Develop Reference

The argument type SearchBar can't be assigned to the parameter type Widget in flutter

I'm trying to implement an automatic Search Bar in Flutter.
When compiling I get the error: The argument type 'SearchBar' can't be assigned to the parameter type 'Widget?'.
class Home extends StatelessWidget {
Future<List<Post>> search(String search) async {
await Future.delayed(Duration(seconds: 2));
return List.generate(search.length, (int index) {
return Post(
"Title : $search $index",
"Description :$search $index",
);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 20),
child: SearchBar<Post>(
onSearch: search,
onItemFound: (Post post, int index) {
return ListTile(
title: Text(post.title),
subtitle: Text(post.description),
);
},
),
),
),
);
}
}

From the official Documentation, you need to call the build method to get a widget.
However, it would be better if you create your SearchBar inside your constructor itself, so that a new one doesn't get created every time.
From the official documentation,
class _MyHomePageState extends State<MyHomePage> {
SearchBar searchBar;
AppBar buildAppBar(BuildContext context) {
return new AppBar(
title: new Text('My Home Page'),
actions: [searchBar.getSearchAction(context)]
);
}
_MyHomePageState() {
searchBar = new SearchBar(
inBar: false,
setState: setState,
onSubmitted: print,
buildDefaultAppBar: buildAppBar
);
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: searchBar.build(context)
);
}
}

