Having a little hard time doing what I want to achieve.
I am using googlesheets as database, with autosort function to sort the products.
In flutter, after editing 3 products, the flutter app stops "refreshing" so It stops updating inside the app, but in the googlesheets it's always updating.
This is what I currently have to edit the date.
Future<void> _updateDate(
BuildContext context) async {
final DateTime? nD =
await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(1901, 1),
lastDate: DateTime(2100));
if (nD != oD) {
await widget.provider
.pushNewDate(_nDF, index);
setState(() {});
//this is what I added after changing some code
Future.delayed(const Duration(seconds: 1),
(() => (setState(() {}))));
///
}
}
If you wrap the _updateDate in a set state it will propably work . If it doesnt try _updateDate.then(SetState(){});
after a long time I figured it out it was not on my end bue on google sheets that took a litle time to update. I went for another route!
I have a Future (async) Date&Time picker function which works fine from within the body of my stateful widget which contains the "Builder" and the function can be called via the onpressed by just this:
onPressed: () {SelectDayAndTimeL();},
Code:
Future _selectDayAndTimeL(BuildContext context) async {
DateTime _selectedDay = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2021),
lastDate: DateTime(2030),
builder: (BuildContext context, Widget child) => child);
TimeOfDay _selectedTime = await showTimePicker(
context: context,
initialTime: TimeOfDay.now(),
);
if (_selectedDay != null && _selectedTime != null) {
//a little check
}
setState(() {
selectedDateAndTime = DateTime(
_selectedDay.year,
_selectedDay.month,
_selectedDay.day,
_selectedTime.hour,
_selectedTime.minute,
);
// _selectedDate = _selectedDay;
});
// print('...');
}
Now I want to be able to call this function from different dart files/screens which means I have to keep this function on a different dart file which I have tried to do, but because of the setState in the function it needs to be inside a stateful widget. I have tried putting it inside a stateful widget but keeps getting errors.
class Picker extends StatefulWidget {
#override
_PickerState createState() => _PickerState();
}
class _PickerState extends State<Picker> {
#override
Future<Widget> build(BuildContext context) async { //the error in on the build on this line
DateTime _selectedDay = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2021),
lastDate: DateTime(2030),
builder: (BuildContext context, Widget child) => child);
TimeOfDay _selectedTime = await showTimePicker(
context: context,
initialTime: TimeOfDay.now(),
);
if (_selectedDay != null && _selectedTime != null) {
//a little check
}
setState(() {
selectedDateAndTime = DateTime(
_selectedDay.year,
_selectedDay.month,
_selectedDay.day,
_selectedTime.hour,
_selectedTime.minute,
);
// _selectedDate = _selectedDay;
});
}
}
How do I properly place the Future Function inside a stateful widget and how to call it on an onpressed?
I don't know if the title I gave this question is actually what it's supposed to be, but I don't know how else to put it.
The whole setState inside your method is the problem. Your method should do one thing: get a date and time from the user. And there it's responsibility ends.
Future<DateTime> SelectDayAndTimeL(BuildContext context) async {
DateTime _selectedDay = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2021),
lastDate: DateTime(2030),
builder: (BuildContext context, Widget child) => child);
TimeOfDay _selectedTime = await showTimePicker(
context: context,
initialTime: TimeOfDay.now(),
);
if (_selectedDay != null && _selectedTime != null) {
//a little check
}
return DateTime(
_selectedDay.year,
_selectedDay.month,
_selectedDay.day,
_selectedTime.hour,
_selectedTime.minute,
);
}
Now your onPressed becomes:
onPressed: () async {
final pickedDatetime = await SelectDayAndTimeL(context);
setState(() { selectedDateAndTime = pickedDatetime });
},
You have sucessfully divided your code into the function that picks a thing and your widget, which updates after the thing is picked.
The function that picks the date and time can now be reused in every other widget.
Create a function which will take datetime as a parameter and setstate of the stateful widget. Write this inside the stateful widget. Pass this function to the other class as an argument. Once the date is picked call this method by passing the datetime selected.
You should pass the setState function itself as a parameter to the method. This way, inside the method you will always be using the correct state setter function. That is especially necessary since you need to keep the variables _selectedDay etc inside the widget, not on the static method. Try this:
Future selectDayAndTimeL(BuildContext context, Function(DateTime) dateTimeSetter) async { //add a function to receive and use the
DateTime _selectedDay = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2021),
lastDate: DateTime(2030),
builder: (BuildContext context, Widget child) => child);
TimeOfDay _selectedTime = await showTimePicker(
context: context,
initialTime: TimeOfDay.now(),
);
if (_selectedDay != null && _selectedTime != null) {
//a little check
}
// Create the variable with the picked date
DateTime selectedDateAndTime = DateTime(
_selectedDay.year,
_selectedDay.month,
_selectedDay.day,
_selectedTime.hour,
_selectedTime.minute,
);
//call the function from the parameter, which will be executed on the calling widget
dateTimeSetter(selectedDateAndTime);
....
