I want to check whether the document exist or not without creating the document if it does not exits
Checked() {
Future<DocumentSnapshot> check = linkref.
document(user.UID).
collection("Requests").
document(uuid).get();
return FutureBuilder(
future: check,
builder: (context, ccheck) {
if (check != null ) {
return Text("Available");
}
return Text("not available);
});
}
i tried this code but even if the document does not exists it says that it exists
You should use; if (ccheck.data.exists) instead of if (check != null ). Here is the code;
Checked() {
Future<DocumentSnapshot> check =
linkref.document(user.UID).collection("Requests").document(uuid).get();
return FutureBuilder<DocumentSnapshot>(
future: check,
builder: (context, ccheck) {
if (ccheck.data.exists) {
return Text("Available");
}
return Text("not available");
});
}
You can use the .where( field, isEqualTo: query). This might be useful to you.
final userRef = FirebaseFirestore.instance.collection('users');
checkExists(String query) async {
QuerySnapshot checker = await userRef
.where('uid', isEqualTo: query)
.get();
chkr.docs.forEach((doc) {
if (doc.exists) {
print('Exists');
print(doc.get('uid'));
}else {
print('false');
}
});
}
Then, if you are using a button, you can use onPressed: () => check(yourQuery).
Related
i trying to get a string/check a string for a validation in my flutter app. i've been trying to use the .where() function but they gave me this error when i did it
The argument type 'Future<QuerySnapshot<Object?>>' can't be assigned to the parameter type 'Future<DocumentSnapshot<Object?>>?'
this is the code that give me the error
final phoneNumber = ModalRoute.of(context)!.settings.arguments as String;
CollectionReference users = FirebaseFirestore.instance.collection('users');
return FutureBuilder<DocumentSnapshot>(
future: users.where("phoneNumber", isEqualTo : phoneNumber).get(),
builder:
(BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
if (snapshot.hasError) {
return const Text("Something went wrong");
}
if (snapshot == null || !snapshot.data!.exists) {
return const Text("data doesn't exist");
}
if (snapshot.hasData) {
return const Text("data exist already");
}
if (snapshot.connectionState == ConnectionState.done) {
Map<String, dynamic> data =
snapshot.data!.data() as Map<String, dynamic>;
return Text("Full Name: ${data['full_name']} ${data['last_name']}");
}
return const Text("loading");
},
);
been trying and searching for 3-4 hours but all the reference tell me that i need to input the unique id
that will look like this
final docSnapshot = await Firestore.instance
.collection("$Friseur/1/$Tag/1/$Uhrzeit")
.document(${doc_id_here})
.get();
if(docSnapshot.exists) {
setState(...)
}
else {
setState(...)
}
Change FutureBuilder<DocumentSnapshot> to FutureBuilder<QuerySnapshot>
when you use where operation it return the QuerySnapshot.
Add doc function with document id after where function because future parameter accept Future<DocumentSnapshot<Object?>>?
future: users.where("phoneNumber", isEqualTo : phoneNumber).doc(documentId).get(),
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"
});
I am fairly new to flutter and I hope this problem can be easily solved, but up until now I have no idea what's going wrong.
I have an app where I would like to return a list of users after the search button is pressed. I think that a FutureBuilder with a ListView.builder is the correct choice for this, but somehow I can't get my data to appear in the FutureBuilder even though my async function is definitely finding results.
My future:
Future<List<Map<dynamic, dynamic>>> results;
the button:
onPressed: () {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
setState(() {
results = null;
searched = true;
});
results = getGuestData(widget.place['placeName'], query);
}
},
Async function:
Future<List<Map>> getGuestData(String placeName, Map query) async {
List<Map> result = [];
CollectionReference guestsRef = Firestore.instance
.collection(XXX)
.document(XXX)
.collection(XXX);
if (query['date'] == null) {
guestsRef
.where('lastName', isEqualTo: query['lastName'])
.where('firstName', isEqualTo: query['firstName'])
.getDocuments()
.then((doc) {
if (doc != null) {
result = doc.documents.map((x) => x.data).toList(); \\debugger shows this is working
}
}).catchError((e) => print("error fetching data: $e"));
}
return result;
and finally the problem:
FutureBuilder<List<Map>>(
future: results,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
List guests = snapshot.data;
return ListView.builder(
shrinkWrap: true,
itemCount: guests.length,
itemBuilder: (context, index) {
return ListTile(
... //do stuff here
);
},
);
} else {
return CircularProgressIndicator();
}
},
)
snapshot.data will indeed turn out to be a List, but the size is always 0 despite the getGuestData query finding users.
The idea is to display a string from a random document within a collection in Firebase. A simple function getRandom() retrieves the total number of documents and generates a random integer r that is fed into the Firebase instance.
The output in the app is always null.
StreamBuilder(
initialData: Words(),
stream: getWords(),
builder: (context, snapshot){
if(!snapshot.hasData){
return Center(child: Text("NO DATA"));
}else {
var r = snapshot.data;
return Center(child: Text("${r.english}"));
}
})
Stream<Words> getWords() async* {
int r = await getRandom();
print("RANDOM NO: " + "$r");
Firestore.instance.document("vocabs/foods/words/$r")
.get()
.then((snapshot){
try {
return Words().english;
} catch(e){
print("ERROR");
return null;
}
});
}
class Words{
Words(): super();
String english;
Words.fromSnapshot(DocumentSnapshot snapshot)
: english = snapshot.data["english"];
}
I've constructed a this piece of sample code for you to give you some options to achieve what you'd like to do:
import 'dart:async';
class Word {
final String english;
const Word(this.english);
}
Future<Iterable<Word>> get firebaseSnapshot async => [ Word('aWord'), Word('bWord'), Word('cWord') ];
Stream<String> getEnglishWords() async* {
yield* await firebaseSnapshot.then((words) => Stream.fromIterable(words.map((w) => w.english)));
}
Stream<String> getEnglishWords2() async* {
final words = await firebaseSnapshot.then((words) => words.map((w) => w.english));
yield* Stream.fromIterable(words);
}
Stream<String> getEnglishWords3() async* {
final snapshot = await firebaseSnapshot;
for(final word in snapshot) {
yield word.english;
}
}
main() async {
await for(final englishWord in getEnglishWords()) {
print(englishWord);
}
await for(final englishWord in getEnglishWords2()) {
print(englishWord);
}
await for(final englishWord in getEnglishWords3()) {
print(englishWord);
}
}
Option No. 2 is the one I'd use. There is some significant performance consideration around it. I am scraping the back of my mind for the lecture around it... Nope, can't recall... If I find it, I'll update ya.
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"
});