        state.escrowCaptured -> {
            // Step 3 captured escrow - need to dispense physical refund
            cashManager.dispenseCashRefund(state.paymentAmount)
        }
        state.paymentAmount > 0 -> {
            // Escrow exists but wasn't captured - just return it
            cashManager.returnEscrow()
        }
        else -> {
            // No payment received
            cashManager.disableAcceptors()
        }
    }
}

// Step 3: Capture escrow (sets escrowCaptured = true)
then `do` "capture-payment" with { cart ->
    cashManager.captureEscrow()
    updateState { it.copy(escrowCaptured = true) }
    result
}

Parameters

The type of result produced by this step

The type of shared saga state

Constructors

CompensationScope

constructor(result: R, state: S)

Properties

result

val result: R

Result produced by this step's forward action.

state

val state: S

Current saga state at the time of compensation.