Flutter: Best way to get all values in a form - flutter

Question

I'm making a data collection app which has multiple TextFields, like more than 12. I'm using a Form key to validate all of them. I want values of all the text fields so I can save them to firestore. How do I do this? Here's my code:
import 'package:flutter/material.dart';
class MainForm extends StatefulWidget {
#override
_MainFormState createState() => _MainFormState();
}
class _MainFormState extends State<MainForm> {
final _formKey = GlobalKey<FormState>();
#override
Widget build(BuildContext context) {
return Center(
child: SingleChildScrollView(
child: Form(
key: _formKey,
child: Column(
children: <Widget>[
Text('Enter information about PG Owner'),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextField(
autofocus: true,
textCapitalization: TextCapitalization.words,
textAlignVertical: TextAlignVertical.center,
onTap: () {},
decoration: InputDecoration(
prefixIcon: Icon(Icons.face),
labelText: 'Enter Name of Owner',
border: OutlineInputBorder()),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (value) {
if (value.length < 15) {
return 'Address seems very short!';
}
return null;
},
keyboardType: TextInputType.text,
decoration: InputDecoration(
prefixIcon: Icon(Icons.room),
labelText: 'Enter full address of Owner',
border: OutlineInputBorder()),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
keyboardType: TextInputType.number,
validator: (value) {
if (value.length < 9) {
return 'Phone number must be 9 digits or longer';
}
return null;
},
decoration: InputDecoration(
prefixIcon: Icon(Icons.phone),
labelText: 'Phone number of Owner',
border: OutlineInputBorder()),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (value) {
if (value.isEmpty) {
return 'Please enter a valid email address';
}
if (!value.contains('#')) {
return 'Email is invalid, must contain #';
}
if (!value.contains('.')) {
return 'Email is invalid, must contain .';
}
return null;
},
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
prefixIcon: Icon(Icons.mail_outline),
labelText: 'Enter Email',
border: OutlineInputBorder()),
),
),
)
],
),
),
),
);
}
}
Update: I know that proper way (I've read the docs) of getting values from a TextField is by creating a controller. But, In my case there are 14 TextFields which requires me to create 14 controllers. Is there a better way of doing this?

Answer 1

You can use something like this in the following code:
_formKey.currentState.save(); calls the onSaved() on each textFormField items, which assigns the value to all the fields and you can use them as required. Try using the _formKey.currentState.save(); just after _formKey.currentState.validate() is evaluated as true.
The form code looks like this:
String contactNumber;
String pin;
return Form(
key: _formKey,
child: Column(
children: <Widget>[
TextFormField(
onSaved: (String value){contactNumber=value;},
keyboardType: TextInputType.phone,
inputFormatters: [WhitelistingTextInputFormatter.digitsOnly],
maxLength: 10,
decoration: InputDecoration(
labelText: "Enter Your Mobile Number",
hintText: "Number",
icon: Icon(Icons.phone_iphone)),
validator: (value) {
if (value.isEmpty || value.length < 10) {
return 'Please Enter 10 digit number';
}
return null;
},
),
TextFormField(
onSaved: (String value){pin=value;},
keyboardType: TextInputType.phone,
inputFormatters: [WhitelistingTextInputFormatter.digitsOnly],
maxLength: 10,
decoration: InputDecoration(
labelText: "Enter Your PIN",
hintText: "Number",
icon: Icon(Icons.lock)),
validator: (value) {
if (value.isEmpty || value.length < 6) {
return 'Please Enter 6 digit PIN';
}
return null;
},
),
Padding(
padding: const EdgeInsets.symmetric(vertical: 16.0),
child: RaisedButton(
color: Colors.black,
textColor: Colors.white,
onPressed: () {
if (_formKey.currentState.validate()) {
***_formKey.currentState.save();***
bloc.loginUser(contactNumber, pin);
}
},
child: Text('Login' /*style: TextStyle(fontSize: 30),*/)),
)
],
),
);

