setup abstract method

The setup function that runs once when the widget is created.

This function is called during the first build (after initState but before the first frame is rendered). It executes only once during the widget's lifetime.

Use this function to:

• Initialize reactive state with hooks (useSignal, useComputed, etc.)
• Set up side effects with useEffect
• Access widget properties via the props getter
• Create the widget builder function

Parameters

• context: The BuildContext for this State. Note that you can access widget properties via the props getter instead of context.widget

Returns

A WidgetFunction that will be called on each rebuild triggered by reactive dependencies. The builder should be a pure function that returns a Widget based on the current reactive state.

Example

@override
setup(context) {
  final count = useSignal(0);
  final doubled = useComputed(() => count.value * 2);

  useEffect(() {
    print('Count changed: ${count.value}');
  }, [count.value]);

  // Return the builder function
  return () => Text('Count: ${count.value}, Doubled: ${doubled.value}');
}

Accessing InheritedWidgets

Unlike initState, the setup function can safely access InheritedWidgets:

@override
setup(context) {
  final theme = Theme.of(context);
  final count = useSignal(0);

  return () => Text(
    'Count: ${count.value}',
    style: theme.textTheme.bodyLarge,
  );
}