Flutter: How to loop through each field in `DocumentSnapshot.data()` - firebase

Question

I have a collection where each user has their own document. In the document I create a map for a new entry. The document would look something like this:
In my app, I want to get the document and then turn it into a list where each map (titled by the time) would be an entry. I tried looping through it but the problem is that there is not a forEach() in the DocumentSnapshot.data() and it is a type of _JsonDocumentSnapshot.
How can I get this as a List where 2021-05-30 20:49:59.671705, 2021-05-30 20:50:00:600294, ... are individual elements in a list. I plan on building each entry on its own using something such as a ListView.builder() so I would like to have a list of all those entries.
Edit:
My code looks something like this:
journal is just a DocumentReference.
journal.snapshots().forEach((element) {
var data = element.data();
print(element.data());
(data ?? {}).forEach((key, value) {
return JournalEntryData(
date: key,
entryText: value['entryText'],
feeling: value['feeling']);
});
});

Answer 1

The problem was that the type of data which was set to element.data() was Object? hence the forEach() method wasn't defined. I tried casting the element.data() as a List which caused errors so I didn't go further down that path. What I should have done was to cast element.data() as a Map which worked. I also should have used journal.get() and not snapshots() as it is a stream so the await keyword would result in the journal.snapshots().forEach() to never end.
The final code looked something like this:
Future<List<JournalEntryData>> getJournalEntries() async {
List<JournalEntryData> entries = [];
await journal.get().then((document) {
Map data = (document.data() as Map);
data.forEach((key, value) {
print('adding entry');
entries.add(JournalEntryData(
date: key,
entryText: value['entryText'],
feeling: value['feeling'],
));
});
});
return entries;
}
and I would do the following to get the entries:
var entries = await getJournalEntries();

Answer 2

Hey for most of my problems like these I choose to go with this approach;
final result = await _db
.collection("collectionName")
.get();
List<Object> toReturn = [];
for (int i = 0; i < result.docs.length; i++) {
// add data to list you want to return.
toReturn.add();
}
Hopefully, this will be helpful to you.

Answer 3

List collectionElements = [];
void messagesStream() async {
await for (var snapshot in _firestore.collection('your collection').snapshots().where(
(snapshot) => snapshot.docs
.every((element) => element.author == currentUser.id),
)) {
collectionElements.add(snapshot);
}
print(collectionElements);
}
Each element would be added to the collectionElements list.
If you want to access only one field in your snapshot this works fine:
final entryText= element.data()['entryText'];
print(entryText); // this would print "lorem ipsum..."