I have this static function which returns a Future from my database (firebasefirestore). Now I need that to be a double because I have to provide a double to the used Widget. I found FutureBuilder to be a viable Class to use for this kind of scenario, I'm just not sure how to properly implement it in my code. See code below:
class SomellierChart extends StatefulWidget {
SomellierChart(
{Key? key,
required this.color,
required this.textColor,
required this.queryDocumentSnapshot})
: super(key: key);
Color textColor;
Color color;
List<QueryDocumentSnapshot> queryDocumentSnapshot;
@override
_SomellierChartState createState() => _SomellierChartState();
}
class _SomellierChartState extends State<SomellierChart> {
static Future<double> spotData(String day, queryDocumentSnapshot) async {
final documentSnapshot = await FirebaseFirestore.instance
.collection('users')
.doc(FirebaseAuth.instance.currentUser!.uid.toString())
.collection('activity')
.doc('${globals.year}')
.collection('week${globals.week}')
.doc(day.toString())
.get();
if (documentSnapshot.exists) {
print('Document exists');
return documentSnapshot['usage'].toDouble();
} else {
print('Document doesnt exist');
return 0;
}
}
@override
Widget build(BuildContext context) {
return LineChart(
LineChartData(
gridData: FlGridData(
show: false,
),
titlesData: FlTitlesData(
show: true,
rightTitles: SideTitles(showTitles: false),
topTitles: SideTitles(showTitles: false),
leftTitles: SideTitles(showTitles: false),
bottomTitles: SideTitles(
showTitles: true,
reservedSize: 20,
interval: 1,
getTextStyles: (context, value) => GoogleFonts.poppins(
textStyle: TextStyle(
color: Theme.of(context).indicatorColor,
fontWeight: FontWeight.w600,
fontSize: 12,
),
),
getTitles: (value) {
switch (value.toInt()) {
case 0:
return 'Mon';
case 2:
return 'Tue';
case 4:
return 'Wed';
case 6:
return 'Thu';
case 8:
return 'Fri';
case 10:
return 'Sat';
case 12:
return 'Sun';
}
return '';
},
margin: 5,
),
),
borderData: FlBorderData(show: false),
minX: 0,
maxX: 12,
minY: 0,
maxY: 3,
lineBarsData: [
LineChartBarData(
spots: [
FlSpot(0, spotData('1', widget.queryDocumentSnapshot)),
FlSpot(2, spotData('2', widget.queryDocumentSnapshot)),
FlSpot(4, spotData('3', widget.queryDocumentSnapshot)),
FlSpot(6, spotData('4', widget.queryDocumentSnapshot)),
FlSpot(8, spotData('5', widget.queryDocumentSnapshot)),
FlSpot(10, spotData('6', widget.queryDocumentSnapshot)),
FlSpot(12, spotData('7', widget.queryDocumentSnapshot)),
],
isCurved: true,
curveSmoothness: 0.5,
preventCurveOverShooting: true,
colors: [widget.textColor],
barWidth: 3,
isStrokeCapRound: true,
dotData: FlDotData(
show: false,
),
belowBarData: BarAreaData(
show: true,
colors: [
widget.color.withOpacity(0.4),
],
),
),
],
),
);
}
}
The double needs to be provided to the FlSpot. Im doing that using the static function spotData(day, queryDocumentSnapshot) - only problem: I'm returning a Future and not a double...
Thank's a lot for your help!
CodePudding user response:
You can do something like the below:
- Initialize
futureDouble
ininitState()
- Use it inside FutureBuilder
- The value is obtained from
snapshot.data!
(which isdouble
is this case, becauseFutureBuilder<double>
was defined, but you can define it for any object).
class _SomellierChartState extends State<SomellierChart> {
late Future<double> futureDouble;
Future<double> spotData(String day, queryDocumentSnapshot) async {
...
}
@override
void initState() {
super.initState();
futureDouble = spotData('', null);
}
@override
Widget build(BuildContext context) {
return FutureBuilder<double>(
future: futureDouble,
builder: (context, snapshot) {
if (snapshot.hasData) {
return _lineChart(snapshot.data!);
} else if (snapshot.hasError) {
return Text('${snapshot.error}');
}
return const CircularProgressIndicator();
});
}
Widget _lineChart(double value) {
return LineChart(...
);
}
}
You can also have a List of double, e.g.
late Future<List<double>> futureDouble;
Future<List<double>> spotData(String day, queryDocumentSnapshot) async {
...
}
and
return FutureBuilder<List<double>>(...)
in which snapshot.data!
would be List<double>
.
To have a method to return a list of values, you can have something like:
Future<List<double>> values() async {
var list = <double>[];
list.add(await value());
list.add(await value());
list.add(await value());
list.add(await value());
list.add(await value());
list.add(await value());
return list;
}
Future<double> value() async {
return 1;
}