A guide to Inherited Widgets - Flutter Widgets 101 Ep. 3

What people said

Recommends Celt K. B. · 2019-05 · Stack Overflow · on “How to create a common source of data that all classes and widgets can use in flutter”

My App also works with The Cloud Firestore and I use BLoC to fetch the data from the Firestore. I call my BLoC class in the main when the App starts. If you don't have too many widgets, you can pass the data to your widget. If you have a lot of widget, you could use Inherited widgets to make the data available for all the widgets in your App. Two interesting videos: [LINK] [this video]

Recommends Celt K. B. · 2019-05 · Stack Overflow · on “Is there a way to create a global variable from a firestore Stream<DocumentSnapshot> that updates itself?”

You can use Inherited Widgets. Watch this video: [this video] You can read the data when your App starts using BLoC to separate the data from the UI. It is explained here: [LINK]

Recommends creativecreatorormaybenot · 2019-06 · Stack Overflow · on “How to send data between tabs in Flutter?”

In this case, it is recommended to use InheritedWidget . The documentation for InheritedWidget [LINK] is very comprehensive, including a video from the Flutter team [this video] . First of all, you probably want to create a class that holds the data you want to share. import 'dart:async'; class MyInheritedWidgetData { var sharedData; int someCount; String someMessage; final StreamController _streamController = StreamController.broadcast(); Stream get stream => _streamController.stream; Sink get sink => _streamController.sink; } I just added a bunch of variables to this class. You can populate it with whatever you want. Now, you also want to have an InheritedWidget that holds this data class. clas

Recommends Daniel Eberl · 2019-08 · Stack Overflow · on “How to pass provider with Navigator?”

You would need to make the Provider appear above the Navigator Widget to be an anchestor of the current Widget. That means, it must reside above the MaterialApp() , CupertinoApp() or whatever Directionality() you might use. Please refer to following links for more information about InheritedWidget. [LINK] [this video]

Recommends towhid · 2020-07 · Stack Overflow · on “Best way to pass data from a root to deeper child widget in Flutter”

Inherited widget - If you want to avoid using any third party library.. More can be found here - [LINK] and here [this video] class MyInheritedWidget extends InheritedWidget { final int accountId; final int scopeId; MyInheritedWidget(accountId, scopeId, child): super(child); @override bool updateShouldNotify(MyInheritedWidget old) => accountId != old.accountId || scopeId != old.scopeId; } class MyPage extends StatelessWidget { final int accountId; final int scopeId; MyPage(this.accountId, this.scopeId); Widget build(BuildContext context) { return new MyInheritedWidget( accountId, scopeId, const MyWidget(), ); } } class MyWidget extends StatelessWidget { const MyWidget(); Widget build(BuildContext

Cites Alexander Kwint · 2019-05 · Stack Overflow · on “how can i pass a variable to a class and call that variable in any other screen without it being reset”

I'm not sure put the whole app in a StreamProvider is the best choice. That means the app will be rebuilt on each stream value. To make a Widget available on all screens, you need a TransitionBuilder [LINK] in your MaterialApp . To avoid the external dependency you can also use an InheritedWidget [this video] signed_user.dart import 'package:firebase_auth/firebase_auth.dart'; import 'package:flutter/material.dart'; class SignedUser extends InheritedWidget { final FirebaseUser user; SignedUser({@required this.user, @required Widget child}) : super(child: child); @override bool updateShouldNotify(SignedUser oldWidget) => true; static SignedUser of(BuildContext context) => context.inheritFromWidgetO

Cites Celt K. B. · 2019-06 · Stack Overflow · on “Flutter Search Delegate Architecture (code structure best practices)”

You are welcome. In my case, I use BLoC and I have my read the Data when the App is starting. After the start, I can pass down the data to the other widgets if I need it. It is also possible to use Inherited Widgets to access your data from everywhere in your App ( [this video] or [LINK] )

Cites Eyal Kutz · 2019-08 · Stack Overflow · on “Change Widget on Dropdown onchange event”

use a stateful widget [this video] . you can have a field that says wich widget to show and call set state every time a different option is selected. all three widgets could be added to the main List<Widget> using collection if [LINK] as follows: children: <Widget>[ FormBuilder( key: _fbKey, autovalidate: true, child: Column( children: <Widget>[ FormBuilderDropdown( attribute: "value", decoration: InputDecoration( labelText: "Choose something?"), hint: Text('Select Option'), validators: [FormBuilderValidators.required()], items: user.option.map((v) { return DropdownMenuItem( value: v, child: ListTile( leading: Image.asset( 'assets/img/image.png', width: 50, height: 50, ), title: Text("${v.option}

Cites Charlie Abou Moussa · 2020-06 · Stack Overflow · on “Flutter: JSON data , list under list”

First of all: You can use either moor / moor_flutter moor [LINK] flutter_moor [LINK] OR built_value built_value [LINK] To map the json String and generate fromJson/toJson functions. Example using moor: First, create a moor database (if you have any question I am glad to answer). Second, this would be the class you should use. import 'dart:convert'; import 'package:db/moordb/database.dart'; import 'package:json_annotation/json_annotation.dart' as json; import 'package:moor/moor.dart'; part 'user.g.dart'; @DataClassName("User") class Users extends Table { IntColumn get id => integer().nullable().autoIncrement()(); @JsonKey("index") IntColumn get index => text().nullable()(); @JsonKey("about")

Cites venir · 2022-11 · Stack Overflow · on “Flutter FutureBuilder resolving multiple times without build() being called”

Thank you for the full, reproducible example. print statements inside the builder method of your FutureBuilder are likely misleading you towards the incorrect "culprit". The key "problem" arises from this line: FocusScopeNode currentFocus = FocusScope.of(context); In case you didn't know, Flutter's .of static methods expose InheritedWidget [LINK] APIs of some kind. By convention, in a .of method you can usually find a call to dependOnInheritedWidgetOfExactType , which is meant to register the caller, i.e. the children Widget , as a dependency , i.e. a Widget that depends and react to changes of a InheritedWidget of that type. Shortly, putting a .of inside a build method is meant to trigger r