I got FutureBuilder snapshot error when I parsing my JSON i got the:
type 'List' is not a subtype of type 'FutureOr<List>'
is it my Product model error or a parsing error?
my code
late Future<List<Product>> productFuture = getProducts();
static Future<List<Product>> getProducts() async {
var url = '${Constants.API_URL_DOMAIN}action=catalog&category_id=$id';
final response = await http.get(Uri.parse(url));
final body = jsonDecode(response.body);
print(body['data']);
return body['data'].map((e)=>Product.fromJson(e)).toList();
}
FutureBuilder<List<Product>>(
future: productFuture,
builder: (context, snapshot) {
print(snapshot);
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
} else if (snapshot.hasData) {
final catalog = snapshot.data;
return buildCatalog(catalog!);
} else {
print('SNAPSOT DATA ${snapshot.data}');
return Text("No widget to build");
}
}),
Use List.from
return List.from(body['data'].map((e)=>Product.fromJson(e)));
static Future<List<Product>> getProducts() async {
var url = '${Constants.API_URL_DOMAIN}action=catalog&category_id=$id';
final response = await http.get(Uri.parse(url));
final body = jsonDecode(response.body);
print(body['data']);
return List.from(body['data'].map((e)=>Product.fromJson(e)));
}
Try to convert all List<Product> --> List<dynamic>
Related
I am trying to read the data from a list that has the data of Instance of '_JsonQuerySnapshot'.
In the below code I am trying to get the data from DB
getData() async {
var db = FirebaseFirestore.instance;
var categoryList = [];
db.collection('categories')
.doc(value)
.get()
.then((DocumentSnapshot doc) {
var listSubCol = doc["categoryCollection"];
listSubCol.forEach((id) {
db.collection('categories')
.doc(value)
.collection(id)
.get()
.then((snapshot) {
categoryList.add(snapshot);
return categoryList;
});
});
});
}
Below is the code where I am printing the values.
FutureBuilder(
future: getData(),
builder: (BuildContext context, snapshot){
if (snapshot.hasError) {
return Text("Something went wrong");
}
if (snapshot.connectionState == ConnectionState.done) {
print('Data: ${snapshot.data}');
return Text("Text");
}
return Text("Text Outside");
}
)
I got a null value.
Can anyone please help me with how to get the data?
The getData is a Future<void>, so when the FutureBuilder is completed the snapshot.data is always null.
Change getData to return a List of whatever you are getting.
Future<List<Categories>> getData() async {
var db = FirebaseFirestore.instance;
final List<Categories> categoryList = [];
await db.collection('categories')
.doc(value)
.get()
.then((DocumentSnapshot doc) {
var listSubCol = doc["categoryCollection"];
listSubCol.forEach((id) {
db.collection('categories')
.doc(value)
.collection(id)
.get()
.then((snapshot) {
categoryList.add(snapshot);
return categoryList;
});
});
});
return categoryList;
}
getData() async {
var db = FirebaseFirestore.instance;
await db.collection('categories').doc(value).get().then((DocumentSnapshot doc) {
var listSubCol = doc["categoryCollection"];
listSubCol.forEach((id) {
db.collection('categories').doc(value).collection(id).get().then((snapshot) {
snapshot.docs.forEach((element) {
categoryList.add(element.data());
});
});
return categoryList;
});
});
return categoryList;
}
using the above method i got the data from Firestore.
I am trying to get the string value of a future, and saving state in flutter. user chooses the endTime and it should display on the UI untill it ends. however, I am getting the following error:
type 'String' is not a subtype of type 'Future<String>' in type cast
the method:
final Future<SharedPreferences> _prefs =
SharedPreferences.getInstance();
Future<String> _textLine = '' as Future<String>;
Future<String> fastTrue() async {
final SharedPreferences prefs = await _prefs;
String formattedDate = DateFormat('yyyy-MM-dd,
hh:mma').format(endTime);
final textLine = (prefs.getString('formattedDate') ??
Languages.of(context)!.setYourFastTime) as Future<String>;
setState(() {
_textLine = prefs.setString('formattedDate',
Languages.of(context)!.endTimeIs
+'\n$formattedDate').then((bool success) {
return textLine;
});
});
return textLine;
}
in initState():
#override
void initState() {
super.initState();
_textLine = _prefs.then((SharedPreferences prefs) {
return prefs.getString('formattedDate') ??
