Hello I want to get all docs from a collection in one shot without knowing the docs id's since they are random. Inside each doc I have some data but all I need is the doc itself than I will take the data from each and every one no problem.
I get null every time.
Does anyone know what am I doing wrong?
Thank you in advance.
This is the code :
import 'package:cloud_firestore/cloud_firestore.dart';
Future<Map<String, dynamic>> getVisitedCountries(String ID) async {
Map<String, dynamic> val = <String, dynamic>{};
await FirebaseFirestore.instance
.collection('users')
.doc(ID)
.collection('PersonalData')
.doc(ID)
.collection('Passport')
.doc(ID)
.collection('VisitedCountries')
.doc()
.get()
.then((value) {
if (value.data().isEmpty) {
print("User not found");
} else {
val = value.data();
}
}).catchError((e) {
print(e);
});
return val;
}
This is the structure in the Cloud Firestore
So for everyone who is having this problem, this is the way to solve it.
I solved it thanks to the user : Kantine
Solution : code :
import 'package:cloud_firestore/cloud_firestore.dart';
Future<Iterable> getVisitedCountries(String ID) async {
// Get data from docs and convert map to List
QuerySnapshot querySnapshot = await FirebaseFirestore.instance
.collection('users')
.doc(ID)
.collection('PersonalData')
.doc(ID)
.collection('Passport')
.doc(ID)
.collection('VisitedCountries')
.get();
final val = querySnapshot.docs.map((doc) => doc.data());
return val;
}
I used a query snapshot to get the data and then mapped it.
Related
I am trying to get users name but Flutter gives this error:
The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type.
Try adding either a return or a throw statement at the end.
Method:
String getUserNameFromUID(String uid) {
FirebaseFirestore.instance
.collection('users')
.where('uid', isEqualTo: uid)
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((doc) {
return doc["name"];
});
});
}
How can I solve my problem? if I add return 0 to end of the method it always gives 0.
It always gives 0.(I do not want 0, I want get user name from uid)
String getUserNameFromUID(String uid) {
FirebaseFirestore.instance
.collection('users')
.where('uid', isEqualTo: uid)
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((doc) {
return doc["name"];
});
});
return "0";
}
EDIT: I need a String solution, not Future. The method should return String...
Because my UI is not future builder. Isn't there any way to return one data as String in Firestore database?
First your function should return a Future<String> since it relies on firestore's get wich also returns a future. Also docs is a list, you have to return just one. The first one i guess. In the UI just use a FutureBuilder
Future<String> getUserNameFromUID(String uid) async {
final snapshot = await FirebaseFirestore.instance
.collection('users')
.where('uid', isEqualTo: uid)
.get();
return snapshot.docs.first['name'];
}
Since you can't use FutureBuilder. An ugly alternative is to pass a callback to getUserNameFromUID and call setState from there.
void getUserNameFromUID(String uid, Function (String name) onData) {
final snapshot = await FirebaseFirestore.instance
.collection('users')
.where('uid', isEqualTo: uid)
.get().then((s) => onData(s.docs.first['name']));
}
On your UI
...
getUserNameFromUID(uid, (String name){
setState(()=> name = name);
});
From your last comment just inherit from StatefulWidget. And call the function from inside.
#override
void initState() {
getUserNameFromUID(uid);
}
If you had special requirements about not being able to modify the UI, you should mention that as it conditions the way to use the backend services.
FirebaseFirestore _firestore = FirebaseFirestore.instance;
CollectionReference _userRef = FirebaseFirestore.instance.collection('users');
Future getFriends() async {
List<Map> info = [];
await _firestore
.collection('friends')
.doc('lUb3VEzLQsqxxEhwO3nU')
.collection('friends')
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((element) async {
print("hello " + element.id.toString());
await _userRef.doc(element.id).get().then((value) {
print("lalala" + value.data().toString());
info.add(value.data());
});
});
});
print(info.toString());
}
I am trying to build a Flutter application using Firestore.My firestore has two collections namely users and friends.Collection users contains documents with locations,names and Collection friends contains documents which each have a subcollection friends that store the Unique IDs of "users" who are friends. This is the output when I execute the above function
I/flutter ( 7773): hello eyHBWGrNoxSMe8cQUqWC
I/flutter ( 7773): []
I/flutter ( 7773): lalala{loc: Instance of 'GeoPoint', dname: hamza ansari}
PROBLEM: The data is not getting stored into the list 'info'. Any help with this would be appreciated :D
.Here is a photo of the friends collection.
