Flutter SDK / Rendering flows

Rendering flows

UpliftFunnelFlow is the whole integration in one widget: it fetches the flow by key, caches it, shows loading and error states, renders every screen natively, and hands you the result.

dart

UpliftFunnelFlow(
  'welcome',                       // flow key from the dashboard
  onCompleted: (result) {
    if (result.endReason == 'completed') {
      // Persist answers, route into the app…
      saveProfile(result.variables);
    }
    Navigator.of(context).pushReplacementNamed('/home');
  },
)

Constructor

Parameter	Type	Default	Description
flowKey	String	—	Positional. The flow's key (slug) from the dashboard.
onCompleted	void Function(UpliftFunnelFlowResult)?	—	Called exactly once when the flow ends — whether completed, skipped, or abandoned. Inspect endReason to tell them apart.
unsupportedBuilder	WidgetBuilder?	nothing rendered	What to show where the engine does not run. The default is an empty box rather than a crash, but `UpliftFunnel.isSupported` is the honest way to branch.
userVariables	Map<String, Object?>?	—	Values injected into the flow session, available to screens as `{{variable}}` placeholders and to branching rules.
forceRefresh	bool	false	Skip the device cache and await a fresh fetch from the network.

UpliftFunnelFlow.experiment(key, …) takes the same parameters but treats the key as an experiment key:

dart

UpliftFunnelFlow.experiment(
  'onboarding-test',               // experiment key, not a flow key
  onCompleted: (result) {
    final exp = result.experiment; // (experimentId, variantId) — or null
    _finish(result);
  },
)

The result

Field	Type	Description
endReason	String	How the flow ended: `completed`, `abandoned`, `skipped`, or a custom `end:<reason>` defined in the editor.
variables	Map<String, String>	Every answer collected over the session — quiz answers, selected plan, text inputs. Values are strings: they cross the channel as the engine stored them, and a flow variable is text by the time it is saved.
source	String	Where the flow came from: `network`, `cache`, or `cacheRevalidated`. Useful for surfacing offline state.
experiment	({String experimentId, String variantId})?	The A/B assignment the session ran under, as a record, or null for a plain flow.

Custom loading & error states

dart

if (!UpliftFunnel.isSupported) return const MyOwnOnboarding();

UpliftFunnelFlow(
  'welcome',
  userVariables: {'name': user.firstName},   // usable as {{name}} in screens
  forceRefresh: false,
  unsupportedBuilder: (context) => const MyOwnOnboarding(),
  onCompleted: (result) => _finish(result),
)

The loading and error states are the engine's own, rendered inside your widget tree, and the error one already offers a retry — there is nothing to pass for them. Caching, offline & errors covers how a failure is classified, and how often the cache means you never see one.