filledstacks / flutter-tutorials

The repo contains the source code for all the tutorials on the FilledStacks Youtube channel.

Hi there 👋

My name is Dane Mackier. I am the creator of FilledStacks.

• 🔭 Over 2.7 million views
• 🌱 Over 1.1 million blog sessions
• ⭐️ Over 5.6k stars in github

Become a better Flutter engineer every week, in less then 10 minutes

flutter-tutorials's Issues

Your repo can't download

I can't download zip file or clone your repo. It's like corrupt. Can you try to check?

021-completer_dialogs - Error on locator.dart

How can I resolve this error? Thank you!

011-network-sensitive-ui, the StreamProvider already deprecated builder and change it to create.

In Provider 3.2.0, it's already can not be used "builder" in StreamProvider, the error will come out, please change this to create, thanks a lot.

tutorials 010 012 014 view rebuild many times

LoginView push to HomeView, HomeView push to PostView, loginView will rebuild

039 Unhandled Exception: NoSuchMethodError: Class 'NoSuchMethodError' has no instance getter 'message'.

E/flutter (14386): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: NoSuchMethodError: Class 'NoSuchMethodError' has no instance getter 'message'.
E/flutter (14386): Receiver: Instance of 'NoSuchMethodError'
E/flutter (14386): Tried calling: message
E/flutter (14386): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:53:5)
E/flutter (14386): #1 FirestoreService.getUser
package:pasabay_app/services/firestore_service.dart:21
E/flutter (14386):
E/flutter (14386): #2 AuthenticationService._populateCurrentUser
package:pasabay_app/services/authentication_service.dart:74
E/flutter (14386): #3 AuthenticationService.isUserLoggedIn
package:pasabay_app/services/authentication_service.dart:68
E/flutter (14386):
E/flutter (14386): #4 StartUpViewModel.handleStartUpLogic
package:pasabay_app/viewmodels/startup_view_model.dart:14
E/flutter (14386): #5 StartUpView.build.
package:pasabay_app/…/views/startup_view.dart:13
E/flutter (14386): #6 _ViewModelProviderState.initState (package:provider_architecture/viewmodel_provider.dart)

033 Episode_Exception caught by rendering library

══ Exception caught by rendering library ═════════════════════════════════
The following assertion was thrown during layout:
A RenderFlex overflowed by 6.0 pixels on the bottom.

The overflowing RenderFlex has an orientation of Axis.vertical.
The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and black striped pattern. This is usually caused by the contents being too big for the RenderFlex.

errors after updating provider to 3.1.0

Hi,
there is issue on some circumstances:
in your lesson014 every instance of widget has its own widget of ModelView by calling constructor:

class _LoginViewState extends State<LoginView> {
 final TextEditingController _controller = TextEditingController();

 @override
 Widget build(BuildContext context) {
   return BaseWidget<LoginViewModel>(
     // HERE!
     model: LoginViewModel(authenticationService: Provider.of(context)),

But suppose we want to use provider instead of constructor:

class _LoginViewState extends State<LoginView> {
 final TextEditingController _controller = TextEditingController();

 @override
 Widget build(BuildContext context) {
   return BaseWidget<LoginViewModel>(
     // Like that
     model: Provider.of<LoginViewModel>(context),
 
// and of course do something like that:

List<SingleChildCloneableWidget> dependentServices = [
 ProxyProvider<Api, AuthenticationService>(
   builder: (context, api, authenticationService) =>
       AuthenticationService(api: api),
 ),
// HERE
 ChangeNotifierProxyProvider<AuthenticationService, LoginViewModel>(
   initialBuilder: null,
   builder: (context, authenticationService, loginViewModel) =>
       LoginViewModel(authenticationService: authenticationService),
 )
];

and all goes well until :

provider: ^3.0.0 –> provider: 3.1.0

after that we catch errors like that:

