How to control null when bulding widget - flutter

Question

Can you tell me how can I include the condition for Image.file on the following page? I would like to build it only when controller.image is not null.
I got an error:
The following NoSuchMethodError was thrown building Container(padding: EdgeInsets.all(32.0)):
The method '[]' was called on null.
Receiver: null
Tried calling:
when I first redirect to this page (and controller.image is null):
class HomePage extends GetView<HomeController> {
final myController1 = TextEditingController();
final myController2 = TextEditingController();
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Grobonet'),
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
children: <Widget>[
TextField(
controller: myController1,
decoration: InputDecoration(
border: InputBorder.none,
hintText: 'Nazwisko'),
),
TextField(
controller: myController2,
decoration: InputDecoration(
border: InputBorder.none,
hintText: 'Miejscowosc'),
),
IconButton(
icon: Icon(
Icons.add,
size: 30,
),
onPressed: () =>
Get.toNamed(
AppRoutes.PICK_IMAGE
),
color: Colors.pink,
),
IconButton(
icon: Icon(
Icons.save_outlined,
size: 30,
),
/*onPressed: () =>
Get.toNamed(
AppRoutes.PICK_IMAGE
),*/
color: Colors.pink,
),
Container(
padding: EdgeInsets.all(32),
child: GetBuilder<HomeController>(
builder: (_) {
return Image.file(controller.image);
},
),
),
]
),
),
);
}
}
Controller:
class HomeController extends GetxController {
final image = Get.arguments['image'];
final file_loaded = Get.arguments['file_loaded'];
}

Answer 1

You can use collection-if. Just add if (controller.image != null) like so:
if (controller?.image != null)
Container(
padding: EdgeInsets.all(32),
child: GetBuilder<HomeController>(
builder: (_) {
return Image.file(controller.image);
},
),
),

Answer 2

Use Get your arguments on the controller's onInit() method:
class HomeController extends GetxController {
final File image;
final File file_loaded;
onInit(){
image = Get.arguments['image'];
file_loaded = Get.arguments['file_loaded'];
}
}
In this way, you don't need to perform additional null checks except Get.arguments is actually null.
Update
And you also need to update your view like this:
Container(
padding: EdgeInsets.all(32),
child: GetBuilder<HomeController>(
builder: (_) {
return Image.file(_.image); // not return Image.file(controller.image);
// _ here is the instance of HomeController given by the GetBuilder
},
),
),
Update 2
As you mentioned in the comments, you want to send data to a previously opened page (HomePage) from a second page (OCRDetailsPage). Then you don't need to pass arguments. You can get the HomeController instance in your OCRDetailsPage with Get.find() and set the variables and update the state like:
class OCRDetailsPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
final OCRDetailsController controller = Get.find();
return Scaffold(
appBar: AppBar(title: Text('OCR Details Page')),
body: Center(
child: FlatButton(
color: Colors.blue,
child: Icon(Icons.save_outlined),
onPressed: () {
final HomeController homeController = Get.find();
homeController.ocr_text = controller.text;
homeController.update();
Get.toNamed(
AppRoutes.HOME,
);
}),
),
);
}
}