flutter form field validator classes code example
Example 1: create a validator in flutter
ElevatedButton(
onPressed: () {
// Validate returns true if the form is valid, otherwise false.
if (_formKey.currentState.validate()) {
// If the form is valid, display a snackbar. In the real world,
// you'd often call a server or save the information in a database.
Scaffold
.of(context)
.showSnackBar(SnackBar(content: Text('Processing Data')));
}
},
child: Text('Submit'),
);
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),
)
]),
);