I/flutter (15123): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (15123): The following assertion was thrown building BaseWidget<LoginViewModel>(state:
I/flutter (15123): _BaseWidgetState<LoginViewModel>#16c62):
I/flutter (15123): The default constructor of ListenableProvider/ChangeNotifierProvider
I/flutter (15123): must create a new, unused Listenable.
I/flutter (15123): 
I/flutter (15123): If you want to reuse an existing Listenable, use the second constructor:
I/flutter (15123): 
I/flutter (15123): - DO use ChangeNotifierProvider.value to provider an existing ChangeNotifier:
I/flutter (15123): 
I/flutter (15123): MyChangeNotifier variable;
I/flutter (15123): ChangeNotifierProvider.value(
I/flutter (15123):   value: variable,
I/flutter (15123):   child: ...
I/flutter (15123): )
I/flutter (15123): 
I/flutter (15123): - DON'T reuse an existing ChangeNotifier using the default constructor.
I/flutter (15123): 
I/flutter (15123): MyChangeNotifier variable;
I/flutter (15123): ChangeNotifierProvider(
I/flutter (15123):   builder: (_) => variable,
I/flutter (15123):   child: ...
I/flutter (15123): )

I tried to fix it in base_widget.dart in that way:

 @override
 Widget build(BuildContext context) {
//    return ChangeNotifierProvider<T>(
//      builder: (context) => model,
   return ChangeNotifierProvider<T>.value(
     value: model,

is this correct?
Maybe you update samples some way?

045-paginated-realtime-firestore Stream if is empty

hi,

Im trying this code in this page https://www.filledstacks.com/post/how-to-perform-real-time-pagination-with-firestore/

 pagePostsQuery.snapshots().listen((postsSnapshot) {
      if (postsSnapshot.documents.isNotEmpty) {

if empty, the stream connectionState always remains waiting ?
if there is no data how can i solve this ?
Thank you

033_Drawer not showing

ScreenTypeLayout isn't defined for the type 'NavBar'

Hi Dane, many thanks for your great tutorials they have made learning Flutter fun!

I am having an issue following along with your #33 Responsive UI Web App tutorial. Once I attempt to pass the ScreenTypeLayout I am getting a error of "The method 'ScreenTypeLayout' isn't defined for the type 'NavBar'.\nTry correcting the name to the name of an existing method, or defining a method named 'ScreenTypeLayout'. Is there an earlier tutorial referencing the ScreenTypeLayout that I missed prior? Thanks.

022-lifecycle-manager

the repo lib/locator.dart:6:17 went wrong, the wrong message was:

lib/locator.dart:6:17: Error: Method not found: 'GetIt'.
GetIt locator = GetIt();

I dont know how to deal with it.

[AuthenticationService] type 'String' is not a subtype of type 'User'

Future _populateCurrentUser(FirebaseUser user) async {
    //_firebaseAuth.signOut();
    if (user != null) {
      _currentUser = await _firestoreService.getUser(user.uid);
      await _analyticsService.setUserProperties(
        userId: user.uid,
        userRole: _currentUser.userRole,
      );
    }
  }

"_currentUser
Exception has occurred.
_TypeError (type 'String' is not a subtype of type 'User')"

27-location-service main.dart The return type 'Stream<userLocation> is not a StreamController<userLocation> as defined by anonmyous closure

I am getting error at this line

@OverRide
Widget build(BuildContext context) {
return StreamProvider(
builder: (context) => LocationService().locationStream,
child: MaterialApp(title: 'Flutter Demo', home: HomeView()));
}

flutter-tutorials/042-firebase-cloud-storage/lib/models/post.dart

Awesome tutorial tx

Would it be possible to add a example of how to populate a field of type array
i.e. Time [ int hours, int min, int sec ]

Layout Templates for Flutter Web error in NavigationService goBack

Hello. Thanks for your videos.
The function goBack class NavigationService in project Layout Templates for Flutter Web (part 3) I'm getting an error that says:

{
	"resource": ".../flutter-tutorials/037-advanced-web-navigation/00-starting/lib/services/navigation_service.dart",
	"owner": "dart",
	"code": "return_of_invalid_type",
	"severity": 8,
	"message": "A value of type 'void' can't be returned from method 'goBack' because it has a return type of 'bool'.",
	"source": "dart",
	"startLineNumber": 11,
	"startColumn": 12,
	"endLineNumber": 11,
	"endColumn": 43,
	"tags": []
}

Can you please tell me why this is going on? Thank you in advance.