Languages.of(context)!.setEndTime +'\n'+DateFormat('yyyy-MM-dd,
hh:mma').format(DateTime.now());
});
then in my widget build():
Padding(padding: const EdgeInsets.only(top: 170),
child: FutureBuilder<String>(
future: _textLine,
builder: (BuildContext context,
AsyncSnapshot<String> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return const CircularProgressIndicator();
default:
if (snapshot.hasError) {
return Text('Error: ${snapshot.error}');
} else {
return Text(
Languages.of(context)!.endTimeIs +
"\n${snapshot.data}"
);
}
}
})),
help me, pls, tried using hive, but was not able to get to save the state of the widget. Thanks!
This code throws the error because you try to cast a String to a Future<String>>, although it is a String.
Future<String> _textLine = '' as Future<String>;
If you want to declare a Future with a value, you can use the value method.
Future<String> _textLine = Future.value('');
In a Future Builder im trying to use two methods with different types, both of them fetch data from the api,
the main problem that im having is that both of the function have different types, so im having problem on putting
the two methods because of their types. I tried using
Future.wait(Future[]) aswell but i was getting many errors, there errors where mostly on List,
im still trying to learn how Future Builders work, i worked with FutureBuilders before but didnt have to use two functions inside the FutureBuilder. So if anyone could implement their solution on my code, that would really help and maybe add some comments on why did you make the change so i learn for the future. As a bonus im getting the List is not a subtype of type Map<String, dynamic> error aswell so if anyone could help with that too it would be very helpful. Tried looking into stack over flow answers for that but i couldnt figure it out since i was getting an error on this part
buildSwipeButton() {
return MenuPage(
sendData: fetchLoginData()// i was getting error here,
);
}
buildSwipeButton() {
return MenuPage( // other class name from a different file
sendData: fetchLoginData(),
);
}
buildSwipeButton2() {
return MenuPage( // other class name from a different file
sendData2: fetchWorkingLocationData(),
);
}
Future<LoginData>? fetchLoginData() async {
var url = 'https://dev.api.wurk.skyver.co/api/employees';
String basicAuth = 'Basic ' +
base64Encode(
utf8.encode('${emailController.text}:${passwordController.text}'),
);
var response = await http.get(
Uri.parse(url),
headers: <String, String>{'authorization': basicAuth},
);
print(response.body);
if (response.statusCode == 200) {
print(response.statusCode);
return LoginData.fromJson(
jsonDecode(response.body),
);
} else {
throw Exception('Failed to load LoginData');
}
}
Future<WorkingLocationData>? fetchWorkingLocationData() async {
var url = 'https://dev.api.wurk.skyver.co/api/locations';
String basicAuth = 'Basic ' +
base64Encode(
utf8.encode('${emailController.text}:${passwordController.text}'),
);
var response2 = await http.get(
Uri.parse(url),
headers: <String, String>{'authorization': basicAuth},
);
print(response2.body);
if (response2.statusCode == 200) {
print(response2.statusCode);
return WorkingLocationData.fromJson(
jsonDecode(response2.body),
);
} else {
throw Exception('Failed to load Working Location Data');
}
}
// other file where im trying to use Future Builder
late LoginData data;
Future<LoginData>? sendData;
Future<WorkingLocationData>? sendData2;
body: FutureBuilder<LoginData>(
future: sendData, // trying to use sendData and sendData2
builder: (context, snapshot) {
if (snapshot.hasData) {
LoginData? data1 = snapshot.data;
data = data1!;
print(data.loginPhoneNumber);
return afterLoginBody();
} else if (snapshot.hasError) {
return Text('${snapshot.error}');
}
return Center(child: const CircularProgressIndicator());
},
),
),
Try below code hope its help to you.
