Flutter - Checking Validation of TextFormField

Question

Hi im new to flutter.

Im using TextFormField widget to validate the input if the textformfield is empty and wrapping it with GlobalKey Form widget.

Can i ask if its possible just only check atleast one field is not empty then its valid.

TextField A = empty & TextField B = not empty:: valid
TextField A = not empty & TextField B = empty:: valid
TextField A = empty & TextField B = empty:: not valid

This is the situation there are two textformfield A and textformfield B atleast one must not be empty so it could be A or B. But if both is empty then the user must fill one textfield. My objective is all my textformfield has a validation but its okay if atleast one is filled or not empty.

final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

                Form(
                key: _formKey,
                child: Column(children: [
                  TextFormField(validator: (value) {
                    if (value.isEmpty) {
                      return "Please Fill";
                    }
                  }),
                  TextFormField(validator: (value) {
                    if (value.isEmpty) {
                      return "Please Fill";
                    }
                  }),
                  RaisedButton(
                    child: Text("Submit"),
                    onPressed: () async {
                        if (_formKey.currentState.validate()) {
                          return;
                        }
                        _formKey.currentState.save();
                        //Some Codes
                      },
                  )
                ]),
              ),

I was planing to change it to TextField widget and use setState({}) to check if atleast 1 got filled but i dont want to use setState. Is there a way to solve my problem?. Thanks

Answer 1

Try this:

final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

                Form(
                key: _formKey,
                child: Column(children: [
                  TextFormField(validator: (value) {
                    if (value.isEmpty) {
                      return "Please Fill";
                    }
                    return null;
                  }),
                  TextFormField(validator: (value) {
                    if (value.isEmpty) {
                      return "Please Fill";
                    }
                    return null;
                  }),
                  RaisedButton(
                    child: Text("Submit"),
                    onPressed: () async {
                        if (_formKey.currentState.validate()) {
                          // If the form is valid, display a Snackbar.
                            Scaffold.of(context).showSnackBar(SnackBar(content: Text('Processing Data')));
                        }
                        _formKey.currentState.save();
                        //Some Codes
                      },
                  )
                ]),
              ),