Flutter Bloc with news api

I am stacked!! and i know i will find help here . I create a flutter application which fetches data from news.org API . Everything was working fine until i started implementing BLOC in the app . I have successfully implemented the first part with BLOC with fetches all the data from the API . the next thing to do is to fetch another data using the categories provided by the API in another page using BLOC .
For instance , there are categories like business , technology , finance etc . So main thing is when the user taps on any of the category the data show be fetched from the API using BLOC .
the following are the codes for the bloc ...
THIS IS THE ERROR I GET
════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
The following assertion was thrown building BlocListener<ArticleBloc, ArticleState>(dirty, state: _BlocListenerBaseState<ArticleBloc, ArticleState>#aae07):
A build function returned null.
The offending widget is: BlocListener<ArticleBloc, ArticleState>
Build functions must never return null.
To return an empty space that causes the building widget to fill available room, return "Container()". To return an empty space that takes as little room as possible, return "Container(width: 0.0, height: 0.0)".
The relevant error-causing widget was:
BlocListener<ArticleBloc, ArticleState> file:///C:/flutter/.pub-cache/hosted/pub.dartlang.org/flutter_bloc-6.1.1/lib/src/bloc_builder.dart:149:12
When the exception was thrown, this was the stack:
#0 debugWidgetBuilderValue. (package:flutter/src/widgets/debug.dart:302:7)
#1 debugWidgetBuilderValue (package:flutter/src/widgets/debug.dart:323:4)
#2 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4632:7)
#3 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4800:11)
#4 Element.rebuild (package:flutter/src/widgets/framework.dart:4343:5)
...
════════════════════════════════════════════════════════════════════════════════════════════════════
RepositoRy
abstract class CategoryRepository {
Future<List<Article>> getCategory(String category);
}
class CatService implements CategoryRepository {
#override
Future<List<Article>> getCategory(String category) async {
// List<Article> categoryNewsList = [];
String url =
"http://newsapi.org/v2/top-headlines?country=us&category=$category&apiKey=df74fc47f0dd401bb5e56c34893a7795";
return getData(url);
/*var response = await http.get(url);
//decode the response into a json object
var jsonData = jsonDecode(response.body);
//check if the status of the response is OK
if (jsonData["status"] == "ok") {
jsonData["articles"].forEach((item) {
//check if the imageUrl and description are not null
if (item["urlToImage"] != null && item["description"] != null) {
//create an object of type NewsArticles
Article newsArticleModel = new Article(
author: item["author"],
title: item["title"],
description: item["description"],
url: item["url"],
urlToImage: item["urlToImage"],
content: item["content"]);
//add data to news list
categoryNewsList.add(newsArticleModel);
}
});
}
return categoryNewsList;*/
}
}
Future<List<Article>> getData(String url) async {
List<Article> items = [];
var response = await http.get(url);
//decode the response into a json object
var jsonData = jsonDecode(response.body);
//check if the status of the response is OK
if (jsonData["status"] == "ok") {
jsonData["articles"].forEach((item) {
//check if the imageUrl and description are not null
if (item["urlToImage"] != null && item["description"] != null) {
//create an object of type NewsArticles
Article article = new Article(
author: item["author"],
title: item["title"],
description: item["description"],
url: item["url"],
urlToImage: item["urlToImage"],
content: item["content"]);
//add data to news list
items.add(article);
}
});
}
return items;
}
Bloc
class ArticleBloc extends Bloc<ArticleEvent, ArticleState> {
CategoryRepository categoryRepository;
ArticleBloc({this.categoryRepository}) : super(ArticleInitial());
#override
Stream<ArticleState> mapEventToState(
ArticleEvent event,
) async* {
if (event is GetArticle) {
try {
yield ArticleLoading();
final articleList =
await categoryRepository.getCategory(event.category);
yield ArticleLoaded(articleList);
} catch (e) {
print(e.message);
}
}
}
}
Event
class GetArticle extends ArticleEvent{
final String category;
GetArticle(this.category);
}
States
#immutable
abstract class ArticleState {
const ArticleState();
}
class ArticleInitial extends ArticleState {
const ArticleInitial();
}
class ArticleLoading extends ArticleState {
const ArticleLoading();
}
class ArticleLoaded extends ArticleState {
final List<Article> articleList;
ArticleLoaded(this.articleList);
}
class ArticleError extends ArticleState {
final String error;
ArticleError(this.error);
#override
bool operator ==(Object object) {
if (identical(this, object)) return true;
return object is ArticleError && object.error == error;
}
#override
int get hashCode => error.hashCode;
}
UI
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'News app',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: BlocProvider(
child: TestCat(),
create: (context) => ArticleBloc(categoryRepository : CatService()),
),
);
}
}
tEST category page
class TestCat extends StatefulWidget {
#override
_TestCatState createState() => _TestCatState();
}
class _TestCatState extends State<TestCat> {
bool isLoading = true;
List<String> categoryItems;
#override
void initState() {
super.initState();
categoryItems = getAllCategories();
// getCategory(categoryItems[0]);
// getCategoryNews();
}
getCategory(cat) async {
context.bloc<ArticleBloc>().add(GetArticle(cat));
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: header(context, isAppTitle: false, title: "App"),
body: _newsBody(context),
);
}
_newsBody(context) {
return ListView(
children: [
//category list
Container(
padding:
EdgeInsets.symmetric(horizontal: NewsAppConstants().margin16),
height: NewsAppConstants().columnHeight70,
child: ListView.builder(
itemCount: categoryItems.length,
itemBuilder: (context, index) {
return TitleCategory(
title: categoryItems[index],
onTap: ()=> callCat(context, categoryItems[index]),
);
},
shrinkWrap: true,
scrollDirection: Axis.horizontal,
),
),
Divider(),
Container(
child: BlocBuilder<ArticleBloc, ArticleState>(
builder: (context, ArticleState articleState) {
//check states and update UI
if (articleState is ArticleInitial) {
return buildInput(context);
} else if (articleState is ArticleLoading) {
return Loading();
} else if (articleState is ArticleLoaded) {
List<Article> articles = articleState.articleList;
updateUI(articles);
} else if (articleState is ArticleError) {
// shows an error widget when something goes wrong
final error = articleState.error;
final errorMsg = "${error.toString()}\nTap to retry";
ShowErrorMessage(
errorMessage: errorMsg,
onTap: getCategory,
);
}
return buildInput(context);
}),
),
],
);
}
getAllCategories() {
List<String> categoryList = [
"Business",
"Entertainment",
"General",
"Sports",
"Technology",
"Health",
"Science"
];
return categoryList;
}
Widget updateUI(List<Article> newsList) {
return SingleChildScrollView(
child: Column(
children: [
Container(
child: ListView.builder(
physics: ClampingScrollPhysics(),
shrinkWrap: true,
itemCount: newsList.length,
itemBuilder: (context, index) {
return NewsBlogTile(
urlToImage: newsList[index].urlToImage,
title: newsList[index].title,
description: newsList[index].description,
url: newsList[index].url,
);
}),
),
Divider(),
],
));
}
buildInput(context) {
ListView.builder(
itemCount: categoryItems.length,
itemBuilder: (context, index) {
return TitleCategory(
title: categoryItems[index],
onTap: () {
print("tapped");
// callCat(context, categoryItems[index]);
},
);
},
shrinkWrap: true,
scrollDirection: Axis.horizontal,
);
}
callCat(BuildContext context, String cat) {
print(cat);
context.bloc<ArticleBloc>().add(GetArticle(cat));
}
}
//this displays the data fetched from the API
class NewsBlogTile extends StatelessWidget {
final urlToImage, title, description, url;
NewsBlogTile(
{#required this.urlToImage,
#required this.title,
#required this.description,
#required this.url});
#override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () {},
child: Expanded(
flex: 1,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Container(
margin: EdgeInsets.all(NewsAppConstants().margin8),
child: Column(
children: <Widget>[
ClipRRect(
borderRadius:
BorderRadius.circular(NewsAppConstants().margin8),
child: Image.network(urlToImage)),
Text(
title,
style: TextStyle(
fontWeight: FontWeight.w600,
color: Colors.black,
fontSize: NewsAppConstants().margin16),
),
SizedBox(
height: NewsAppConstants().margin8,
),
Text(
description,
style: TextStyle(color: Colors.black54),
)
],
),
),
Divider(),
],
),
),
);
}
}
//news title category
class TitleCategory extends StatelessWidget {
final title;
final Function onTap;
TitleCategory({this.title, this.onTap});
#override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () => onTap,
child: Container(
margin: EdgeInsets.all(NewsAppConstants().margin8),
child: Stack(
children: <Widget>[
ClipRRect(
borderRadius: BorderRadius.circular(NewsAppConstants().margin8),
child: Container(
child: Text(
title,
style: TextStyle(
color: Colors.white,
fontSize: NewsAppConstants().font16,
fontWeight: FontWeight.w500),
),
alignment: Alignment.center,
width: NewsAppConstants().imageWidth120,
height: NewsAppConstants().imageHeight60,
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(NewsAppConstants().margin8),
color: Colors.black,
),
),
)
],
),
),
);
}
}

