How to add data to an existing document in firestore - Flutter - flutter

Question

I am using Firebase Database to store information regarding my flutter app.
I have manually updated my collections and documents.
But in one instance I want my users to setdata in my documents so it gets reflected in the app for that particular user. But, when the user does setdate it goes and creates new documents which I do not want, I want the user to setdata in the existing document. I did try but no luck.
Here are my codes:
class FirestoreService {
FirestoreService._();
static final instance = FirestoreService._();
Future<void> setData(
{#required String path, Map<String, dynamic> data}) async {
final reference = Firestore.instance.document(path);
await reference.setData(data);
}
abstract class Database {
Future<void> setRackBook(RackBookItems rackBookItems);
}
bool documentCheckBox() => true;
class FirestoreDatabase implements Database {
final String uid;
FirestoreDatabase({#required this.uid}) : assert(uid != null);
final _service = FirestoreService.instance;
#override
Future<void> setRackBook(RackBookItems rackBookItems) async =>
await _service.setData(
path: APIPath.rackBookItems(uid, rackBookItems.id),
data: rackBookItems.toMap());
}
class PageScreen extends StatefulWidget {
final RackBookItems rackBookItems;
final Database database;
const PageScreen(this.rackBookItems, {#required this.database});
static Future<void> show(
BuildContext context, {
Database database,
RackBookItems rackBookItems,
}) async {
final database = Provider.of<Database>(context);
await Navigator.of(context, rootNavigator: true).push(
MaterialPageRoute(
fullscreenDialog: false,
builder: (context) => PageScreen(
rackBookItems,
database: database,
),
),
);
}
#override
_PageScreenState createState() => _PageScreenState();
}
class _PageScreenState extends State<PageScreen> {
final _formKey = GlobalKey<FormState>();
bool _validateAndSaveForm() {
final form = _formKey.currentState;
if (form.validate()) {
form.save();
return true;
}
return false;
}
Future<void> _completed() async {
if (_validateAndSaveForm()) {
try{
final checkBox = widget.rackBookItems?.checkBox ?? documentCheckBox();
final rackBookItems = RackBookItems(checkBox: checkBox);
await widget.database.setRackBook(rackBookItems);
Navigator.of(context).pop();
} on PlatformException catch (e) {
PlatformExceptionAlertDialog(
title: 'Operations failed',
exception: e,
).show(context);
}
}
}
#override
Widget build(BuildContext context) {
final auth = Provider.of<AuthBase>(context, listen: true);
return SafeArea(
child: Scaffold(
body: Column(
children: <Widget>[
StreamBuilder<User>(
stream: auth.onAuthStateChange,
builder: (context, snapshot) {
User user = snapshot.data;
if (snapshot.hasData) {
return Provider<Database>(
create: (_) => FirestoreDatabase(uid: user.uid),
child: Text('Data'),
);[![enter image description here][1]][1]
}
return Center(
child: CircularProgressIndicator(),
);
},
),
Form(
key: _formKey,
child: RaisedButton(
child: Text(
'Done',
style: TextStyle(color: Theme.of(context).accentColor),
),
onPressed: _completed,
),
)
],
),
),
);
}
}
class RackBookItems {
final String id;
final String rackId;
final String title;
final bool checkBox;
const RackBookItems({
this.id,
this.rackId,
this.title,
this.checkBox,
});
Map<String, dynamic> toMap() {
return {
'checkBox': checkBox,
};
}
factory RackBookItems.fromMap(Map<String, dynamic> data, String id) {
if (data == null) {
return null;
}
final String id = data['id'];
final String rackId = data['rackId'];
final String title = data['title'];
final bool checkBox = data['checkBox'];
return RackBookItems(
id: id,
rackId: rackId,
title: title,
checkBox: checkBox,
);
}
}
This is how my firebase looks like.
[1]: https://i.stack.imgur.com/Z07ai.png
Is there any error with the path I have given?
class APIPath {
static String rackBookItems( String uid, String id) =>
'rackBookItems/$id/';
}

Answer 1

You need to use updateData, this method required you to know the document's Document ID
Firestore.instance.collection('rackBookItems').document('book1').updateData({
'newData' : 14
});
If you need to update all of your documents, you can pull all of the documents and use a for loop to update them.
QuerySnapshot qs = await Firestore.instance.collection('rackBookItems').getDocuments();
List<DocumentSnapshot> books = qs.documents;
for (int i = 0; i < books.length; i++){
Firestore.instance.collection('rackBookItems').documents(books[i].documentID).updateData({
'title' : newData
});
}

Answer 2

updateData is good but in case the document does not exist you should use setData and set merge: true
class FirestoreService {
FirestoreService._();
static final instance = FirestoreService._();
Future<void> setData(
{#required String path, Map<String, dynamic> data}) async {
final reference = Firestore.instance.document(path);
await reference.setData(data, merge:true);
}