Error in base widget.

The following assertion was thrown building BaseWidget<LoginViewModel>(dirty, state: _BaseWidgetState<ChangeNotifier>#8af6b):
type '(BuildContext, LoginViewModel, Widget) => SingleChildScrollView' is not a subtype of type '(BuildContext, ChangeNotifier, Widget) => Widget'

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

class BaseWidget<T extends ChangeNotifier> extends StatefulWidget {
  final Widget Function(BuildContext context, T model,Widget child) builder;
  final T model;
  final Widget child;
  final Function(T) onModelReady;
  final Function(T) onModelDestroy;
  BaseWidget({Key key, this.builder, this.model, this.child,this.onModelReady,this.onModelDestroy}) : super(key: key);

  @override
  _BaseWidgetState createState() => _BaseWidgetState();

}

class _BaseWidgetState<T extends ChangeNotifier> extends State<BaseWidget<T>> {
  T model;

  @override
  void initState() {
    model = widget.model;
    if(widget.onModelReady!=null){
      widget.onModelReady(model);
    }
    super.initState();
  }

  @override
  void dispose() {
    if(widget.onModelDestroy!=null){
      widget.onModelDestroy(model);
    }
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<T>.value(
      value: model,
      child: Consumer<T>(
        builder: widget.builder,
        child: widget.child,
      ),
    );
  }
}

Login.dart

@override
  Widget build(BuildContext context) {
    return BaseWidget<LoginViewModel>(
      model: LoginViewModel(useCase: Provider.of(context)),
      builder: (context, model, child) {
        return SingleChildScrollView(
          physics: BouncingScrollPhysics(),
          child: Form(
            key: formKey,
            autovalidate: _autoValidate,
            child: Column(
              children: <Widget>[
                _loginTitle(),
                _buildUserName(),
                _buildPassword(),
              ],
            ),
          ),
        );
      },
    );
  }

viewmodels - bloc pattern resemblance.

Hi @FilledStacks ,

I'm wondering if the approach used in the architecture you proposed resembles the bloc pattern.

For example, this code is using the bloc pattern:

class SignInBloc {
  final AuthBase auth;

  SignInBloc({@required this.auth});

  final StreamController<bool> _isLoadingController = StreamController<bool>();

  Stream<bool> get isLoadingStream => _isLoadingController.stream;

  void dispose() {
    _isLoadingController.close();
  }

  void _setIsLoading(bool isLoading) {
    if (!_isLoadingController.isClosed) {
      _isLoadingController.add(isLoading);
    }
  }
} 

And your implementation:

class FeedbackViewModel extends BaseModel {
  FirestoreService _firestoreService = locator<FirestoreService>();
  List<UserFeedback> userFeedback;

  FeedbackViewModel() {
    _firestoreService.feedback.asBroadcastStream().listen(_onFeedbackUpdated);
  }

  void markFeedbackAsRead({@required String feedbackId}) {
    _firestoreService.markFeedbackAsRead(feedbackId: feedbackId);
  }

  void _onFeedbackUpdated(List<UserFeedback> event) {
    userFeedback = event;

    if (userFeedback == null) {
      setState(ViewState.Busy);
    } else {
      setState(userFeedback.length == 0
          ? ViewState.NoDataAvailable
          : ViewState.DataFetched);
    }
  }
}

What do you think?

Tutorial 10, final-no-getit git issue with package

Hello, I'm having this issue. Might be about git ref of provider package.

Git error. Command: git rev-list --max-count=1 proxy-provider
fatal: ambiguous argument 'proxy-provider': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:


'git <command> [<revision>...] -- [<file>...]'

pub get failed (69) -- attempting retry 5 in 16 seconds...

Dispose issue in provider architecture part 2

Hi,

In provider architecture pt2 there is an issue when views and widgets derived from BaseView are disposed.

To reproduce:
Launch the app, login to fetch and show posts on the homeview then go back to login screen.
You will see the FlutterError exception in the debug console content thrown by ChangeNotifier.