from what I see
you might try one of the below solutions :
try in bloc builder to return Container and inside it handle you states like this :
builder: (context, state) {
return Container(
child: Column(
children: [
if (state is Loading)
CircularProgressIndicator(),
if (state is Loaded)
CatsListView(data: state.data),
try to cover all your kind of states in if/else in your Bloc builder
so let's assume that you have 2 states (state1, state2) so your Bloc builder
would be something like this
builder: (context, state) {
if (state is state1) return Container();
else if (state is state2) return Container();
else return Container();
note that if you covered all states you don't have to do the last else

Load more option in flutter ListView

I want to fetch all the infinite list view data in parts, means Initially it load 10 data item and on scroll more it should fetch next 10 items.
I am fetching data from my Laravel api and in my Laravel api endpoint there is not option for per_page, so Please help me to integrate load more option of list view data.
Here is my List data.
List<Category> _categoryList = List<Category>();
CategoryService _categoryService = CategoryService();
bool isLoading = true;
#override
void initState() {
super.initState();
_getAllCategories();
}
_getAllCategories() async {
var categories = await _categoryService.getCategories();
var result = json.decode(categories.body);
result['data'].forEach((data) {
var model = Category();
model.id = data["id"];
model.name = data["categoryName"];
model.icon = data["categoryIcon"];
setState(() {
_categoryList.add(model);
isLoading = false;
});
});
}
And I am fetching all data in simple ListTile.
child: ListView.builder(
itemCount: //_categoryList.length,
itemBuilder: (context, index) {
return ListTile(
title: _categoryList.name
);
},
),

So I have a trick and I am using it in my project. What we need here is to load more data when we are at the end of the list. So to do that we can use the ListView.builder() only:
child: ListView.builder(
itemCount: _categoryList.length + 1,
itemBuilder: (context, index) {
if(index == _categoryList.length){
// loadMore();
// return Loading();
}
return ListTile(
title: _categoryList.name
);
}),
So what we are doing is that we have set _categoryList.length + 1 to the itemCount. If _categoryList.length was 10 then we will have 11 items in the ListView and the index range will be 0 - 10. So inside the builder, we are checking that the index is equals to _categoryList.length which is 10. If the index is equals to the length of _categoryList.length, then we are at the end of the List and we can simply call some functions to load more data from Api or to show a loading widget.
I guess I got your question right, in this way you can simply lazy load data when user gets to the end of the List without using any third party libraries.

This process called pagination. Laravel provides a function for it check Pagination in Laravel
For example
$users = DB::table('users')->paginate(15);// 15 is limit per page
And check it too Paging lib in flutter dev.

