no_logic_in_create_state.md

Pattern: Use of logic in createState()

Issue: -

Description

Implementations of createState() should return a new instance of a State object and do nothing more. Since state access is preferred via the widget field, passing data to State objects using custom constructor parameters should also be avoided and so further, the State constructor is required to be passed no arguments.

Example of incorrect code:

MyState global;

class MyStateful extends StatefulWidget {
 @override
 MyState createState() {
  global = MyState();
  return global;
 } 
}

class MyStateful extends StatefulWidget {
 @override
 MyState createState() => MyState()..field = 42;
}

class MyStateful extends StatefulWidget {
 @override
 MyState createState() => MyState(42);
}

Example of correct code:

class MyStateful extends StatefulWidget {
 @override
 MyState createState() {
  return MyState();
 }
}

Further Reading

• Linter for Dart - no_logic_in_create_state