And here is a photo of the users collection.
Would really love it if someone could help me out here :)
You can access the documents by snapshot.data.documents then you can get document Id like this
var doc= snapshot.data.documents;
var docId=doc[index].documentID
FirebaseFirestore.instance
.collection('dishes')
.doc(docId)
.collection('ingredients')
.snapshots(),
i think the problem is that you are simply not returning anything in your Future.
try this
FirebaseFirestore _firestore = FirebaseFirestore.instance;
CollectionReference _userRef = FirebaseFirestore.instance.collection('users');
Future getFriends() async {
List<Map> info = [];
await _firestore
.collection('friends')
.doc('lUb3VEzLQsqxxEhwO3nU')
.collection('friends')
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((element) async {
print("hello " + element.id.toString());
await _userRef.doc(element.id).get().then((value) {
print("lalala" + value.data().toString());
info.add(value.data());
});
});
});
return info ;
}
The problem seems to be with the conversion of the subcollection to a list. Try the following:
FirebaseFirestore _firestore = FirebaseFirestore.instance;
CollectionReference _userRef = FirebaseFirestore.instance.collection('users');
Future getFriends() async {
List<Map> info = [];
await _firestore
.collection('friends')
.doc('lUb3VEzLQsqxxEhwO3nU')
.collection('friends')
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((element) async {
print("hello " + element.id.toString());
await _userRef.doc(element.id).get().then((value) {
print("lalala" + value.data().toString());
info.add(Map(Map.fromMap(value.data())));
});
});
});
print(info.toString());
}
I am trying to get a document from a Firestore collection using the following code:
firebase_service.dart:
class FirebaseService {
final firestoreInstance = FirebaseFirestore.instance;
final FirebaseAuth auth = FirebaseAuth.instance;
Map<String, dynamic> getProfile(String uid) {
firestoreInstance.collection("Artists").doc(uid).get().then((value) {
return (value.data());
});
}
}
home_view.dart:
Map<String, dynamic> profile =
firebaseService.getProfile(auth.currentUser.uid);
When stepping through the code the profile variable is null in home_view.dart, but value.data() in firebase_service.dart contains a map. Is there a reason why this value isn't being returned in home_view.dart?
Your code needs a few edits, as the getProfile function is async.
class FirebaseService {
final firestoreInstance = FirebaseFirestore.instance;
final FirebaseAuth auth = FirebaseAuth.instance;
// set the return type to Future<Map<String, dynamic>>
Future<Map<String, dynamic>> getProfile(String uid) async { // insert async here
/// insert a return and await here
return await firestoreInstance.collection("Artists").doc(uid).get().then((value) =>
return value.data(); // the brackets here aren't needed, so you can remove them
});
}
}
Then finally in home_view.dart
// insert await here:
Map<String, dynamic> profile = await
firebaseService.getProfile(auth.currentUser.uid);
If you plan to use the getProfile function I suggest you to use a FutureBuilder.
In you home_view.dart's build function write this:
return FutureBuilder(
future: firebaseService.getProfile(auth.currentUser.uid),
builder: (context, snapshot){
if (!snapshot.hasData){
return Center(child: CircularProgressIndicator(),);
}
final Map<String, dynamic> profile = snapshot.data.data();
return YourWidgets();
});
And now you don't need to write:
Map<String, dynamic> profile = await
firebaseService.getProfile(auth.currentUser.uid);
This is an async operation and you have to await for its value.
For reference, you can take a look here at documentation of how propper authentication and CRUD operations made in Firebase with flutter.
I'm attempting to do the following:
Listen to a Firestore stream so when a new document is added, the StreamBuilder will receive it, modify it, and then present it.
The "modification" takes the Stream data, which includes a Firestore UID, gets the data from Firestore with that UID, and then the StreamBuilder is populated with that data.
So the flow is: New document added -> Stream gets document -> Function gets UID from that document -> Function uses that UID to get more data from Firestore -> Function returns to populate StreamBuilder with that new data.