I/flutter (30244): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════

I/flutter (30244): The following assertion was thrown while finalizing the widget tree:

I/flutter (30244): A HomeModel was used after being disposed.

I/flutter (30244): Once you have called dispose() on a HomeModel, it can no longer be used.

I/flutter (30244):

I/flutter (30244): When the exception was thrown, this was the stack:

I/flutter (30244): #0      ChangeNotifier._debugAssertNotDisposed.<anonymous closure> 

I/flutter (30244): #1      ChangeNotifier._debugAssertNotDisposed 

I/flutter (30244): #2      ChangeNotifier.dispose 

I/flutter (30244): #3      _BaseViewState.dispose 

I/flutter (30244): #4      StatefulElement.unmount 

I/flutter (30244): #5      _InactiveElements._unmount 

I/flutter (30244): #6      _InactiveElements._unmount.<anonymous closure> 

I/flutter (30244): #7      ComponentElement.visitChildren 

I/flutter (30244): #8      _InactiveElements._unmount 
...

Single model over multiple pages

How to use the same model in multiple pages

I am making a cryptocurrency app and following your provider guide 010 using get it
For the main page, I made a HomeModel class with a list of Coin instances and used it in dashboard page by using BaseView<HomeModel>.
Now, for adding another item to list in HomeModel I move on to another page add_coin where also I use BaseView<HomeModel>.
But here if I register it using locator.registerLazySingleton(()=>HomeModel()); it gives error HomeModel was used after being disposed.
And if I register it using factory it does not change the value in initial page

You can see the code here:
https://github.com/Ayush789/crypto_provider

new provider library version

just update to the lasted Provider version,
We have some issues on MyApp class at userController.
How can I fix that,
Thanks!

"architecutre" instead of "architecture"

Hi! if you ever find some time, you may want to fix the spelling error in project No 10.

architecutre --> architecture

From what I saw, you use it consequently throughout the code (which should make it work - not tested), but since you use the proper spelling the the Readme, it might still cause confusion aat some point and is probably a potential source of error.

validationMessage not implemented in 014

https://github.com/FilledStacks/flutter-tutorials/blob/master/014-provider-v3-updates/2-final/lib/ui/views/login_view.dart

Thank you so much for creating these tutorials, unbelievably helpful! Providers is totally awesome and this example helps me understand it so much!

Would you mind implementing validationMessage in 014? I'm having trouble understanding the logic since BaseWidget gets passed in the child now and it doesn't cause it to render when the message changes.

Also, you're missing a dispose() of the controller in the above file.

I'm having issues with the architecture provider v3 tutorial

Hello, I followed your tutorial, change the deprecated aspects for the correct ones and now I'm having this issue that Idk how to fix:

I/flutter (17376): The following assertion was thrown building BaseWidget<LoginViewModel>(dirty, state:
I/flutter (17376): _BaseWidgetState<ChangeNotifier>#04890):
I/flutter (17376): type '(BuildContext, LoginViewModel, Widget) => Scaffold' is not a subtype of type '(BuildContext,
/flutter (17376): ChangeNotifier, Widget) => Widget'

037 - Advanced URL navigation Navigator issue

Hi, there is no template to report issues so I will jump right to it. With the latest changes and with adding navigatorKey to the MaterialApp, now we cannot easily close scaffold drawer.

Most users want to close the drawer onTap and be redirected. In the latest code if one tries to close the drawer like this:

    return GestureDetector(
      onTap: () {
        // DON'T EVER USE A SERVICE DIRECTLY IN THE UI TO CHANGE ANY KIND OF STATE
        // SERVICES SHOULD ONLY BE USED FROM A VIEWMODEL

        // NEW LINE ADDED TO CLOSE DRAWER
        Navigator.of(context).pop();
        locator<NavigationService>().navigateTo(navigationPath);
      },

it will end up with the following error:

Navigator operation requested with a context that does not include a Navigator.

