Flutter - Create dynamic number of texteditingcontrollers - dynamic

Question

I am recreating an app I have previously made in Swift, and on one of my pages we call an API and based on the results, we present the user a dynamic number of textfields to search by different search parameters.
Is there any good way to do this in Dart/Flutter? Since dart doesn't support generating code at runtime, is this even a possibility?

Answer 1

I just modified #Felix's answer with using Map to store TextEditingControllers instead of list. I think its easy to call textEditingControllers with key value pairs.
Modified code block;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: "MyHomePage",
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(
title: "MyHomePage",
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
var stringListReturnedFromApiCall = ["first", "second", "third", "fourth", "..."];
// This list of controllers can be used to set and get the text from/to the TextFields
Map<String,TextEditingController> textEditingControllers = {};
var textFields = <TextField>[];
stringListReturnedFromApiCall.forEach((str) {
var textEditingController = new TextEditingController(text: str);
textEditingControllers.putIfAbsent(str, ()=>textEditingController);
return textFields.add( TextField(controller: textEditingController));
});
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: SingleChildScrollView(
child: new Column(
children:[
Column(children: textFields),
RaisedButton(
child: Text("Print Values"),
onPressed: (){
stringListReturnedFromApiCall.forEach((str){
print(textEditingControllers[str].text);
});
})
]
)));
}
}
when you write something to textfields and hit to print button results ;
flutter: first controller text
flutter: second controller text
flutter: third controller text
flutter: fourth controller text
flutter: so on .......

Answer 2

More or less as #Günter Zöchbauer mentioned, you can just build a list of widgets which are nested then in a container.
Here's a simple example:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: "MyHomePage",
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(
title: "MyHomePage",
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
var stringListReturnedFromApiCall = ["first", "second", "third", "fourth", "..."];
// This list of controllers can be used to set and get the text from/to the TextFields
var textEditingControllers = <TextEditingController>[];
var textFields = <TextField>[];
stringListReturnedFromApiCall.forEach((str) {
var textEditingController = new TextEditingController(text: str);
textEditingControllers.add(textEditingController);
return textFields.add(new TextField(controller: textEditingController));
});
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: SingleChildScrollView(
child: new Column(
children: textFields,
)));
}
}
Edit: Added list for TextEditingControllers to interact with all the TextFields

Answer 3

Using list of textEditingControllers instead of map
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
var stringListReturnedFromApiCall = ["first", "second", "third", "fourth", "..."];
List<TextEditingController> textEditingControllers = [];
#override
void initState() {
super.initState();
stringListReturnedFromApiCall.forEach((String str) {
var textEditingController = TextEditingController(text: str);
textEditingControllers.add(textEditingController);
});
}
#override
void dispose() {
super.dispose();
// dispose textEditingControllers to prevent memory leaks
for (TextEditingController textEditingController in textEditingControllers) {
textEditingController?.dispose();
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('title'),
),
body: ListView.builder(
itemCount: stringListReturnedFromApiCall.length,
itemBuilder: (BuildContext context, int index) {
return Padding(
padding: const EdgeInsets.all(10.0),
child: TextField(
controller: textEditingControllers[index],
),
);
},
),
);
}
}

Answer 4

list that contains your controllers
var myControllers = [];
function called in order to populate myControllers
createControllers() {
myControllers = [];
for (var i = 0; i < your_items.length; i++) {
myControllers.add(TextEditingController());
}
}
init createKeys in your statefullwidget
use it like this, for example in listview builder ;
TextField(
controller: myControllers[index],
),

Answer 5

May be this can help you or other's as well.
createFieldsList(context) {
thirdStepUserRegistration.value.forEach((key, value) { //// This line will loop all your data [ValueNotifier<Map<String, dynamic>> thirdStepUserRegistration]
if (!fieldsController.containsKey(key)) {
fieldsController[key] = TextEditingController(); //// This one will create you a list of controllers that u need for your fiels [Map<String, TextEditingController> fieldsController]
fieldsList.add( ////You will be creating a list of widget which is textfields [List<Widget> fieldsList]
Container(
height: 40.0,
margin: EdgeInsets.only(bottom: 10),
width: MediaQuery.of(context).size.width - 100,
child: PrimaryTextFormField( //This is my customize textfield you can create yours
controller: fieldsController[key],
keyboardType: TextInputType.text,
textCapitalization: TextCapitalization.words,
inputFormatters: textFormatter(),
hintText: value,
),
)
);
}
});
}
Column additionalDetails(BuildContext context) {
createFieldsList(context);
return Column( children: fieldsList );
}