Answer 2

Using controller in TextFormField, you can get value of the TextFormField.
TextEditingController emailEditingController = TextEditingController();
TextFormField(
controller: emailEditingController,
validator: (value) {
if (value.isEmpty) {
return 'Please enter a valid email address';
}
if (!value.contains('#')) {
return 'Email is invalid, must contain #';
}
if (!value.contains('.')) {
return 'Email is invalid, must contain .';
}
return null;
},
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
prefixIcon: Icon(Icons.mail_outline),
labelText: 'Enter Email',
border: OutlineInputBorder()),
);
Get Value like:
String email=emailEditingController.text;
Updated Answer
Get value by using onSubmitted
onSubmitted: (String value){email=value;},

Answer 3

I am not satisfied with how Flutter make you handle the form values yourself, you need to create a TextEditingController instance for each field, assign it to the controller and remember to dispose all of them manually. This leads to a lot of boilerplate code and makes it more error-prone:
final _formKey = GlobalKey<FormState>();
final controller1 = TextEditingController();
final controller2 = TextEditingController();
final controller3 = TextEditingController();
#override
void dispose() {
super.dispose();
controller1.dispose();
controller2.dispose();
controller3.dispose();
}
#override
Widget build(BuildContext context) {
return Form(
key: _formKey,
child: Column(children: [
TextFormField(controller: controller1),
TextFormField(controller: controller2),
TextFormField(
controller: controller3,
validator: (value) {
if (value == null || value.isEmpty) {
return 'Please enter some text';
}
return null;
},
),
ElevatedButton(
onPressed: () {
if (_formKey.currentState!.validate()) {
final value1 = controller1.text;
final value2 = controller2.text;
final value3 = controller3.text;
// do something with the form data
}
},
child: const Text('Submit'),
),
]),
);
}
A much less cumbersome way is to use the flutter_form_builder package and replace TextFormField with the FormBuilderTextField widget which is a wrapper of the old plain TextField. You can see all of the supported input widgets here.
All you need to do now is to specify the name of each field in your form, and access it in _formKey.currentState?.value. See the example below:
final _formKey = GlobalKey<FormBuilderState>();
#override
Widget build(BuildContext context) {
return FormBuilder(
key: _formKey,
child: Column(children: [
FormBuilderTextField(name: 'field1'),
FormBuilderTextField(name: 'field2'),
FormBuilderTextField(
name: 'field3',
validator: FormBuilderValidators.required(
context,
errorText: 'Please enter some text',
),
),
ElevatedButton(
onPressed: () {
_formKey.currentState.save();
if (_formKey.currentState!.validate()) {
final formData = _formKey.currentState?.value;
// formData = { 'field1': ..., 'field2': ..., 'field3': ... }
// do something with the form data
}
},
child: const Text('Submit'),
),
]),
);
}