Can you please direct me to a solution of this issue. There is no exposed DrawerController and I can only open the drawer programatically and I am not aware of other solution to close the drawer besides the above-mentioned one (link below):
https://api.flutter.dev/flutter/material/Drawer-class.html

Items getting disposed when using two or more slivers or listview builders while using Provider

I'm trying to implement two sliver widgets within a custom scroll view, and I'm facing a problem with the state of the data being passed in the Listview Builder which is the same case with the
sliverbuilderlist once I scroll down and come back up the items in the list are disposed and hence I'm getting an error. This is happening only when I use two or more sliver widgets together, the sliver list on its own is fine, right now I'm implementing a collapsable sliverappbar with two tabs, and I'm passing a ListviewBuilder two one of the tabs, and I get an error when I scroll down and up again after a few seconds, please help me understand the problem.

I tried keeping it alive with keepalive mixin but it didn't work

feed[i] paints objects from the Provider Feed

class FeedItemScreen extends StatefulWidget {
  @override
  _FeedItemScreenState createState() => _FeedItemScreenState();
}

class _FeedItemScreenState extends State<FeedItemScreen> with  AutomaticKeepAliveClientMixin<FeedItemScreen>
{
  @override
  Widget build(BuildContext context) {
    final feedData = Provider.of<Feed>(context);
    final feed = feedData.items;

    return ListView.builder(
           itemBuilder: (context, i) => ChangeNotifierProvider(
              builder: (ctx) => feed[i],
              child: FeedsItem(),
            ),
            itemCount: feed.length,
    );
  }

  @override
  bool get wantKeepAlive => true;
}


inside Defaulttabcontroller : I'm passing FeedScreen(), which builds the list to one of the tabs 

  body:  TabBarView(
              children: <Widget>[
                 new NotificationScreen(),
                new FeedScreen(),

I'm using the feed[i] items in another file to access the constructor of the FeedItem and its elements and display the relevant data

/flutter ( 5092): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 5092): The following assertion was thrown building NotificationListener:
I/flutter ( 5092): A FeedItem was used after being disposed.
I/flutter ( 5092): Once you have called dispose() on a FeedItem, it can no longer be used.

FeedItem is the class which my data is passed to, and this is the error I'm getting, I'm getting the same error when using multiple slivers within a single viewport. or multiple scrollable list views bascially

why you use StreamProvider in providerV3 sample code

could you describe me why you use StreamProvider for User
?

List<SingleChildCloneableWidget> uiConsumableProviders = [
  StreamProvider<User>(
    builder: (context) => Provider.of<AuthenticationService>(context, listen: false).user,
  )
];

Question: Business logic of item in viewmodel list

Using your architecture what would you recommend for handling the business logic of an item in the view model's list. For example, using the post view, I would like to add a checkbox that when clicked will change background for this specific post to green. Preferably I'd like to include isChecked bool in the post model rather than creating another viewmodel and using post.id as a reference like the likebutton.

Dispose issue in feedback tutorial

Hi @FilledStacks ,

I would like to thank you for the awesome job you're doing. I love the architecture you proposed.
I'm trying to implement the real stats tutorial using get it and provider.

The issue is that using registerFactory I get the following: "Stream has already been listened too."

I followed your suggestion on the Dispose issue in provider architecture part 2, and I implemented the following code:

StreamSubscription<List<UserFeedback>> subscription;

  FeedbackViewModel() {
    subscription = _firestoreService.feedback.listen(_onFeedbackUpdated);
  }

  @override
  void dispose() {
    subscription.cancel();
    super.dispose();
  }

I'm still having the same issue.

Now, if I implement the following code: locator.registerSingleton(FeedbackViewModel()); ,
remove the dispose method and the subscription variable, I get the following error:

"A FeedbackViewModel was used after being disposed. Once you have called dispose() on a FeedbackViewModel, it can no longer be used."

Did you find a way around this bug?

Regards,

graphql-flutter

hey there. first of all, thank you so much for you effort on bringing flutter architecture to the next level.

I've just followed your tutorial #14 and i am trying to implement graphql-flutter within the proposed architecture. I have a service (ApiGraphqlService) which depends on the AuthenticationService and should be consumed in e.g. PostViewModel.

I've already found a possible solution: zino-hofmann/graphql-flutter#339. But i thought it could be done a more "proper way"?