I have created a sample to load more data using web service
You can see this example and you can implement for you json data.
https://android-pratap.blogspot.com/2018/12/flutter-infinite-listview-using.html
import 'package:akeepo/randomuser_infinitelist.dart';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter',
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: InfiniteUsersList(),
);
}
}
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
class InfiniteUsersList extends StatefulWidget {
static String tag = 'users-page';
#override
State<StatefulWidget> createState() {
return new _InfiniteUsersListState();
}
}
class _InfiniteUsersListState extends State<InfiniteUsersList> {
List<User> users = new List<User>();
ScrollController _scrollController = new ScrollController();
bool isPerformingRequest = false;
int pageNumber = 0;
#override
void initState() {
super.initState();
// Loading initial data or first request to get the data
_getMoreData();
// Loading data after scroll reaches end of the list
_scrollController.addListener(() {
if (_scrollController.position.pixels ==
_scrollController.position.maxScrollExtent) {
_getMoreData();
}
});
}
// to show progressbar while loading data in background
Widget _buildProgressIndicator() {
return new Padding(
padding: const EdgeInsets.all(8.0),
child: new Center(
child: new Opacity(
opacity: isPerformingRequest ? 1.0 : 0.0,
child: new CircularProgressIndicator(),
),
),
);
}
#override
void dispose() {
_scrollController.dispose();
super.dispose();
}
// Webservice request to load 20 users data using paging
Future<List<User>> _getUsers() async {
List<User> users = new List<User>();
setState(() {
pageNumber++;
});
String url =
"https://api.randomuser.me/?page=$pageNumber&results=20&seed=abc";
print(url);
var response = await http.get(url);
var jsonData = json.decode(response.body);
print(jsonData);
var usersData = jsonData["results"];
for (var user in usersData) {
User newUser = User(user["name"]["first"] + user["name"]["last"],
user["email"], user["picture"]["large"], user["phone"]);
users.add(newUser);
}
return users;
}
_getMoreData() async {
if (!isPerformingRequest) {
setState(() {
isPerformingRequest = true;
});
List<User> newEntries = await _getUsers(); //returns empty list
if (newEntries.isEmpty) {
double edge = 50.0;
double offsetFromBottom = _scrollController.position.maxScrollExtent -
_scrollController.position.pixels;
if (offsetFromBottom < edge) {
_scrollController.animateTo(
_scrollController.offset - (edge - offsetFromBottom),
duration: new Duration(milliseconds: 500),
curve: Curves.easeOut);
}
}
setState(() {
users.addAll(newEntries);
isPerformingRequest = false;
});
}
}
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Users',
style:
TextStyle(color: Colors.white, fontWeight: FontWeight.bold))),
body: Container(
child: ListView.builder(
shrinkWrap: true,
controller: _scrollController,
itemCount: users.length + 1,
itemBuilder: (BuildContext context, int index) {
if (index == users.length) {
return _buildProgressIndicator();
} else {
return ListTile(
onTap: () {
Navigator.push(
context,
new MaterialPageRoute(
builder: (context) =>
UserDetailPage(users[index])));
},
title: Text(users[index].fullName),
subtitle: Text(users[index].mobileNumber),
leading: CircleAvatar(
backgroundImage: NetworkImage(users[index].imageUrl)),
);
}
})),
);
}
}
class User {
final String fullName;
final String email;
final String imageUrl;
final String mobileNumber;
User(this.fullName, this.email, this.imageUrl, this.mobileNumber);
}
// User Detail Page
class UserDetailPage extends StatelessWidget {
final User user;
UserDetailPage(this.user);
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("User Details"),
),
body: Center(
child: Text(
user.fullName,
style: TextStyle(fontSize: 35.0),
),
),
);
}
}

Information from api doesn't show - Flutter

I have a problem with Future builder in Flutter. It gets the info from api successfully but doesn't show it. When I put print and print the info from api, it is ok and it shows the movies name without any problems. here is my code:
class Search extends StatefulWidget {
final String value;
Search({Key key, String this.value}) : super(key: key);
#override
_SearchState createState() => _SearchState();
}
class _SearchState extends State<Search> {
var title;
Future getSearch({index}) async {
http.Response response = await http.get(
'https://api.themoviedb.org/3/search/company?api_key=6d6f3a650f56fd6b3347428018a20a73&query=' +
widget.value);
var results = json.decode(response.body);
setState(() {
this.title = results['results'];
});
return title[index]['name'];
}
getName(index) {
return title[index]['name'];
}
#override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
backgroundColor: Color(0xff1d1d27),
body: Column(
children: [
Expanded(
child: FutureBuilder(
initialData: [],
future: getSearch(),
builder: (context, snapshot) {
return ListView.builder(itemBuilder: (context, index) {
Padding(
padding:
EdgeInsets.symmetric(horizontal: 30, vertical: 20),
child: Container(
color: Colors.white,
child: Text(getName(index).toString()),
),
);
});
},
))
],
)),
);
}
}

