A TextEditingController was used after being disposed. Called a reusable entry field class where i am passing this controller

Question

I have created a reusable field that is called to display different fields in a form in different screen in my app i have also passed a controller however when dispose the controller it shows this error and if i go back to the same form screen it crashes.

class EntryField extends StatefulWidget {
  @override
  _EntryFieldState createState() => _EntryFieldState();
  final String title;
  final TextEditingController controller;
  final TextInputType inputType;
  final FilteringTextInputFormatter filter;
  final hintText;
  EntryField({@required this.title,this.hintText,@required this.controller,@required this.inputType,@required this.filter});
}
class _EntryFieldState extends State<EntryField> {
  @override
  void dispose() {
    widget.controller.dispose();
    print("anything");
    super.dispose();
  }
  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.symmetric(vertical: 10),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text(
              this.widget.title,
              style: GoogleFonts.quicksand(
                fontSize: 18,
              )
          ),
          SizedBox(
            height: 10,
          ),
          TextFormField(
            controller: this.widget.controller,
            keyboardType: this.widget.inputType,
            inputFormatters: <TextInputFormatter>[
              this.widget.filter,
            ],
            validator: (value){
              if(value.isEmpty){
                return "${this.widget.title} is a Required Field";
              }
              return null;
            },
            decoration: InputDecoration(
              hintText: this.widget.hintText,
              border: InputBorder.none,
              fillColor: Color(0xfff3f3f4),
              filled: true,
              errorBorder: new OutlineInputBorder(
                borderSide: new BorderSide(color: Colors.red),
              ),
              errorStyle: TextStyle(
                fontSize: 15,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

and in this class i am passing it field values

final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
final _serviceTitleController = TextEditingController();
final _serviceCategoryController = TextEditingController();
final _servicePriceController = TextEditingController();
ToastErrorMessage _error = ToastErrorMessage();
ToastValidMessage _valid = ToastValidMessage();

class AddServices extends StatefulWidget {
  @override
  _AddServicesState createState() => _AddServicesState();
}

class _AddServicesState extends State<AddServices> {

  int currentIndex;
  String _cityName;
  final WorkshopServiceQueries _add = WorkshopServiceQueries();
  final _firebaseUser = FirebaseAuth.instance.currentUser;

  @override
  void initState() {
    cityName();
    super.initState();
    currentIndex = 0;
  }
  @override
  void dispose() {
    print("hello");
    super.dispose();
  }
  void clearControllerText(){
    _serviceTitleController.clear();
    _serviceCategoryController.clear();
    _servicePriceController.clear();

  }

  Future cityName() async{
   _cityName = await _add.getWorkshopCityName();
  }

  changePage(int index) {
    setState(() {
      currentIndex = index;
    });
  }
  validateFields() async{

    final ValidateWorkshopServices service = ValidateWorkshopServices();
    final int _price = int.tryParse(_servicePriceController.text.trim());
    if(!service.validateServiceCategory(_serviceCategoryController.text.trim()) && !service.validateServiceTitle(_serviceTitleController.text.trim()) && !service.validateServicePrice(_price)){
      _error.errorToastMessage(errorMessage: "Enter Valid Data in Each Field");
    }
    else if(!service.validateServiceCategory(_serviceCategoryController.text.trim())){
      _error.errorToastMessage(errorMessage: "Service Category Must Only contain Alphabets");
    }
    else if(!service.validateServiceTitle(_serviceTitleController.text.trim())){
      _error.errorToastMessage(errorMessage: "Service Title Must Only contain Alphabets");
    }
    else if(!service.validateServicePrice(_price)){
      _error.errorToastMessage(errorMessage: "Service Price must be less than or equal to 2000");
    }
    else{
     await addService(_price);
    }
  }
  Future<void> addService(int price) async{
  try {

      Services data = Services(title: _serviceTitleController.text.trim(), category: _serviceCategoryController.text.trim(), price: price, workshopCity: _cityName, workshopId: _firebaseUser.uid);
      await _add.addWorkshopService(data);
      if(WorkshopServiceQueries.resultMessage == WorkshopServiceQueries.completionMessage){
        _valid.validToastMessage(validMessage: WorkshopServiceQueries.resultMessage);
        clearControllerText();
        Future.delayed(
          new Duration(seconds: 2),
              (){
            Navigator.pop(context);
          },
        );
      }
      else{
        _error.errorToastMessage(errorMessage: WorkshopServiceQueries.resultMessage);
      }
    }catch(e){
       _error.errorToastMessage(errorMessage: e.toString());
    }
}