021 & 037: how to manage the onGenerateRoute

Hi @FilledStacks ,

How to manage the onGenerateRoute to cater for both case 021 & 037?

021 - Completer dialog
037 - Advance url for web

Unhandled Exception: Once you have called dispose() it can no longer be used.

Hi,

Im getting the following error messages after implementing the CRUD code:

[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: A HomeViewModel was used after being disposed.
E/flutter (13683): Once you have called dispose() on a HomeViewModel, it can no longer be used.

Do you have any suggestions on how to solve this?

Thanks!

Issue with Models in provider architecture

HEllo, I've following your awsome tutorials for a while and I've having this issue with de provider architecture:
[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: A SignInModel was used after being disposed. E/flutter (32380): Once you have called dispose() on a SignInModel, it can no longer be used.

Idk if you can help me with that.

Dispose Issue on Tab Container

Demo: https://github.com/VictorUvarov/disposeDemo

• The disposing issue occurs when flipping through the tabs quickly. (May take a couple of pages to occur).

Hi guy, in in example 002-final-no-getit path library was not found

provider:
git:
url: https://github.com/rrousselGit/provider
ref: proxy-provider

012-provider-architecture-pt2 - Number of Like in HomeView does not update automatically

The 012-provider-architecture part 2 final could run smoothly on a real Android device.

When a post is selected and it goes to the PostListItem View then tap the Like button for a few times, the Like does increase in PostListItem View. However, it seems the notifyListeners() method has no effect when I go back to the HomeView using the back button . I need to refresh the page by drag down the scroll list again to reveal the updated Like number.

My flutter SDK version is 1.16.2-pre.41
LG D858HK (android-arm)

This expression has type 'void' and can't be used. return navigatorKey.currentState.pop();

in 034-flutter-web-part3-template-layouts i am getting this error plzz help me how to resolve this.

Request permission to translate your articles to Chinese

Hi Mackier,

I am Elton from Hong Kong. Thanks for sharing the brilliant architecture and design of using provider package. Beforehand, I found there are quite a lot of ways of implementing provider package, but your is the first that implements this in an elegant way, and your posts and YouTube videos explained it well.

As a result, I want to translate your posts into Traditional Chinese and post them onto Medium (and of coz are free for the public) so that more ppl can know about this design.

Thanks,
Elton Lau

Force onModelReady

I am using your BaseModel-BaseWidget arquitecture from 014-provider-v3-updates.
I have the following:

class MyPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    AppModule module = Provider.of<MyModel>(context).appModule;
    return BaseWidget<MyPageViewModel>(
        onModelReady: (model) => model.fetchData(module),
        model: MyPageViewModel(api: Provider.of(context)),
        builder: (context, model, child) => model.busy
            ? Center(
                child: CircularProgressIndicator(),
              )
            : Scaffold(

When the module changes I wanted my data to be fetched again, but I see the BaseWidget is only being rebuilt, without calling the onModelReady. I guess this is because the viewModel has not been disposed, right?

How can I approach these scenario?

Awesome Flutter

This repo is very welcome on https://github.com/Solido/awesome-flutter !

A value of type 'void' can't be returned from method 'pop' because it has a return type of 'bool'.

In tutorial 043-firebase-push-notifications , the pop() method of navigation_service.dart, it throws A value of type 'void' can't be returned from method 'pop' because it has a return type of 'bool'.

It seems that the _navigationKey.currentState.pop() would return void instead of bool

Not relevant

Hi,
From your repo "tutorials / provider_architecture / start":

• In "pubspec.yaml" is written " get_it:" with no version:
  This generates an error in "locator.dart" in the line "GetIt locator = GetIt.instance;"
• Adding the versión "get_it: ^4.0.1" solve this error.

Thank you for your excellent work/tutorial.
J. Pablo.

Provider pattern with exception handling

Hi, first of all, these are really great tutorials. I really love what you have done here.

After viewing most of them I have build my app with provider approach from this article:
https://www.filledstacks.com/post/flutter-architecture-my-provider-implementation-guide/

The way of handling idle and busy is awesome but it looks like it is missing the exception-handling part, sure I can write my own way of exception handling. But Im just wondering if there is an existing sample that has already got a nice approach integrated with your current design? Thanks

Update repo with Provider 4

Hi,

@FilledStacks Thanks for the awesome repo. Any plans for updating the repo with updated provider package?