}
Then, call your function to show the datetime picker passing the context, and a function that receives a DateTime parameter, which will be the parameter picked by the user. When the user picks a date, this function body will be executed, calling setState and setting the pickedTime variable.
class Picker extends StatefulWidget {
DateTime pickedTime;
#override
_PickerState createState() => _PickerState();
}
class _PickerState extends State<Picker> {
#override
Future<Widget> build(BuildContext context) async {
return ...
_selectDayAndTimeL(context, (DateTime time){
setState((){
widget.pickedTime = time;
});
});
...
You can also extract the function from the parameter into a normal named function, and just use its name in the parameter, but I'll leave it as is for now to make it simpler.
Also, don't forget to make your method public and static if necessary for the scope of your code.
I am trying to use the DatePicker in flutter and I want to set the initialDate to DateTime.now() and the lastDate I want to set to DateTime.now() + 20yrs so it increments the year dynamically.
Current I have my lastDate set to the year (2100), but this would cause a problem when the year 2101 reaches. So how can I modify my function to increase the lastDate dynamically?
Here is my function:
DateTime _date = DateTime.now();
Future < Null > _checkInDate(BuildContext contex) async {
DateTime ? _datePicker = await showDatePicker(
context: context,
builder: (BuildContext context, Widget ? child) {
return Theme(
data: ThemeData(
primaryColor: Color(0xFFEF5350),
colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.red)
.copyWith(secondary: Color(0xFFFFF176)),
),
child: child ? ? Text(""),
);
},
initialDate: _date,
firstDate: DateTime.now(),
lastDate: DateTime(2100), //how can i increase the lastDate dynamically?
);
if (_datePicker != null && _datePicker != _date) {
_checkInController.text = DateFormat('dd-MM-yyyy').format(_datePicker);
}
}
Yes you can, use DateTime.now().year to get the current year and then add as many years as you want. Like this:
final date = DateTime(DateTime.now().year + 20);
This question already has answers here:
What does the empty parentheses after the onPressed property mean in Dart?
(5 answers)
Closed 3 years ago.
I'm trying to call the showDatePicker widget once an icon button is clicked, however when i call the onTap method get the following error:
The argument type 'Future' can't be assigned to the parameter type '() → void'.
Please find my code below:
showDatePicker code
DateTime selectedDate = DateTime.now();
Future<Null> _selectDate(BuildContext context) async {
final DateTime picked = await showDatePicker(
context: context,
initialDate: selectedDate,
firstDate: DateTime(2018, 1),
lastDate: DateTime(2101));
if (picked != null && picked != selectedDate)
setState(() {
selectedDate = picked;
});
}
IconButton code
IconButton(
icon: Icon(Icons.date_range),
onPressed: _selectDate(context)),
I'm using the StatefulWidget, please do let me know how to solve this issue. Thanks :)
You are calling _selectDate directly, instead of passing a function that calls _selectDate.
Change your onPressed to onPressed: (){_selectDate(context);}
I've created an InkWell with an onTap function call as such
new InkWell(onTap: _handleSelectedDate,
...
)
Handle _handleSelectedDate is defined as a Future as the following
Future<Null> _handleSelectedDate(BuildContext context, AppModel model) async {
var endYear = new DateTime.now().year + 10;
var startYear = new DateTime.now().year - 100;
DateTime picked = await showDatePicker(
context: context,
initialDate: model.trackDate,
firstDate: new DateTime(startYear, 1),
lastDate: new DateTime(endYear));
if (picked != null) {
if (picked != model.trackDate) {
model.setTrackDate(picked);
}
}
}
If I call _handleSelectedDate with no parameters the call is valid, but I need to be able to pass a BuildContext and my Pages Model data through to it. As soon as I do this I get the following build error.
error: The argument type '(BuildContext, AppModel) → Future<Null>'
can't be assigned to the parameter type '() → void'.
I'm not sure how to resolve this. I just need a way to pass data through to the call so that I can reference my Model data (I'm experimenting with scoped_model)
You can wrap your call in a closure
new InkWell(
onTap: () => _handleSelectedDate(context, myModel),
)
The correct way of calling a Future is
new InkWell(
onTap: () async => await _handleSelectedDate(context, myModel),
)