binding

var ErrBindingMisconfigured = errors.New("approval: business binding misconfigured")

ErrBindingMisconfigured signals that a Flow with BindingMode=business is missing one of the required columns (business_table / business_pk_field / business_status_field), carries an unsafe identifier, or resolved to an empty record id. The Listener acknowledges instead of retrying: a misconfiguration does not heal by retry.

var Module = fx.Module(
	"vef:approval:binding",

	fx.Provide(
		NewNoopRefProvider,
		NewIdentityResolver,
		NewWriter,
		NewListener,
	),

	fx.Invoke(func(l *Listener) error { return l.Start() }),
)

Module provides the engine-owned write-back Writer (with its default no-op BusinessRefProvider and identity BusinessRefResolver) and starts the Listener that runs the asynchronous write-back legs when the completed / returned / withdrawn / resubmitted instance events fire. (The started leg is invoked synchronously by the start_instance command inside its transaction.) Hosts replace the provider / resolver via vef.SupplyBusinessRefProvider / vef.SupplyBusinessRefResolver; the Writer itself is not an extension point.

Reliability note: the Listener is best-effort under the default in-memory event transport — a process crash between event publication and listener execution drops the write-back. Production deployments that rely on business-table consistency MUST route the approval.* instance events through the framework's outbox transport so the listener retries until acknowledged. The Listener publishes InstanceBindingFailedEvent on persistent failure so operators / saga workers can compensate; misconfigured flows (ErrBindingMisconfigured) ack immediately to avoid an infinite retry loop.