Flutter: Avoiding the Top Mistakes

Widgets and Layout

• Avoid using SizedBox to artificially constrain size. Use MainAxisSize.min instead.
• Avoid deeply nesting Flex widgets like Column and Row. Extract contents to separate widgets.
• Extract repeating UI components into separate widgets early for better testability and reusability.
• Constrain child widget size to avoid RenderFlex overflow, for example with Expanded or Flexible.
• Provide layout information to widgets to avoid 'RenderBox was not laid out' errors.
• Constraint scrollable widgets like ListView when placed inside Column to avoid unbounded height.
• Use Expanded or SizedBox to constrain TextFormField inside Row to avoid unbounded width.
• Ensure parent widget is compatible with ParentDataWidget children.
• Don't call setState in build method, for example when showing Dialog, as it can lead to errors.
• Use OrientationBuilder to handle UI issues when orientation changes.

Architecture and Organization

• Decouple UI components from business logic by using dependency injection, for cleaner code.
• Use state management solutions like Provider early on for more complex apps.
• Learn basics of Android and iOS development to better understand Flutter.
• Implement features yourself before using packages to better learn fundamentals.
• Separate concerns following best practices for clean, maintainable code.
• Use named routes for clearer navigation instead of Navigator.push().

Testing and Quality

• Write tests like unit, widget, and integration tests to ensure app works as expected.
• Carefully handle errors to avoid crashes. Validate input and use catchError.
• Use Dart profiler to optimize performance and avoid lag and delays.
• Learn about Flutter widget lifecycles to avoid issues like not disposing controllers properly.
• Remember to fully restart app if bugs appear after adding a native plugin, as hot reload won't update native code.

Best Practices

• Use linter package for consistent, clean code. Enforce good practices.
• Extract reusable UI into widgets to optimize performance and reduce rebuilds.
• Ask questions! The Flutter community is helpful and wants to see you succeed.