SetupBuilder class

A convenience widget that uses a builder function for setup.

SetupBuilder provides the simplest way to use Jolt's setup API without creating a custom widget class. It's ideal for quick prototyping, simple components, or inline reactive widgets.

When to Use

Use SetupBuilder when:

• Prototyping or experimenting with reactive state
• Creating simple, self-contained components
• You don't need custom widget properties
• The component logic is straightforward

Use SetupWidget subclass when:

• You need custom properties (title, count, callback, etc.)
• Building reusable components with clear APIs
• The component is complex or will be used in multiple places
• You want better IDE support and type checking for properties

Example

// Simple counter - no custom properties needed
SetupBuilder(
  setup: (context) {
    final count = useSignal(0);

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

    return () => Column(
      children: [
        Text('Count: ${count.value}'),
        ElevatedButton(
          onPressed: () => count.value++,
          child: const Text('Increment'),
        ),
      ],
    );
  },
)

Comparison with SetupWidget

// SetupBuilder: For simple widgets without custom properties
SetupBuilder(
  setup: (context) {
    final count = useSignal(0);
    return () => Text('Count: ${count.value}');
  },
)

// SetupWidget: For reusable widgets with custom properties
class Counter extends SetupWidget<Counter> {
  final int initialValue;
  final String label;

  const Counter({
    super.key,
    required this.initialValue,
    required this.label,
  });

  @override
  setup(context, props) {
    // Access reactive props through props parameter
    final count = useSignal(props().initialValue);

    // React to prop changes
    final displayText = useComputed(() =>
      '${props().label}: ${count.value}'
    );

    return () => Text(displayText.value);
  }
}