Get all from a Firestore collection in Flutter - firebase

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();
}
);
}
}

Related

How can i get data from firebase by document ID in Flutter? [duplicate]

Edit: This Question is outdated, and I am sure, new documentation and more recent answers are available as of now.
I want to retrieve data of only a single document via its ID. My approach with example data of:
TESTID1 {
'name': 'example',
'data': 'sample data',
}
was something like this:
Firestore.instance.document('TESTID1').get() => then(function(document) {
print(document('name'));
}
but that does not seem to be correct syntax.
I was not able to find any detailed documentation on querying firestore within flutter (dart) since the firebase documentation only addresses Native WEB, iOS, Android etc. but not Flutter. The documentation of cloud_firestore is also way too short. There is only one example that shows how to query multiple documents into a stream which is not what i want to do.
Related issue on missing documentation:
https://github.com/flutter/flutter/issues/14324
It can't be that hard to get data from a single document.
UPDATE:
Firestore.instance.collection('COLLECTION').document('ID')
.get().then((DocumentSnapshot) =>
print(DocumentSnapshot.data['key'].toString());
);
is not executed.
but that does not seem to be correct syntax.
It is not the correct syntax because you are missing a collection() call. You cannot call document() directly on your Firestore.instance. To solve this, you should use something like this:
var document = await Firestore.instance.collection('COLLECTION_NAME').document('TESTID1');
document.get() => then(function(document) {
print(document("name"));
});
Or in more simpler way:
var document = await Firestore.instance.document('COLLECTION_NAME/TESTID1');
document.get() => then(function(document) {
print(document("name"));
});
If you want to get data in realtime, please use the following code:
Widget build(BuildContext context) {
return new StreamBuilder(
stream: Firestore.instance.collection('COLLECTION_NAME').document('TESTID1').snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new Text("Loading");
}
var userDocument = snapshot.data;
return new Text(userDocument["name"]);
}
);
}
It will help you set also the name to a text view.
Null safe code (Recommended)
You can either query the document in a function (for example on press of a button) or inside a widget (like a FutureBuilder).
In a method: (one time listen)
var collection = FirebaseFirestore.instance.collection('users');
var docSnapshot = await collection.doc('doc_id').get();
if (docSnapshot.exists) {
Map<String, dynamic>? data = docSnapshot.data();
var value = data?['some_field']; // <-- The value you want to retrieve.
// Call setState if needed.
}
In a FutureBuilder (one time listen)
FutureBuilder<DocumentSnapshot<Map<String, dynamic>>>(
future: collection.doc('doc_id').get(),
builder: (_, snapshot) {
if (snapshot.hasError) return Text ('Error = ${snapshot.error}');
if (snapshot.hasData) {
var data = snapshot.data!.data();
var value = data!['some_field']; // <-- Your value
return Text('Value = $value');
}
return Center(child: CircularProgressIndicator());
},
)
In a StreamBuilder: (always listening)
StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
stream: collection.doc('doc_id').snapshots(),
builder: (_, snapshot) {
if (snapshot.hasError) return Text('Error = ${snapshot.error}');
if (snapshot.hasData) {
var output = snapshot.data!.data();
var value = output!['some_field']; // <-- Your value
return Text('Value = $value');
}
return Center(child: CircularProgressIndicator());
},
)
If you want to use a where clause
await Firestore.instance.collection('collection_name').where(
FieldPath.documentId,
isEqualTo: "some_id"
).getDocuments().then((event) {
if (event.documents.isNotEmpty) {
Map<String, dynamic> documentData = event.documents.single.data; //if it is a single document
}
}).catchError((e) => print("error fetching data: $e"));
This is simple you can use a DOCUMENT SNAPSHOT
DocumentSnapshot variable = await Firestore.instance.collection('COLLECTION NAME').document('DOCUMENT ID').get();
You can access its data using variable.data['FEILD_NAME']
Update FirebaseFirestore 12/2021
StreamBuilder(
stream: FirebaseFirestore.instance
.collection('YOUR COLLECTION NAME')
.doc(id) //ID OF DOCUMENT
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new CircularProgressIndicator();
}
var document = snapshot.data;
return new Text(document["name"]);
}
);
}
This is what worked for me in 2021
var userPhotos;
Future<void> getPhoto(id) async {
//query the user photo
await FirebaseFirestore.instance.collection("users").doc(id).snapshots().listen((event) {
setState(() {
userPhotos = event.get("photoUrl");
print(userPhotos);
});
});
}
Use this code when you just want to fetch a document from firestore collection , to perform some operations on it, and not to display it using some widget (updated jan 2022 )
fetchDoc() async {
// enter here the path , from where you want to fetch the doc
DocumentSnapshot pathData = await FirebaseFirestore.instance
.collection('ProfileData')
.doc(currentUser.uid)
.get();
if (pathData.exists) {
Map<String, dynamic>? fetchDoc = pathData.data() as Map<String, dynamic>?;
//Now use fetchDoc?['KEY_names'], to access the data from firestore, to perform operations , for eg
controllerName.text = fetchDoc?['userName']
// setState(() {}); // use only if needed
}
}
Simple way :
StreamBuilder(
stream: FirebaseFirestore.instance
.collection('YOUR COLLECTION NAME')
.doc(id) //ID OF DOCUMENT
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new CircularProgressIndicator();
}
var document = snapshot.data;
return new Text(document["name"]);
}
);
}
var document = await FirebaseFirestore.instance.collection('Users').doc('CXvGTxT49NUoKi9gRt96ltvljz42').get();
Map<String,dynamic>? value = document.data();
print(value!['userId']);
You can get the Firestore document by following code:
future FirebaseDocument() async{
var variable = await FirebaseFirestore.instance.collection('Collection_name').doc('Document_Id').get();
print(variable['field_name']);
}
Use this simple code:
Firestore.instance.collection("users").document().setData({
"name":"Majeed Ahmed"
});