Is creating HomeViewModel instance like this correct?

flutter-tutorials/031-responsive-architecture-provider/02-final-state-implementation/lib/views/home/home_view.dart

Line 15 in de32c20

viewModel: HomeViewModel(),

Mouse Tracking issue

- i have facing below error. check my code.

═══════════════════════════════════════════════════════
════════ Exception caught by gesture library ═══════════════════════════════════════════════════════
The following JSNoSuchMethodError was thrown while routing a pointer event:
NoSuchMethodError: invalid member on null: 'style'

When the exception was thrown, this was the stack:
package:flutter_demo/extensions/HoverExtensions.dart 12:46
package:flutter/src/rendering/proxy_box.dart 2742:22
package:flutter/src/gestures/mouse_tracking.dart 434:21 _dispatchDeviceCallbacks
package:flutter/src/gestures/mouse_tracking.dart 250:9
package:flutter/src/gestures/mouse_tracking.dart 365:26

════════ (2) Exception caught by scheduler library ═════════════════════════════════════════════════
Assertion failed: org-dartlang-app:///packages/flutter/src/gestures/mouse_tracking.dart:454:12
!_duringDeviceUpdate
is not true
════════════════════════════════════════════════════════════════════════════════════════════════════

════════ (3) Exception caught by gesture library ═══════════════════════════════════════════════════
Assertion failed: org-dartlang-app:///packages/flutter/src/gestures/mouse_tracking.dart:330:12
!_duringDeviceUpdate
is not true
═══════════════════════════════════════════════════════

My Code

HoverExtensions.dart

extension HoverExtensions on Widget {
static final appContainer =
html.window.document.getElementById('app-container');

Widget get showCursorOnHover {
return MouseRegion(
child: this,
onHover: (event) => appContainer.style.cursor = 'pointer',
onExit: (event) => appContainer.style.cursor = 'default',
);
}

Widget get moveUpOnHover {
return TranslateOnHover(
child: this,
);
}
}

TranslateOnHover.dart

class TranslateOnHover extends StatefulWidget {
final Widget child;

const TranslateOnHover({Key key, this.child}) : super(key: key);

@OverRide
_TranslateOnHoverState createState() => _TranslateOnHoverState();
}

class _TranslateOnHoverState extends State {
final nonHoverTransform = Matrix4.identity();
final hoverTransform = Matrix4.identity()..translate(0, -5, 0);

bool _hovering = false;

@OverRide
Widget build(BuildContext context) {
return MouseRegion(
onEnter: (event) => _mouseEnter(true),
onExit: (event) => _mouseEnter(false),
child: AnimatedContainer(
duration: Duration(milliseconds: 200),
child: widget.child,
transform: _hovering ? hoverTransform : nonHoverTransform,
),
);
}

_mouseEnter(bool hovering) {
setState(() {
_hovering = hovering;
});
}
}

Improvement to ServiceNavigation for AppBar back button

In StartupViewModel change:

_navigationService.navigateTo(RoutePaths.Home);
to
_navigationService.replaceTo(RoutePaths.Home);

In NavigationService add:

Future<dynamic> replaceTo(String routeName, {dynamic arguments}) {
    return _navigationKey.currentState
        .pushReplacementNamed(routeName, arguments: arguments);
  }

This will avoid the Back icon on home page resetting the navigation state.

sample infinite list with provider

hi, any sample for infinite list with provider ? i have trying to implement provider with your architecture, but get some trouble with infinite list

034 Flutter Web Template.... pop issue

Anychance someone could look at tis issue...

Dane Mackier

https://stackoverflow.com/questions/60152366/flutter-web-layout-templates-pop-returning-void-but-expects-bool

I am trying to follow along on the 3rd video of the tutorial

change Text string

flutter-tutorials/014-provider-v3-updates/2-final/lib/ui/views/post_view.dart

Line 9 in e3d2345

body: Center(child: Text('Home View')));

Change Text to Text('Post View').