Answer 4

You can use flutter_form_bloc, you don't need to create any TextEditingController and can separate the Business Logic from the User Interface, in addition to offering other advantages.
dependencies:
flutter_bloc: ^0.21.0
form_bloc: ^0.4.1
flutter_form_bloc: ^0.3.0
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_form_bloc/flutter_form_bloc.dart';
import 'package:form_bloc/form_bloc.dart';
void main() => runApp(MaterialApp(home: MainForm()));
class MainFormBloc extends FormBloc<String, String> {
final nameField = TextFieldBloc();
final addressField = TextFieldBloc(validators: [
(value) => value.length < 15 ? 'Address seems very short!' : null,
]);
final phoneNumberField = TextFieldBloc(validators: [
(value) =>
value.length < 9 ? 'Phone number must be 9 digits or longer' : null,
]);
final emailField = TextFieldBloc(validators: [Validators.email]);
#override
List<FieldBloc> get fieldBlocs => [
nameField,
addressField,
phoneNumberField,
emailField,
];
#override
Stream<FormBlocState<String, String>> onSubmitting() async* {
// This method is called when you call [mainFormBloc.submit]
// and each field bloc have a valid value.
// And you can save them in firestore.
print(nameField.value);
print(addressField.value);
print(phoneNumberField.value);
print(emailField.value);
yield currentState.toSuccess('Data saved successfully.');
// yield `currentState.toLoaded()` because
// you can't submit if the state is `FormBlocSuccess`.
// In most cases you don't need to do this,
// because you only want to submit only once.
yield currentState.toLoaded();
}
}
class MainForm extends StatelessWidget {
#override
Widget build(BuildContext context) {
return BlocProvider<MainFormBloc>(
builder: (context) => MainFormBloc(),
child: Builder(
builder: (context) {
final formBloc = BlocProvider.of<MainFormBloc>(context);
return Scaffold(
appBar: AppBar(title: Text('Main Form')),
body: FormBlocListener<MainFormBloc, String, String>(
onSuccess: (context, state) {
Scaffold.of(context).showSnackBar(
SnackBar(
content: Text(state.successResponse),
backgroundColor: Colors.green,
),
);
},
onSubmissionFailed: (context, state) {
Scaffold.of(context).showSnackBar(
SnackBar(
content: Text('Some fields have invalid data.'),
backgroundColor: Colors.red,
),
);
},
child: ListView(
children: <Widget>[
TextFieldBlocBuilder(
textFieldBloc: formBloc.nameField,
padding: const EdgeInsets.all(8.0),
autofocus: true,
textCapitalization: TextCapitalization.words,
textAlignVertical: TextAlignVertical.center,
decoration: InputDecoration(
prefixIcon: Icon(Icons.face),
labelText: 'Enter Name of Owner',
border: OutlineInputBorder()),
),
TextFieldBlocBuilder(
textFieldBloc: formBloc.addressField,
padding: const EdgeInsets.all(8.0),
keyboardType: TextInputType.text,
decoration: InputDecoration(
prefixIcon: Icon(Icons.room),
labelText: 'Enter full address of Owner',
border: OutlineInputBorder()),
),
TextFieldBlocBuilder(
textFieldBloc: formBloc.phoneNumberField,
padding: const EdgeInsets.all(8.0),
keyboardType: TextInputType.number,
decoration: InputDecoration(
prefixIcon: Icon(Icons.phone),
labelText: 'Phone number of Owner',
border: OutlineInputBorder()),
),
TextFieldBlocBuilder(
textFieldBloc: formBloc.emailField,
padding: const EdgeInsets.all(8.0),
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
prefixIcon: Icon(Icons.mail_outline),
labelText: 'Enter Email',
border: OutlineInputBorder()),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: RaisedButton(
onPressed: formBloc.submit,
child: Center(child: Text('SUBMIT')),
),
),
],
),
),
);
},
),
);
}
}

Answer 5

I came here from a similar search. All the answers found did not satisfy my need, hence I wrote a custom solution.
form key
final _signUpKey = GlobalKey<FormState>();
declare your TextEditingController
final Map<String, TextEditingController> sigUpController = {
'firstName': TextEditingController(),
'lastName': TextEditingController(),
'email': TextEditingController(),
'phone': TextEditingController(),
'password': TextEditingController(),
};
Pass controller to TextFormField like this
Form(
key: _signUpKey,
child: Column(
children: [
TextFormField(
controller: sigUpController['firstName'],
validator: validator,
autofocus: autofocus,
keyboardType: TextInputType.text,
style: const TextStyle(
fontSize: 14,
),
onTap: onTap,
onChanged: onChanged,
inputFormatters: [
FilteringTextInputFormatter.allow(
RegExp(r"[a-zA-Z]+|\s"),
),
],
),
// define the other TextFormField here
TextButton(
onPressed: () {
if (!_signUpKey.currentState!.validate()) {
return;
}
// To get data I wrote an extension method bellow
final data = sigUpController.data();
print('data: $data'); // data: {firstName: John, lastName: Doe, email: example#email.com, phone: [phone], password: password}
},
child: const Text('submit'),
)
],
),
);
Extension method to get data from Map<String, TextEditingController>
extension Data on Map<String, TextEditingController> {
Map<String, dynamic> data() {
final res = <String, dynamic>{};
for (MapEntry e in entries) {
res.putIfAbsent(e.key, () => e.value?.text);
}
return res;
}
}

Answer 6

Try using this flutter package flutter_form_builder, it will help you from repeating yourself by creating multiple controllers for each form field. In addition to that, it will help you in validating the form, and updating the form with simplicity by using only a simple form key to control the entire form.