late LoginData data;
Future<LoginData>? sendData;
Future<WorkingLocationData>? sendData2;
body: FutureBuilder<LoginData>(
Future.wait([sendData, sendData2]),
builder: (context, AsyncSnapshot<List<dynamic>> snapshot{
snapshot.data[0]; //sendData
snapshot.data[1]; //sendData2
},
),
),
You can try this:
Future? _future;
Future<dynamic> sendData() async {
final data1 = await sendData1();
final data2 = await sendData2();
return [data1, data2];
}
#override
void initState() {
_future = sendData()();
super.initState();
}
///
FutureBuilder(
future: _future,
builder: (context, AsyncSnapshot<dynamic> snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return CupertinoActivityIndicator();
}
if (snapshot.hasError) {
return SomethingWentWrong();
}
final data1= snapshot.data[0] as YourDataModel;
final data2 = snapshot.data[1] as YourDataModel;
});
I am trying to get the updated data from a stream but, even though I get data coming down in my future function, the snapshot.data give me this error:
type '_ControllerStream<dynamic>' is not a subtype of type 'Iterable<dynamic>'
Here is my function and stream:
Future getChat(orderId) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
var _token = prefs.getString('token');
print('The Latest Order Token is $_token');
final Map<String, dynamic> body = {
"id": "$orderId",
};
final List _messageData = [];
var url = Uri.parse('$_server/api/driver/get/convo/?access_token=$_token');
await http.post(url, body: body, headers: {
"Content-Type": 'application/x-www-form-urlencoded'
}).then((http.Response response) {
print(response.body);
switch (response.statusCode) {
case 200:
final Map<String, dynamic> responseData = json.decode(response.body);
print("The ${response.body}");
var x = responseData['message_data'].split(",");
print(x);
for (int i = 0; i < x.length; i++) {
_messageData.add(x[i]);
print(x[i]);
}
print(x);
break;
default:
final Map<String, dynamic> responseData = json.decode(response.body);
print(responseData);
return _messageData;
}
return _messageData;
});
}
Stream getChatData(Duration refreshTime, id) async* {
while (true) {
await Future.delayed(refreshTime);
yield getChat(id).asStream();
}
}
I get this in the data response:
"message_data": ""11-12-21:09:01:14AM - Billy Fakename: fire
test,11-12-21:09:01:30AM - Test TEster: ewserasece,""
My stream builder is:
Stream _chatStream;
#override
void initState() {
_chatStream = getChatData(Duration(seconds: 3), orderid);
super.initState();
}
StreamBuilder(
stream: _chatStream,
builder: (context, snapshot) {
if (snapshot.hasData) {
final messages = snapshot.data;
List<MessageBubble> messageWidgets = [];
for (var message in messages) {
final msgText = message;
final msgSender = message;
// final msgSenderEmail = message.data['senderemail'];
final currentUser = "loggedInUser.displayName";
// print('MSG'+msgSender + ' CURR'+currentUser);
final msgBubble = MessageBubble(
msgText: msgText,
msgSender: msgSender,
user: currentUser == msgSender);
messageWidgets.add(msgBubble);
}
return Expanded(
child: ListView(
reverse: true,
padding:
EdgeInsets.symmetric(vertical: 15, horizontal: 10),
children: messageWidgets,
),
);
} else {
return Center();
}
},
),
But, I get this error: type '_ControllerStream' is not a subtype of type 'Iterable' or the snapshot will be null.
How do I get the information that shows up in the future function, show up in the stream?
Could you show us where you define _chatStream ?
Your StreamBuilder uses _chatStream but you only showed us where you define the method
Future getChat(orderId)
and the method
Stream getChatData(Duration refreshTime, id)
where you create a stream that you do not use in the code you've shared.
Did you want to use getChatData in your StreamBuilder?
Did I miss something?
I want to get List values as ints one by one.
where movieId requires an int value.
help me please
thank you
Future<MovieDetailModel> getMovieDetail(int? movieId) async {
try {
http.Response res = await http
.get(Uri.parse('$mainUrl/movie/$**movieId**?$apiKey&language=ko-KR'))
.timeout(Duration(seconds: 8),
onTimeout: () async => new http.Response('{}', 404));
if (res.statusCode == 404) {
return MovieDetailModel.fromJson({});
}
Map<String, dynamic> result = jsonDecode(res.body);
MovieDetailModel movies = MovieDetailModel.fromJson(result);
return movies;
} catch (e) {
print('MovieDetail $e');
}
return MovieDetailModel.fromJson({});
}
where user.userMovieId value is List .
Widget userMovie(UserModel user) {
return FutureBuilder(
future: this._movieDetailProvider.movies(**user.userMovieId!**),
builder:
(BuildContext context, AsyncSnapshot<MovieDetailModel> snapshot) {
if (snapshot.hasData) {}
Provider.
Future<MovieDetailModel> movies(int movieId) async {
MovieDetailModel movieList = await _movieRepo.getMovieDetail(movieId);
notifyListeners();
return movieList;
}