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), ) ]), );