I have been trying to get a specific field from a specific document. I need token for toWho. But I always got null. How do I fix this?
Main Code is
Future<String> getUserToken(String toWho) async {
DocumentSnapshot _doc = await FirebaseFirestore.instance.doc("tokens/" + toWho).get();
if (_doc != null) {
Map<String, dynamic> _data = _doc.data();
return _data["token"];
} else {
return null;
}
}
in Repository
Future<bool> sendMessage(
MessageModel sendingMessage, UserModel currentUser) async {
if (appMode == AppMode.DEBUG) {
return true;
} else {
var _writePrcs = await _firestoreDBService.saveMessage(sendingMessage);
if (_writePrcs) {
var _token = "";
if (_userToken.containsKey(sendingMessage.toWho)) {
_token = _userToken[sendingMessage.toWho];
print("Token lokalden geldi.");
} else {
_token = await _firestoreDBService.getUserToken(sendingMessage.toWho);
_userToken[sendingMessage.toWho] = _token;
print("Token veritabanından geldi.");
}
Thanks for your help from now on
Try ...........
Future<String> getUserToken(String toWho) async {
DocumentSnapshot _doc = await
FirebaseFirestore.instance.collection("tokens/groupChatId/message").doc(toWho).get();
if (_doc != null) {
Map<String, dynamic> _data = _doc.data();
return _data["token"];
} else {
return null;
}
}
Related
I use flutter to retrieve a document from my firestore database. to do this, I create a DocumentSnapshot type variable which will be passed as a parameter to my getClasseName() function to retrieve the documents. Inside my function the document exists, so I assign it to my variable but my variable remains null when I want to use it
this is a snippet of my code
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:ude/model/enseignant.dart';
class DBServices {
static final CollectionReference lyceecol =
FirebaseFirestore.instance.collection('Lycee');
static Future getUser(String? lycee, String? id) async {
try {
final QuerySnapshot<Object?> snapshot = await lyceecol
.doc(lycee)
.collection('Enseignant')
.where('Id', isEqualTo: id)
.get();
final EnseignantM userData = snapshot.docs
.map((QueryDocumentSnapshot<Object?> e) => EnseignantM.fromSnapshot(
e as DocumentSnapshot<Map<String?, dynamic>>))
.single;
return userData;
} catch (e) {
print('ENSEIGNANT NOT FOUND');
print(e);
throw e;
}
}
static Future getClasseName(
String? lycee, String? id, List<String> list) async {
try {
String classeName;
int i = 0;
final snapshot = await lyceecol
.doc(lycee)
.collection('Enseignant')
.doc(id)
.collection('Classes')
.get();
for (var classe in snapshot.docs) {
DocumentReference<Map<String, dynamic>> classeRef =
classe.data()["reference"];
DocumentSnapshot<Map<String, dynamic>>? classRoom;
await DBServices.getClasse(classeRef.path, classRoom);
if (classRoom != null) {
print('CLASSENAME ${classRoom.data()!["Nom"]}');
classeName = classRoom.data()!["Nom"];
list[i] = classeName;
print(list[i]);
i++;
} else {
print('Impossible de charger les classes affilees a cet enseignant');
}
}
} catch (e) {
print(e);
rethrow;
}
}
static Future<void> getClasse(
String? path, DocumentSnapshot<Map<String, dynamic>>? classroom) async {
try {
await FirebaseFirestore.instance.doc(path!).get().then((snapshot) {
if (snapshot.exists) {
classroom = snapshot; //.data()!["Nom"];
} else {
debugPrint("Document not found");
}
});
debugPrint('CLASSROOMMMM: ${classroom!.data()!["Nom"]}');
} catch (e) {
debugPrint('CLASSE Not EXIST');
print(e);
rethrow;
}
}
}
---
/*this is where the problem is*/
static Future getClasseName(
String? lycee, String? id, List<String> list) async {
try {
String classeName;
int i = 0;
final snapshot = await lyceecol
.doc(lycee)
.collection('Enseignant')
.doc(id)
.collection('Classes')
.get();
for (var classe in snapshot.docs) {
DocumentReference<Map<String, dynamic>> classeRef =
classe.data()["reference"];
DocumentSnapshot<Map<String, dynamic>>? classRoom;
await DBServices.getClasse(classeRef.path, classRoom);
if (classRoom != null) {
print('CLASSENAME ${classRoom.data()!["Nom"]}');
classeName = classRoom.data()!["Nom"];
list[i] = classeName;
print(list[i]);
i++;
} else {
print('Impossible de charger les classes affilees a cet enseignant');
}
}
} catch (e) {
print(e);
rethrow;
}
}
static Future<void> getClasse(
String? path, DocumentSnapshot<Map<String, dynamic>>? classroom) async {
try {
await FirebaseFirestore.instance.doc(path!).get().then((snapshot) {
if (snapshot.exists) {
classroom = snapshot; //.data()!["Nom"];
} else {
debugPrint("Document not found");
}
});
debugPrint('CLASSROOMMMM: ${classroom!.data()!["Nom"]}');
} catch (e) {
debugPrint('CLASSE Not EXIST');
print(e);
rethrow;
}
}
I tried not to pass my variable as a parameter and to directly assign the Document returned by the function to it, but it didn't work.
