avoid_returning_widgets

v0.4.0 Warning Widget Best Practices

This rule warns when a function, method, or getter returns a Widget. Building widgets inside helper methods is a common Flutter anti-pattern because the framework cannot optimize rebuilds for code that lives outside of a proper widget class.

Why use this rule

When you extract UI into a _buildHeader() method instead of a _Header widget class, Flutter treats the entire parent widget as a single unit. It cannot skip rebuilding the header when only something else changed. Proper widget classes give Flutter the information it needs to do fine-grained rebuilds, which directly improves performance in complex UIs.

See also: Flutter performance best practices

Don’t

class MyScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(children: [_buildHeader(), _body]);
  }

  // Helper method returning a widget
  Widget _buildHeader() => const Text('Header');

  // Getter returning a widget
  Widget get _body => const Text('Body');
}

Do

class MyScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const Column(children: [_Header(), _Body()]);
  }
}

class _Header extends StatelessWidget {
  const _Header();

  @override
  Widget build(BuildContext context) => const Text('Header');
}

class _Body extends StatelessWidget {
  const _Body();

  @override
  Widget build(BuildContext context) => const Text('Body');
}

Configuration

To disable this rule:

plugins:
  many_lints:
    diagnostics:
      avoid_returning_widgets: false