Cannot retrieve data from nested collection - list

Question

_getDataRowsForCompletedExerciseSets(workoutId) async {
try {
List listOfExercises = await FirebaseFirestore.instance
.collection('users')
.doc(currentUser!.uid)
.collection("workouts")
.doc(workoutId)
.collection("exercises")
.get()
.then((snapShot) => snapShot.docs);
for (int i = 0; i < listOfExercises.length; i++) {
FirebaseFirestore.instance
.collection('users')
.doc(currentUser!.uid)
.collection("workouts")
.doc(workoutId)
.collection("exercises")
.doc(listOfExercises[i].doc.id.toString())
.collection("sets")
.snapshots()
.listen(_createListOfExerciseSets);
}
setState(() {
for (ExerciseSet set in listOfExerciseSets) {
//print(set.weight);
completedExerciseSetRows.add(DataRow(cells: [
DataCell(Text(setCount.toString())),
//const DataCell(VerticalDivider(thickness: 5)),
DataCell(Text(set.weight.toString())),
//const DataCell(VerticalDivider(thickness: 5)),
DataCell(Text(set.reps.toString())),
//const DataCell(VerticalDivider(thickness: 5)),
DataCell((isSetToFailure == true) ? Icon(Icons.check) : Icon(null))
//const DataCell(VerticalDivider(thickness: 5)),
]));
}
});
} on Exception catch (_, e) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(
content: Text(e.toString()),
duration: Duration(milliseconds: 1000),
),
);
}
return Container();
}
_createListOfExerciseSets(QuerySnapshot snapshot) {
var docs = snapshot.docs;
for (var doc in docs) {
listOfExerciseSets.add(ExerciseSet.fromFireStore(doc));
}
print('EXERCISE SETS = ' + listOfExerciseSets.toString());
}
I have the following db structure:
users-->{id}-->workouts-->{id}-->exercises-->{id}-->sets-->{id}--fields
I am trying to get the exercises for a particular workout(id) along with the sets(including fields) for each exercise.
The listOfExercises is always empty (0 items). There are no errors showing either.

Answer 1

Here is what I have right now:
Widget build(BuildContext context) {
var exercisesRef = usersRef
.doc(currentUser!.uid)
.collection('workouts')
.doc(workoutId)
.collection('exercises');
return FutureBuilder<QuerySnapshot>(
future: exercisesRef.get(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.active:
return const Center(
child: kCPI,
);
case ConnectionState.waiting:
return const Center(
child: kCPI,
);
case ConnectionState.none:
return const Center(
child: kCPI,
);
case ConnectionState.done:
if (snapshot.hasError) {
return Text('Error: ${snapshot.error}');
} else if (!snapshot.hasData) {
//print('WORKOUTID = ' + workoutId);
return const Text("Document does not exist");
} else if (snapshot.hasData &&
snapshot.connectionState == ConnectionState.done) {
final exercises = snapshot.data!.docs;
List<Widget> completedExercisesWidgetsList = [];
final _controller = ScrollController();
// for loop - loop through all the exercises for the current workout
for (var doc in exercises) {
bool isRowsGeneratedForPreviousExercises = false;
dataRowsForCompletedExercises = [];
var setList = [];
Map<String, dynamic> exercise;
var exerciseName = '';
exercise = doc.data() as Map<String, dynamic>;
setList = exercise['sets'];
exerciseName = exercise['name'];
//loop through the sets for the exercise
for (var set in setList) {
var setNumber = 0;
var weight = '';
var reps = '';
var isToFailure = false;
setNumber = setList.indexOf(set) + 1;
weight = set['weight'].toString();
reps = set['reps'].toString();
isToFailure = set['isToFailure'];
if (isRowsGeneratedForPreviousExercises == false) {
_generateDataTableRowsForCompletedExercises(
setNumber,
weight,
reps,
isToFailure,
);
}
}
isRowsGeneratedForPreviousExercises = true;
completedExercisesWidgetsList
.add(_completedExercisesDataTableWidget(exerciseName));
} //for loop ends
///Return list of widgets - one widget for each completed exercise for the current workout
return Column(
mainAxisSize: MainAxisSize.max,
children: [
Expanded(
child: ScrollConfiguration(
behavior: ScrollConfiguration.of(context).copyWith(
dragDevices: {
PointerDeviceKind.touch,
PointerDeviceKind.mouse,
},
),
child: ListView(
shrinkWrap: true,
controller: _controller,
physics: const AlwaysScrollableScrollPhysics(),
scrollDirection: Axis.vertical,
children: completedExercisesWidgetsList,
),
),
),
],
);
}
}
return const Text("There was a problem loading content.");
},
);
}
And then simply generating DataTable rows from the data:
void _generateDataTableRowsForCompletedExercises(
setNumber, weight, reps, isToFailure) {
dataRowsForCompletedExercises.add(
DataRow(cells: [
DataCell(Text(setNumber.toString())),
DataCell(Text(weight)),
DataCell(Text(reps)),
DataCell(
(isToFailure == true) ? const Icon(Icons.check) : const Icon(null)),
]),
);
}

Answer 2

I believe your problem is where you use 'then'
Try this code and see the print output
var test = await FirebaseFirestore.instance
.collection('users')
.doc(currentUser!.uid)
.collection("workouts")
.doc(workoutId)
.collection("exercises")
.get()
print(test);