Flutter - Receive and then modify data from Stream

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;
});}

Flutter StreamBuilder for multiple firebase documents

I am trying to make my Flutter app update when a change is made to the usersCollection.document(user.uid) firebase document.
When the user document is updated I want to retrieve the data from this document but also from another firebase document, facilitiesCollection.document(...).
My current code
Future<Map> _getCheckedInFacilityData() async {
Map<String, dynamic> result = {};
try {
DocumentSnapshot userDoc =
await _db.usersCollection.document(user.uid).get();
if (userDoc.data['checkedIn']) {
// User is checked in
DocumentSnapshot facDoc = await _db.facilitiesCollection
.document(userDoc.data['activeFacilityID'].toString())
.get();
result['facilityID'] = userDoc.data['activeFacilityID'];
result['sessionID'] = userDoc.data['activeSessionID'];
result['facilityActiveUsers'] = facDoc.data['activeUsers'].length;
result['facilityName'] = facDoc.data['name'];
return result;
}
} catch (er) {
debugPrint(er.toString());
}
return null;
}
FutureBuilder<Map>(
future: _getCheckedInFacilityData(),
builder: (context, map) {
switch (map.connectionState) {
case ConnectionState.waiting:
return Center(child: CircularProgressIndicator());
...
This is currently working but the page is not updated when a change is made to the user document.
I haven't been using Flutter/Dart for long so any ideas are welcome.
Is it possible to return a custom object/map which is comprised of 2 separate documents from a StreamBuilder, or is there another method that will work in my situation.
Surely you can do it with Streams asyncMap() and then listen in StreamBuilder
Basic algoritm
Get stream of you first data type and then asyncMap to wait second data type and return them both
stream.asyncMap(
(v1) async {
final v2 = await Future.delayed(Duration(seconds: 1), () => 4);
return v1 * v2;
},
);
Closer to your code
Stream<Map<String, dynamic>> _getCheckedInFacilityData() {
return _db.usersCollection.document(user.uid).snapshots()
.asyncMap(
(userDoc) async {
final DocumentSnapshot facDoc =
await _db.facilitiesCollection
.document(userDoc.data['activeFacilityID'].toString())
.get();
final Map<String, dynamic> userMap = userDoc.data;
final Map<String, dynamic> facMap = facDoc.data;
return userMap..addAll(facMap);
},
);
}
In this function I merge two maps - be carefull if both maps have identical keys map will keep only last was added key in our case from addAll(facMap)
Last step is to show you streamed data on screen - use StreamBuilder
StreamBuilder<Map>(
stream: _getCheckedInFacilityData(),
builder: (context, snapshot) {
if (snapshot.hasError) {
return Text('${snapshot.error}');
} else if (snapshot.connectionState == ConnectionState.waiting) {
return LinearProgressIndicator();
}
return /* some widget that shows your data*/;
},
),

How to fetch the data from firestore once and reuse it even after navigating to other screen?