Please Use this code, It works fine to fetch the names and show them on the list,
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
class Search extends StatefulWidget {
final String value;
Search({Key key, String this.value}) : super(key: key);
#override
_SearchState createState() => _SearchState();
}
class _SearchState extends State<Search> {
var title;
var results;
getSearch() async {
http.Response response = await http.get(
'https://api.themoviedb.org/3/search/company?api_key=6d6f3a650f56fd6b3347428018a20a73&query=' +
widget.value);
results = json.decode(
response.body); //make it global variable to fetch it everywhere we need
return results['results'][0]['name'];
}
getName(index) {
return results['results'][index]['name'];
}
#override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
backgroundColor: Color(0xff1d1d27),
body: Column(
children: [
Expanded(
child: FutureBuilder(
// initialData: [],
future: getSearch(),
builder: (context, snapshot) {
String name =
snapshot.data; // to get the data from the getSearch
print(name);
if (snapshot.hasData) {
// if there is data then show the list
return ListView.builder(
itemCount: results['results']
?.length, // to get the list length of results
itemBuilder: (context, index) {
return Padding(
padding: EdgeInsets.symmetric(
horizontal: 30, vertical: 20),
child: Container(
color: Colors.white,
child: Text(getName(index)
.toString()), // pass the index in the getName to get the name
),
);
});
} else {
// if there is no data or data is not loaded then show the text loading...
return new Text("Loading...",
style: TextStyle(fontSize: 42, color: Colors.white));
}
},
))
],
)),
);
}
}
P.S
To Learn the basics of Futurebuilder You can see this article For more learning
I have commented the code to explain more to you.

How to pass the data get from Home widget to it's child widgets in flutter?