Your help will be invaluable to me
I have a simple flutter code to retrieve some data from Firestore. the data is retireved correctly, however passing the data from the future function making the result always null. can you advise how to adapt the code to return the list?
that is the class where the actual query is happening:
class DatabaseManager {
final CollectionReference BusinessProfilesCollection =
FirebaseFirestore.instance.collection("BusinessProfilesCollection");
Future GetBusinessProfilesCollection() async {
List businessprofileslist = [];
try {
await BusinessProfilesCollection.get().then((QuerySnapshot) {
QuerySnapshot.docs.forEach((element) {
businessprofileslist.add(element.data());
print(businessprofileslist[0]);
});
});
} catch (e) {
print(e.toString());
return null;
}
}
}
here is the page where I am calling the function: (however the result is always null)
class _ProfilesListPageState extends State<ProfilesListPage> {
List businessprofileslist = [];
#override
void initState() {
super.initState();
fetchBusinessProfilesList();
}
fetchBusinessProfilesList() async {
dynamic result = await DatabaseManager().GetBusinessProfilesCollection();
print(result.toString());
if (result == null) {
print('enable to retieve');
} else {
print('success');
setState(() {
businessprofileslist = result;
});
}
}
#override
Widget build(BuildContext context) {
return Scaffold();
}
}
You're not returning anything from GetBusinessProfilesCollection but null, so the result seems somewhat expected.
I guess you want to do:
class DatabaseManager {
final CollectionReference BusinessProfilesCollection =
FirebaseFirestore.instance.collection("BusinessProfilesCollection");
Future GetBusinessProfilesCollection() async {
List businessprofileslist = [];
try {
var QuerySnapshot = await BusinessProfilesCollection.get();
querySnapshot.docs.forEach((element) {
businessprofileslist.add(element.data());
});
return businessprofileslist;
} catch (e) {
print(e.toString());
return null;
}
}
}
Btw: returning null when the load fails, is just going to lead to a null pointer exception when you then do print(result.toString());. So I recommend not catching the error and just letting it bubble up. With that your code can be simplified to:
class DatabaseManager {
final CollectionReference BusinessProfilesCollection =
FirebaseFirestore.instance.collection("BusinessProfilesCollection");
Future GetBusinessProfilesCollection() async {
var QuerySnapshot = await BusinessProfilesCollection.get();
return querySnapshot.docs.map((element) => element.data());
}
}
You just need to return the list
return businessprofileslist;
CODE :
class DatabaseManager {
final CollectionReference BusinessProfilesCollection =
FirebaseFirestore.instance.collection("BusinessProfilesCollection");
Future GetBusinessProfilesCollection() async {
List businessprofileslist = [];
try {
await BusinessProfilesCollection.get().then((QuerySnapshot) {
QuerySnapshot.docs.forEach((element) {
businessprofileslist.add(element.data());
print(businessprofileslist[0]);
});
// you just need to return the list here after filling it up
return businessprofileslist;
});
} catch (e) {
print(e.toString());
return null;
}
}
}
Code with a little improvement:
class DatabaseManager {
final CollectionReference BusinessProfilesCollection =
FirebaseFirestore.instance.collection("BusinessProfilesCollection");
Future GetBusinessProfilesCollection() async {
await BusinessProfilesCollection.get().then((QuerySnapshot) {
QuerySnapshot.docs.map((doc) => doc.data()).toList();
});
}
}
Try that with calling the function in feching
fetchBusinessProfilesList()
async {
dynamic result ;
await DatabaseManager().GetBusinessProfilesCollection().then((value){
result=value;
print(result.toString());
if (result == null) {
print('enable to retieve');
} else {
print('success');
setState(() {
businessprofileslist = result;
});
}
});
}
I'm trying to upload multiple images in backend.
I got this response when I'm trying to print files:
[Instance of 'MultipartFile', Instance of 'MultipartFile', Instance of 'MultipartFile']
but at a server side I got null array {}. This is my method. I'm using http for api communication.