My current set-up is as follows -- which works, but the FutureBuilder is obviously making the Firestore call each time the widget is rebuilt, and nobody wants that.
Stream<QuerySnapshot> upperStream;
void initState() {
super.initState();
upperStream = aStream();
}
Stream<QuerySnapshot> aStream() {
return Firestore.instance
.collection('FirstLevel')
.document(/*ownUID (not related to stream)*/)
.collection('SecondLevel')
.snapshots();
}
Future<List> processStream(List streamData) async {
List futureData = List();
for (var doc in streamData) {
Map<String, dynamic> dataToReturn = Map<String, dynamic>();
DocumentSnapshot userDoc = await Firestore.instance
.collection('FirstLevel')
.document(/*OTHER USER'S UID FROM STREAM*/)
.get();
dataToReturn['i'] = userDoc['i'];
futureData.add(dataToReturn);
}
return futureData;
}
...
...
//The actual widget
Expanded(
child: StreamBuilder(
stream: upperStream,
builder: (context, snapshot) {
// Error/null handling
return FutureBuilder(
future: processStream(snapshot.data.documents),
builder: (context, futureSnap) {
// Error/null handling
return ListView.builder(
shrinkWrap: true,
itemCount: futureSnap.data.length,
scrollDirection: Axis.vertical,
itemBuilder: (context, index) {
//Continuing with populating
});
});
}),
),
What's the best way to handle a flow like this? Creating a method where the data from the Firestore stream is modified and then returned without needing ListView.builder at all?
Edit: I tried creating my own stream like this:
Stream<Map<String, dynamic>> aStream2() async* {
QuerySnapshot snap = await Firestore.instance
.collection(FirstLevel)
.document(/*OWN UID*/)
.collection(SecondLevel)
.getDocuments();
for (var doc in snap.documents) {
Map<String, dynamic> data = Map<String, dynamic>();
DocumentSnapshot userDoc = await Firestore.instance
.collection(FirstLevel)
.document(/*OTHER USER'S UID RECEIVED FROM STREAM*/)
.get();
data['i'] = userDoc['i'];
yield data;
}
}
However, the Stream is not triggered/updated when a new Document is added to the SecondLevel collection.
Alright I think I found the path to the solution. I get the data from the stream, modify it, and then yield it to the StreamBuilder within one method and no longer need the FutureBuilder. The key to this, as Christopher Moore mentioned in the comment, is await for. The stream method looks like this:
Stream<List> aStream() async* {
List dataToReturn = List();
Stream<QuerySnapshot> stream = Firestore.instance
.collection(LevelOne)
.document(OWN UID)
.collection(LevelTwo)
.snapshots();
await for (QuerySnapshot q in stream){
for (var doc in q.documents) {
Map<String, dynamic> dataMap= Map<String, dynamic>();
DocumentSnapshot userDoc = await Firestore.instance
.collection('UserData')
.document(doc['other user data var'])
.get();
dataMap['i'] = userDoc['i'];
//...//
dataToReturn.add(dataMap);
}
yield dataToReturn;
}
}
And then the StreamBuilder is populated with the modified data as I desired.
I found myself using this to implement a chat system using the Dash Chat package in my app. I think using the map function on a stream may be a little cleaner here is a sample:
Stream<List<ChatMessage>> getMessagesForConnection(
String connectionId) {
return _db
.collection('connections')
.doc(connectionId)
.collection('messages')
.snapshots()
.map<List<ChatMessage>>((event) {
List<ChatMessage> messages = [];
for (var doc in event.docs) {
try {
messages.add(ChatMessage.fromJson(doc.data()));
} catch (e, stacktrace) {
// do something with the error
}
}
return messages;
});}
I set up Firestore in my project. I created new collection named categories. In this collection I created three documents with uniq id. Now I want to get this collection in my Flutter application so I created CollectionReference:
Firestore.instance.collection('categories')
but I don't know what next.
I am using this plugin firebase_firestore: 0.0.1+1
This is the easiest way to get all data from collection that I found working, without using deprecated methods.
