having trouble with Flutter null safety, database object refuses to initialize - flutter

Question

I have been trying to implement a simple To Do app without providers (for the course's sake) to advance in the course at the pace the instructor intended. But I cannot seem to find a solution for this small problem..
in the below code, the variable database does not want to be initialized whatsoever. The getData() method that's supposed to retrieve data (query) doesn't initialize the variable database even if I call it in createDatabase() in initState() It keeps giving the following errors:
''' I/flutter ( 5171): error LateInitializationError: Field 'database' has not been initialized. during open, closing...
E/flutter ( 5171): [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: LateInitializationError: Field 'database' has not been initialized.
'''
import 'package:intl/intl.dart';
import 'package:sqflite/sqflite.dart';
import 'package:to_do_app/modules/todo_app/archived/archived_screen.dart';
import 'package:to_do_app/modules/todo_app/done/done_screen.dart';
import 'package:to_do_app/modules/todo_app/tasks/tasks_screen.dart';
class HomeLayout extends StatefulWidget {
const HomeLayout({ Key? key }) : super(key: key);
#override
State<HomeLayout> createState() => _HomeLayoutState();
}
class _HomeLayoutState extends State<HomeLayout> {
int currentIndex = 0;
List<String> titles = [
'Tasks',
'Done Tasks',
'Archived Tasks',
];
List<Map> tasks = [];
late Database database;
var scaffoldKey = GlobalKey<ScaffoldState>();
bool isOpen = false;
IconData fabIcon = Icons.edit;
var titleController = TextEditingController();
var dateController = TextEditingController();
var timeController = TextEditingController();
var formKey = GlobalKey<FormState>();
#override
void initState() {
super.initState();
createDatabase();
}
#override
Widget build(BuildContext context) {
List <Widget> screens = [
NewTasksScreen(),
DoneTasksScreen(),
ArchivedTasksScreen()
];
return Scaffold(
key: scaffoldKey,
appBar: AppBar(
title: Text(titles[currentIndex]),
),
floatingActionButton: FloatingActionButton(
onPressed: () {
if(isOpen == false){
isOpen = true;
setState(() {
fabIcon = Icons.add;
});
scaffoldKey.currentState!.showBottomSheet(
(context) => SingleChildScrollView(
child: Padding(
padding: const EdgeInsets.all(20),
child: Form(
key: formKey,
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
TextFormField(
validator: (value){
if(value!.isEmpty){
return 'title must not be empty';
}
},
controller: titleController,
decoration: InputDecoration(
labelText: 'Title',
prefixIcon: Icon(
Icons.title
),
),
),
SizedBox(height: 10),
TextFormField(
onTap: (){
showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime.now(),
lastDate: DateTime(2025)
).then((value) {
dateController.text = DateFormat.yMMMMd().format(value!);
});
},
validator: (value){
if(value!.isEmpty){
return 'date must not be empty';
}
},
controller: dateController,
decoration: InputDecoration(
labelText: 'Date',
prefixIcon: Icon(
Icons.date_range
),
),
),
SizedBox(height: 10),
TextFormField(
onTap: (){
showTimePicker(
context: context,
initialTime: TimeOfDay.now()
).then((value) {
timeController.text = value!.format(context);
});
},
validator: (value){
if(value!.isEmpty){
return 'time must not be empty';
}
},
controller: timeController,
decoration: InputDecoration(
labelText: 'Time',
prefixIcon: Icon(
Icons.timer
),
),
),
],
),
),
),
),
).closed.then(
(value) {
isOpen = false;
}
);
} else {
if (formKey.currentState!.validate()) {
insertIntoDatabase(
title: titleController.text,
date: dateController.text,
time: timeController.text
).then((value) {
Navigator.pop(context);
isOpen = false;
setState(() {
fabIcon = Icons.edit;
});
});
}
}
},
child: Icon(
fabIcon
),
),
bottomNavigationBar: BottomNavigationBar(
elevation: 20,
type: BottomNavigationBarType.fixed,
currentIndex: currentIndex,
items: [
BottomNavigationBarItem(
icon: Icon(
Icons.task_alt
),
label: 'new tasks'
),
BottomNavigationBarItem(
icon: Icon(
Icons.done
),
label: 'done tasks'
),
BottomNavigationBarItem(
icon: Icon(
Icons.archive_outlined
),
label: 'archived tasks'
)
],
onTap: (index){
setState(() {
currentIndex = index;
});
},
),
body: screens[currentIndex],
);
}
Future getName() async {
return 'Ahmad Ali';
}
void createDatabase() async {
database = await openDatabase(
'todo.db',
version: 1,
onCreate: (database, version) {
print('databse created');
database.execute(
'CREATE TABLE tasks(id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, date TEXT, time TEXT, status TEXT)'
).then(
(value) {
print('table created');
}
).catchError(
(error){
print('error creating table ${error.toString()}');
}
);
},
onOpen: (databse) async {
print('database opened');
await getData(database).then((value) {
tasks = value;
print(tasks);
});
}
);
}
Future insertIntoDatabase({
required String title,
required String date,
required String time
}
) async {
return await database.transaction(
(txn) {
return txn.rawInsert(
'INSERT INTO tasks (title, date, time, status) VALUES ("$title", "$date", "$timeController", "new")'
).then(
(value) {
print('$value inserted succsessfully');
}
).catchError(
(error){
print('error inserting into table ${error.toString()}');
}
);
}
);
}
Future<List<Map>> getData(Database database) async {
return await database.rawQuery('SELECT * FROM tasks');
}
} ```

Answer 1

Try to initialize
late Database database;
in the StatefulWidget instead of it's State and in the createDatabase() call it like
widget.database = await OpenDatabase...
Also try to see if adding await in initState helps.

Answer 2

instead of
late Database database;
Write
static Database? database;