Handlers

Handlers should be small adapters around domain services. Keep orchestration in the flow definition and domain logic in services that can be tested independently.

  1. Type dependencies in the constructor.
  2. Read input from FlowContext.
  3. Return FlowStepResult::success() or a failure result.
  4. Put irreversible side effects behind a compensator where possible.
  5. Add business impact when the result matters to operators or previews.
final class CapturePayment implements FlowStepHandler
{
    public function __construct(private PaymentGateway $gateway) {}

    public function handle(FlowContext $context): FlowStepResult
    {
        $charge = $this->gateway->capture($context->input()['order_id']);

        return FlowStepResult::success(output: [
            'charge_id' => $charge->id,
        ]);
    }
}
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