CollectionReference _collectionRef =
FirebaseFirestore.instance.collection('collection');
Future<void> getData() async {
// Get docs from collection reference
QuerySnapshot querySnapshot = await _collectionRef.get();
// Get data from docs and convert map to List
final allData = querySnapshot.docs.map((doc) => doc.data()).toList();
print(allData);
}
Here is the code if you just want to read it once
QuerySnapshot querySnapshot = await Firestore.instance.collection("collection").getDocuments();
var list = querySnapshot.documents;
Using StreamBuilder
import 'package:flutter/material.dart';
import 'package:firebase_firestore/firebase_firestore.dart';
class ExpenseList extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new StreamBuilder<QuerySnapshot>(
stream: Firestore.instance.collection("expenses").snapshots,
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (!snapshot.hasData) return new Text("There is no expense");
return new ListView(children: getExpenseItems(snapshot));
});
}
getExpenseItems(AsyncSnapshot<QuerySnapshot> snapshot) {
return snapshot.data.documents
.map((doc) => new ListTile(title: new Text(doc["name"]), subtitle: new Text(doc["amount"].toString())))
.toList();
}
}
I was able to figure out a solution:
Future getDocs() async {
QuerySnapshot querySnapshot = await Firestore.instance.collection("collection").getDocuments();
for (int i = 0; i < querySnapshot.documents.length; i++) {
var a = querySnapshot.documents[i];
print(a.documentID);
}
}
Call the getDocs() function, I used build function, and it printed all the document IDs in the console.
As of 2021, there have been some major changes in the cloud_firestore package. I was working with firestore on a project, and found that none of the old tutorials were working due to the API changes.
After going through documentation and a few other answers on Stack, here's the solution for the same.
The first thing that you need to do is create a reference for your collection.
CollectionReference _cat = FirebaseFirestore.instance.collection("categories");
Next step is to query the collection. For this, we will be using the get method on the collection reference object.
QuerySnapshot querySnapshot = await _cat.get()
Finally, we need to parse the query snapshot to read the data from each document within our collection. Here, we will parse each of the documents as maps (dictionaries) and push them to a list.
final _docData = querySnapshot.docs.map((doc) => doc.data()).toList();
The entire function will look something like this:
getDocumentData () async {
CollectionReference _cat = FirebaseFirestore.instance.collection("categories");
final _docData = querySnapshot.docs.map((doc) => doc.data()).toList();
// do any further processing as you want
}
QuerySnapshot snap = await
Firestore.instance.collection('collection').getDocuments();
snap.documents.forEach((document) {
print(document.documentID);
});
Update:
One time read of all data:
var collection = FirebaseFirestore.instance.collection('users');
var querySnapshot = await collection.get();
for (var doc in querySnapshot.docs) {
Map<String, dynamic> data = doc.data();
var fooValue = data['foo']; // <-- Retrieving the value.
}
Listening for all data:
var collection = FirebaseFirestore.instance.collection('users');
collection.snapshots().listen((querySnapshot) {
for (var doc in querySnapshot.docs) {
Map<String, dynamic> data = doc.data();
var fooValue = data['foo']; // <-- Retrieving the value.
}
});
For me it works on cloud_firestore version ^2.1.0
Here is the simple code to display each colection in JSON form. I hope this would help someone
FirebaseFirestore.instance.collection("categories").get().then(
(value) {
value.docs.forEach(
(element) {
print(element.data());
},
);
},
);
the easiest way to retrieve data from the firestore is:
void getData() async {
await for (var messages in _firestore.collection('collection').snapshots())
{
for (var message in messages.docs.toList()) {
print(message.data());
}
}
}
what If you store data in the docs Id ?
if the doc is EMPTY, it would be IMPOSSIBLE to get the id doc, its a bug, unless you set a field in a specific doc
enter image description here
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
final database1 = FirebaseFirestore.instance;
Future<QuerySnapshot> years = database1
.collection('years')
.get();
class ReadDataFromFirestore extends StatelessWidget {
#override
Widget build(BuildContext context) {
return FutureBuilder<QuerySnapshot>(
future: years,
builder: (context, snapshot) {
if (snapshot.hasData) {
final List<DocumentSnapshot> documents = snapshot.data.docs;
return ListView(
children: documents
.map((doc) => Card(
child: ListTile(
title: Text('doc.id: ${doc.id}'),
//subtitle: Text('category: ${doc['category']}'),
),
))
.toList());
} else if (snapshot.hasError) {
return Text(snapshot.error);
}
return CircularProgressIndicator();
}
);
}
}