Future<Map<String, dynamic>> postWithMultiImage(
String _url,
Map<String, String> _headers,
Map<String, String> _params,
String _imageKey,
List _imageFile) async {
if (_headers != null) {
print('_headers => $_headers');
}
print('_params => $_params');
print('_url => $_url');
var request = http.MultipartRequest("POST", Uri.parse(BASE_URL + _url));
if (_headers != null) {
request.headers.addAll(_headers);
}
if (_params != null) {
request.fields.addAll(_params);
}
if (_imageFile != null) {
for (int i = 0; i < _imageFile.length; i++) {
final _type = lookupMimeType(_imageFile[i]);
final _name =
'${DateTime.now().toIso8601String()}.${_type.split('/').last}';
final _partFile = http.MultipartFile(
_imageKey,
File(_imageFile[i]).openRead(),
File(_imageFile[i]).lengthSync(),
filename: _name);
request.files.add(_partFile);
}
print('request files: ${request.files}');
}
var response = await request.send();
final code = response.statusCode;
print('response code => $code');
final responseBody = await http.Response.fromStream(response);
final body = responseBody.body;
final jsonBody = json.decode(body);
Map<String, dynamic> _resDic;
if (code == 200) {
_resDic = Map<String, dynamic>.from(jsonBody);
_resDic[STATUS] = _resDic[SUCCESS] == 1;
} else {
_resDic = Map<String, dynamic>();
_resDic[STATUS] = false;
_resDic[IS_TOKEN_EXPIRED] = 0;
_resDic[MESSAGE] = jsonBody[MESSAGE] != null
? jsonBody[MESSAGE]
: 'Something went wrong';
}
_resDic[HTTP_CODE] = code;
return _resDic;
}
Thanks in advance.
You can try >>THIS<<
Prior to migrating to null safety this worked. This is a user login verification method.
Future<bool> loginValidate() async {
final String dir = await getDocDir(); //getting documents directory
try {
await File('$dir/$_userLoginString.json')
.readAsString()
.then((String contents) {
final json = jsonDecode(contents) as Map<String, dynamic>;
final user = PersonLoginJson.fromJson(json);
if (_userPasswordString != user.password) {
//invalid password
return Future<bool>.value(false);
}
});
} on FileSystemException {
//invalid username
return Future<bool>.value(false);
} catch (e) {
return Future<bool>.value(false);
}
//success
return Future<bool>.value(true);
}
This error occurs when the app is being built.
I believe it has to do with the anonymous function argument within the .then() method.
You need to return the await function and also need to set the true value to make it work:
return await File('$dir/$_userLoginString.json')
.readAsString()
.then((String contents) {
final json = jsonDecode(contents) as Map<String, dynamic>;
final user = PersonLoginJson.fromJson(json);
if (_userPasswordString != user.password) {
//invalid password
return Future<bool>.value(false);
}
//Also need this code as it will return null if not set
return Future<bool>.value(true);
});
BETTER WAY I THINK:
Let's change this code:
await File('$dir/$_userLoginString.json')
.readAsString()
.then((String contents) {
final json = jsonDecode(contents) as Map<String, dynamic>;
final user = PersonLoginJson.fromJson(json);
if (_userPasswordString != user.password) {
//invalid password
return Future<bool>.value(false);
}
});
to this:
String contents = await File('$dir/$_userLoginString.json').readAsString();
final json = jsonDecode(contents) as Map<String, dynamic>;
final user = PersonLoginJson.fromJson(json);
if (_userPasswordString != user.password) {
//invalid password
return Future<bool>.value(false);
}
Then it will be easier to debug your code now.
if (_userPasswordString != user.password) {
//invalid password
return Future<bool>.value(false);
} else {
return Future<bool>.value(true); // <--- here needed
}
i have been trying to get all my data from a sqflite database, when i try to get a single data, this works totally fine:
Future<dynamic> getUser() async {
final db = await database;
var res = await db.query("files");
if (res.length == 0) {
return null;
} else {
var resMap = res[0];
return resMap;
}
}
but when i try to get all data using a for loop like the example below, i get an error
Future<dynamic> getUser() async {
final db = await database;
var res = await db.query("files");
var resMap;
var count = res.length;
if (count != 0) {
for (int i = 0; i < count; i++) {
resMap.add(res[i]);
}
}
return resMap;
}
the error says:
The method 'forEach' was called on null.
Receiver: null
Tried calling: forEach(Closure: (dynamic, dynamic) => Null)
i understand that it says that I've got no data,
and i also tried to remove the if statement, but still no luck!
change this method:
EDIT
Future<List<Map>> getUser() async {
final db = await database;
var res = await db.query("files");
List<Map> resMap = [];
if (res != null res.length > 0) {
for (int i = 0; i < count; i++) {
resMap.add(res[i]);
}
return resMap;
} else
{
return null;
}
}
try this in you widget
List<Map> newUser = [];
#override
void initState() {
super.initState();
getUser();
}
getUser() async {
final _userData = await DBProvider.db.getUser();
if(_userData != null ){
setState(() {
newUser = _userData;
});
} else{
setState(() {
newUser =[];
});
}
}