Contents
Contents

Sort child properties last in widget instance creations.

This rule is available as of Dart 2.4.0.

Rule sets: flutter

This rule has a quick fix available.

Details

#

Sort child properties last in widget instance creations. This improves readability and plays nicest with UI as Code visualization in IDEs with UI as Code Guides in editors (such as IntelliJ) where Properties in the correct order appear clearly associated with the constructor call and separated from the children.

BAD:

dart
return Scaffold(
  appBar: AppBar(
    title: Text(widget.title),
  ),
  body: Center(
    child: Column(
      children: <Widget>[
        Text(
          'You have pushed the button this many times:',
         ),
        Text(
          '$_counter',
          style: Theme.of(context).textTheme.display1,
         ),
      ],
      mainAxisAlignment: MainAxisAlignment.center,
    ),
    widthFactor: 0.5,
  ),
  floatingActionButton: FloatingActionButton(
    child: Icon(Icons.add),
    onPressed: _incrementCounter,
    tooltip: 'Increment',
  ),
);

GOOD:

dart
return Scaffold(
  appBar: AppBar(
    title: Text(widget.title),
  ),
  body: Center(
    widthFactor: 0.5,
    child: Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Text(
          'You have pushed the button this many times:',
         ),
        Text(
          '$_counter',
          style: Theme.of(context).textTheme.display1,
         ),
      ],
    ),
  ),
  floatingActionButton: FloatingActionButton(
    onPressed: _incrementCounter,
    tooltip: 'Increment',
    child: Icon(Icons.add),
  ),
);

Exception: It's allowed to have parameter with a function expression after the child property.

Usage

#

To enable the sort_child_properties_last rule, add sort_child_properties_last under linter > rules in your analysis_options.yaml file:

analysis_options.yaml
yaml
linter:
  rules:
    - sort_child_properties_last