I want to fetch data from firestore and use that to build cards in Flutter using ListView on the homepage. While using the navigation menu to switch between screens, I intend to reuse the data once fetched in a session rather than fetching it from the database every time I return to the homepage. But, this is not happening; The data is fetched from the database every time I go to the homepage.
FutureBuilder(
future: databaseService(),
builder: (context, snapshot) {
if (snapshot.hasData) {
stringMap = snapshot.data;
}
return ListView.builder(
itemBuilder: (context, index) {
stringMap.forEach((index, value) => {
print("The stringMap is ${stringMap.keys.toList()}"),
});
return HomepageCards(
user: widget.user,
cardDetails: stringMap[stringMap.keys.toList()[index]],
);
},
itemCount: stringMap.length,
scrollDirection: Axis.vertical,
controller: _controller,
shrinkWrap: true,
);
},
)
databaseService() async {
return DatabaseService().streamHomePage(widget.user);
}
DatabaseService.dart
class DatabaseService {
final Firestore _db = Firestore.instance;
HomePage home = new HomePage();
Map homePageMap = new Map<String, Map<String, dynamic>>();
/// Query a subcollection
Future streamHomePage(FirebaseUser user) async {
// Initialise the model map
home.homeModel = <String, dynamic>{};
home.homeModel['driverDetails'] = new Map();
var ref = _db
.collection('homepage')
.document(user.uid)
.collection('h')
.document('28032020');
// TODO: Try to use cached data. Also try to find the pattern for switching between server and cache
await ref.get(source: Source.serverAndCache).then((ref) => {
ref.data.forEach((index, value) => {
home.homeModel = value,
homePageMap[index] = value,
}),
});
return homePageMap;
}
}
Any leads to make the data once fetched reusable would be highly appreciated.
Since you only want to fetch it once and then fetch it from the session, therefore you can just check if the session contains the data or not. Another way is to use shared_preferences, for example:
SharedPreferences prefs = await SharedPreferences.getInstance();
databaseService() async {
await prefs.setBool('retrieved', true);
return DatabaseService().streamHomePage(widget.user);
}
Then before executing the FutureBuilder check if retrieved is equal to true using getBool() and retrieve data from the session

Query a single document from Firestore in Flutter (cloud_firestore Plugin)