I am developing an app for a community with login, signup, meetings and chats in flutter. After login successful, the route goes to Home which has five bottom navigation. I am using Firebase in this app for Authentication and Firestore.
I would like to fetch the data once when Home Component started and pass the data to other five bottom navigation bar components.
Now I am fetching the data whenever I switched between navigation components. This increase the Firestore reads.
I tried passing the data through components using constructor variables. But this doesn't work. It shows error that data can't be passed to bottom navigation components Here is my code.
Home.dart
class Home extends StatefulWidget {
#override
_HomeState createState() => _HomeState();
User currentUser;
String userId;
Home({this.currentUser, this.userId});
}
class _HomeState extends State<Home> {
CurrentUser userInfo;
DocumentSnapshot doc;
int _selectedIndex = 0;
List<String> upcoming_seven_days;
FirestoreService _firestoreService = FirestoreService();
static const TextStyle optionStyle =
TextStyle(fontSize: 30, fontWeight: FontWeight.bold);
static List<Widget> _widgetOptions = <Widget>[
Dashboard(),
MeetingList(),
EventList(),
Chat(),
Profile(),
];
static const List<Widget> _appBarText = <Widget>[
Text(
'Dashboard',
style: TextStyle(
fontWeight: FontWeight.w300,
fontSize: 26,
),
),
Text(
'Meetings',
style: TextStyle(
fontWeight: FontWeight.w300,
fontSize: 26,
),
),
Text(
'Events',
style: TextStyle(fontWeight: FontWeight.w300, fontSize: 26),
),
Text(
'Chat',
style: TextStyle(fontWeight: FontWeight.w300, fontSize: 26),
),
Text(
'Profile',
style: TextStyle(fontWeight: FontWeight.w300, fontSize: 26),
),
];
#override
void initState() {
// TODO: implement initState
super.initState();
//setCurrentUserID(widget.currentUser.uid);
//setCurrentUserData(doc.data());
}
void _onItemTapped(int index) {
setState(() {
_selectedIndex = index;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: _appBarText.elementAt(_selectedIndex)),
body: Container(
padding: EdgeInsets.symmetric(horizontal: 10),
width: double.maxFinite,
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: BottomNavigationBar(
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.dashboard),
title: Text('Dashboard'),
backgroundColor: Colors.black),
BottomNavigationBarItem(
icon: Icon(Icons.people),
title: Text('Meetings'),
backgroundColor: Colors.black),
BottomNavigationBarItem(
icon: Icon(Icons.calendar_view_day),
title: Text('Events'),
backgroundColor: Colors.black),
BottomNavigationBarItem(
icon: Icon(Icons.chat),
title: Text('Chat'),
backgroundColor: Colors.black),
BottomNavigationBarItem(
icon: Icon(Icons.person),
title: Text('Profile'),
backgroundColor: Colors.black),
],
currentIndex: _selectedIndex,
selectedItemColor: Colors.lightBlue[200],
onTap: _onItemTapped,
elevation: 8.0,
backgroundColor: Colors.black,
),
);
}
}
This is where I fetch the data from Firestore whenever the user switch to Meeting list component. I don't want to do like that. Rather, I want to pass the respective data from Home to other components. And it should be snapshot, so it can listen to changes.
MeetingList.dart
class MeetingList extends StatelessWidget {
var userInfo;
FirebaseAuth firebaseAuth = FirebaseAuth.instance;
Future getuserinfo() async {
// final uid = firebaseAuth.currentUser.uid;
// userinfo = await firestoreService.getCurrentUserInfo(uid);
// userinfo = userinfo.data().length;
// //print(userinfo);
// return uid;
final uid = firebaseAuth.currentUser.uid;
DocumentSnapshot user = await FirebaseFirestore.instance
.collection('userProfiles')
.doc(uid)
.get();
userInfo = user.data();
return userInfo;
}
#override
Widget build(BuildContext context) {
CollectionReference meetings =
FirebaseFirestore.instance.collection('meetings');
return FutureBuilder(
future: getuserinfo(),
builder: (context, AsyncSnapshot snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return LoadingIndicator();
} else {
return StreamBuilder<QuerySnapshot>(
stream: meetings.snapshots(),
builder:
(BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) {
return Text('Something went wrong');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return LoadingIndicator();
}
return new ListView(
children: snapshot.data.docs.map((DocumentSnapshot document) {
String meetingRole = document.data()['role'];
var userRole = userInfo['role'];
print(userRole);
if (meetingRole == 'all' || meetingRole == userRole) {
return Meeting_Card(
meeting: document.data(),
);
} else {
return Container();
}
}).toList(),
);
},
);
}
},
);
}
}
Your help would be so much helpful for the community.

You can use Provider package for this, which is a wrapper around the InheritedWidget in flutter.
InheritedWidget is used to efficiently propagate information down
the tree, without having to pass them through various constructors
down the widget tree.
You can find more information about InheritedWidget here.
Provider package is wrapper around InheritedWidget to make them
easier to use and more reusable.
More information on Provider in the documentation here
To implement your solution using Provider:
Create a ChangeNotifier class called UserProvider to hold the data you want common between all the children widgets:
class UserProvider extends ChangeNotifier {
User userInfo;
Future getuserinfo() async {
// final uid = firebaseAuth.currentUser.uid;
// userinfo = await firestoreService.getCurrentUserInfo(uid);
// userinfo = userinfo.data().length;
// //print(userinfo);
// return uid;
final uid = firebaseAuth.currentUser.uid;
DocumentSnapshot user = await FirebaseFirestore.instance
.collection('userProfiles')
.doc(uid)
.get();
userInfo = user.data();
return userInfo;
}
}
Now wrap your Home Widget in a ChangeNotifierProvider widget:
class HomeScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return ChangeNotifierProvider<UserProvider>(
lazy: false,
create: (context) => UserProvider(),
child: Home(),
);
}
}
Now you can access the content of the UserProvider class from wherever down the same widget tree (Any of the tabs) by using:
/// Get an instance of the UserProvider in the ancestors of the current widget tree like this.
UserProvider userProvider = Provider.of<UserProvider>(context);
/// Call any method inside the UserProvider class like this
userProvider.getUserInfo();
/// access any data variables inside the UserProvider class like this.
User userInfo = userProvider.userInfo;
You can also take a look at the Consumer and Selector widgets in the provider package, which provide an efficient ways to redraw the UI based on certain parameters of the ChangeNotifier class, when the notifyListeners() methid is called from the ChangeNotifier class.