flutter registration form example

Example 1: create a validator in flutter

TextFormField(
  // The validator receives the text that the user has entered.
  validator: (value) {
    if (value.isEmpty) {
      return 'Please enter some text';
    }
    return null;
  },
);

Example 2: validator flutter

final passwordValidator = MultiValidator([  
    RequiredValidator(errorText: 'password is required'),  
    MinLengthValidator(8, errorText: 'password must be at least 8 digits long'),  
    PatternValidator(r'(?=.*?[#?!@$%^&*-])', errorText: 'passwords must have at least one special character')  
 ]);  
  
  String password;  
  
  Form(  
    key: _formKey,  
    child: Column(children: [  
      TextFormField(  
        obscureText: true,  
        onChanged: (val) => password = val,  
        // assign the the multi validator to the TextFormField validator  
        validator: passwordValidator,  
      ),  
  
      // using the match validator to confirm password  
      TextFormField(  
        validator: (val) => MatchValidator(errorText: 'passwords do not match').validateMatch(val, password),  
      )  
    ]),  
  );

Example 3: registration in flutter

onPressed: () async {
                  setState(() {
                    spooner = true;
                  });
                  try {
                    final newUser = await _auth.createUserWithEmailAndPassword(
                        email: email, password: password);
                    if (newUser != null) {
                      Navigator.pushNamed(context, ChatScreen.id);
                    }
                    setState(() {
                      spooner = false;
                    });
                  } catch (e) {
                    print(e);
                  }