  @override
  Widget build(BuildContext context) {

    final height = MediaQuery.of(context).size.height;
    int _checkboxValue;
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text(
            'BIKERSWORLD',
            style: GoogleFonts.quicksand(
              color: Colors.white,
              fontSize: 18,
            ),
          ),
          backgroundColor: Color(0XFF012A4A),
            leading: IconButton(icon:Icon(Icons.arrow_back, color: Colors.orange,),
              onPressed:() => Navigator.pop(context),
            )
        ),
        body: Container(
          height: height,
          child: Stack(
            children: <Widget>[
              Container(
                padding: EdgeInsets.symmetric(horizontal: 20),
                child: SingleChildScrollView(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      SizedBox(height: 30,),
                      _title(),
                      SizedBox(height: 40),
                      _addServicesWidget(),
                      SizedBox(height: 20),
                      FlatButton(
                      child: Container(
                        padding: EdgeInsets.symmetric(vertical: 15),
                        alignment: Alignment.center,
                        decoration: BoxDecoration(
                            borderRadius: BorderRadius.all(Radius.circular(5)),
                            boxShadow: <BoxShadow>[
                              BoxShadow(
                                  color: Colors.grey.shade200,
                                  offset: Offset(2, 4),
                                  blurRadius: 5,
                                  spreadRadius: 2)
                            ],
                            gradient: LinearGradient(
                                begin: Alignment.centerLeft,
                                end: Alignment.centerRight,
                                colors: [Color(0xfffbb448), Color(0xfff7892b)])),
                        child: Text(
                          'Register Now',
                          style: GoogleFonts.krub(
                            fontSize: 18,
                            color: Colors.white,
                          ),
                        ),
                      ),
                      onPressed: (){
                        if(!_formKey.currentState.validate()){
                          return;
                        }
                        else{
                          validateFields();
                        }
                      },
                    ),
                      SizedBox(height: 20),

                    ],
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}
Widget _addServicesWidget() {
  return Form(
    key: _formKey,
    autovalidateMode: AutovalidateMode.disabled,
    child: Column(
      children: <Widget>[
        EntryField(title: "Category",hintText: 'Mechanical',controller: _serviceCategoryController,inputType: TextInputType.text,filter: FilteringTextInputFormatter.allow(RegExp("[a-zA-Z ]"))),
        SizedBox(height:15,),
        EntryField(title: "Title",hintText: 'wheel barring',controller: _serviceTitleController,inputType: TextInputType.text,filter: FilteringTextInputFormatter.allow(RegExp("[a-zA-Z ]"))),
        SizedBox(height:15,),
        EntryField(title: "Price",hintText: 'price < 2000',controller: _servicePriceController,inputType: TextInputType.number,filter:FilteringTextInputFormatter.digitsOnly),
      ],
    ),
  );
}

Why are you disposing of the controller in that Class and not on the Class where you created it originally? — J. S., Mar 18 '21 at 09:54
i am disposing the controller in the reuseable widget which class i call again and again to generate different fields. — Informative Programmer, Mar 18 '21 at 11:10
i also tried to dispose in the class where i am calling this reuseable class but still shows same error — Informative Programmer, Mar 18 '21 at 11:11
I'm sorry, but you have to give us a smaller, reproducible, piece of code for us to try to reproduce your issue and help you. As it is, you have multiple things we don't have access to. — J. S., Mar 18 '21 at 11:25
i have shared the whole class where i am using these reuseable fields — Informative Programmer, Mar 18 '21 at 11:38

score 3 · Answer 1 · answered Mar 18 '21 at 12:02

3

You shouldn't dispose the controller from within your widget, since you are creating it outside the widget and passing a reference to it into the widget.

It looks like your controllers are created in the global scope - if so, and if they are intended to be used throughout the lifetime of the app, you shouldn't dispose them.

So either

don't dispose the controllers if they are globals
or create and dispose them from the same "owner" object

answered Mar 18 '21 at 12:02

Magnus

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This I one class where I am calling this reusable entry field class but there are many forms in my app where I am using this class should I dispose it or not – Informative Programmer Mar 18 '21 at 13:31
@InformativeProgrammer You should dispose it when you no longer need it. After you have disposed it, if you need to use it again, you would need to create a new controller. So if you intend to use the same controller during the entire app, then there is no need to dispose of it. – Magnus Mar 18 '21 at 19:15
For different screens containing forms I am using different controllers if I try to dispose of them then it show the error – Informative Programmer Mar 19 '21 at 09:21
would that mean that in the onClose method inside getxController we dont dispose the controller. If thats the case i tried it and im still getting the same error when using Get.back – LearnFlutter Jun 02 '22 at 10:58

score 3 · Answer 2 · answered May 15 '22 at 03:39

for future comers, in my case i was using dispose twice for the same controller:

//error
void dispose() {
     myController.dispose();
     myController.dispose();
     super.dispose();
  }

//ok
void dispose() {
     myController.dispose();
     super.dispose();
  }

A TextEditingController was used after being disposed. Called a reusable entry field class where i am passing this controller

2 Answers2