Edit: This Question is outdated, and I am sure, new documentation and more recent answers are available as of now.
I want to retrieve data of only a single document via its ID. My approach with example data of:
TESTID1 {
'name': 'example',
'data': 'sample data',
}
was something like this:
Firestore.instance.document('TESTID1').get() => then(function(document) {
print(document('name'));
}
but that does not seem to be correct syntax.
I was not able to find any detailed documentation on querying firestore within flutter (dart) since the firebase documentation only addresses Native WEB, iOS, Android etc. but not Flutter. The documentation of cloud_firestore is also way too short. There is only one example that shows how to query multiple documents into a stream which is not what i want to do.
Related issue on missing documentation:
https://github.com/flutter/flutter/issues/14324
It can't be that hard to get data from a single document.
UPDATE:
Firestore.instance.collection('COLLECTION').document('ID')
.get().then((DocumentSnapshot) =>
print(DocumentSnapshot.data['key'].toString());
);
is not executed.
but that does not seem to be correct syntax.
It is not the correct syntax because you are missing a collection() call. You cannot call document() directly on your Firestore.instance. To solve this, you should use something like this:
var document = await Firestore.instance.collection('COLLECTION_NAME').document('TESTID1');
document.get() => then(function(document) {
print(document("name"));
});
Or in more simpler way:
var document = await Firestore.instance.document('COLLECTION_NAME/TESTID1');
document.get() => then(function(document) {
print(document("name"));
});
If you want to get data in realtime, please use the following code:
Widget build(BuildContext context) {
return new StreamBuilder(
stream: Firestore.instance.collection('COLLECTION_NAME').document('TESTID1').snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new Text("Loading");
}
var userDocument = snapshot.data;
return new Text(userDocument["name"]);
}
);
}
It will help you set also the name to a text view.
Null safe code (Recommended)
You can either query the document in a function (for example on press of a button) or inside a widget (like a FutureBuilder).
In a method: (one time listen)
var collection = FirebaseFirestore.instance.collection('users');
var docSnapshot = await collection.doc('doc_id').get();
if (docSnapshot.exists) {
Map<String, dynamic>? data = docSnapshot.data();
var value = data?['some_field']; // <-- The value you want to retrieve.
// Call setState if needed.
}
In a FutureBuilder (one time listen)
FutureBuilder<DocumentSnapshot<Map<String, dynamic>>>(
future: collection.doc('doc_id').get(),
builder: (_, snapshot) {
if (snapshot.hasError) return Text ('Error = ${snapshot.error}');
if (snapshot.hasData) {
var data = snapshot.data!.data();
var value = data!['some_field']; // <-- Your value
return Text('Value = $value');
}
return Center(child: CircularProgressIndicator());
},
)
In a StreamBuilder: (always listening)
StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
stream: collection.doc('doc_id').snapshots(),
builder: (_, snapshot) {
if (snapshot.hasError) return Text('Error = ${snapshot.error}');
if (snapshot.hasData) {
var output = snapshot.data!.data();
var value = output!['some_field']; // <-- Your value
return Text('Value = $value');
}
return Center(child: CircularProgressIndicator());
},
)
If you want to use a where clause
await Firestore.instance.collection('collection_name').where(
FieldPath.documentId,
isEqualTo: "some_id"
).getDocuments().then((event) {
if (event.documents.isNotEmpty) {
Map<String, dynamic> documentData = event.documents.single.data; //if it is a single document
}
}).catchError((e) => print("error fetching data: $e"));
This is simple you can use a DOCUMENT SNAPSHOT
DocumentSnapshot variable = await Firestore.instance.collection('COLLECTION NAME').document('DOCUMENT ID').get();
You can access its data using variable.data['FEILD_NAME']
Update FirebaseFirestore 12/2021
StreamBuilder(
stream: FirebaseFirestore.instance
.collection('YOUR COLLECTION NAME')
.doc(id) //ID OF DOCUMENT
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new CircularProgressIndicator();
}
var document = snapshot.data;
return new Text(document["name"]);
}
);
}
This is what worked for me in 2021
var userPhotos;
Future<void> getPhoto(id) async {
//query the user photo
await FirebaseFirestore.instance.collection("users").doc(id).snapshots().listen((event) {
setState(() {
userPhotos = event.get("photoUrl");
print(userPhotos);
});
});
}
Use this code when you just want to fetch a document from firestore collection , to perform some operations on it, and not to display it using some widget (updated jan 2022 )
fetchDoc() async {
// enter here the path , from where you want to fetch the doc
DocumentSnapshot pathData = await FirebaseFirestore.instance
.collection('ProfileData')
.doc(currentUser.uid)
.get();
if (pathData.exists) {
Map<String, dynamic>? fetchDoc = pathData.data() as Map<String, dynamic>?;
//Now use fetchDoc?['KEY_names'], to access the data from firestore, to perform operations , for eg
controllerName.text = fetchDoc?['userName']
// setState(() {}); // use only if needed
}
}
Simple way :
StreamBuilder(
stream: FirebaseFirestore.instance
.collection('YOUR COLLECTION NAME')
.doc(id) //ID OF DOCUMENT
.snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return new CircularProgressIndicator();
}
var document = snapshot.data;
return new Text(document["name"]);
}
);
}
var document = await FirebaseFirestore.instance.collection('Users').doc('CXvGTxT49NUoKi9gRt96ltvljz42').get();
Map<String,dynamic>? value = document.data();
print(value!['userId']);
You can get the Firestore document by following code:
future FirebaseDocument() async{
var variable = await FirebaseFirestore.instance.collection('Collection_name').doc('Document_Id').get();
print(variable['field_name']);
}
Use this simple code:
Firestore.instance.collection("users").document().setData({
"name":"Majeed Ahmed"
});

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