Flutter bloc_pattern returning NoSuchMethodError - flutter

Question

I am building my first Flutter app, and foolishly enough, I started off with complex structures such as the MVVM, I don't know very much about it but have tried.
Here is my folder structure:
lib
---models
------videos.dart
---repos
------videos.dart
---viewmodels
------videos.dart
main.dart (I know)
In my main.dart file, I am using StreamBuilder to fetch the lisit of videos, here's the code:
class Home extends StatelessWidget {
VideosBloc videosBloc = BlocProvider.getBloc<VideosBloc>();
#override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
Expanded(
flex: 1,
child: CustomAppBar(),
),
Expanded(
flex: 9,
child: Container(
color: Theme.of(context).primaryColorDark,
child: StreamBuilder(
stream: videosBloc.videosStream,
builder: (context, snapshot) {
List<Video> videos = snapshot != null ? snapshot.data : [];
return ListView(
children: videos.map((video) {
return VideoContainer(video);
}).toList(),
);
},
),
),
)
],
);
}
}
There there is this bloc file:
import 'dart:async';
import 'package:bloc_pattern/bloc_pattern.dart';
import 'package:peeke_vines/models/videos.dart';
import 'package:peeke_vines/repositories/videos.dart';
import 'package:rxdart/rxdart.dart';
class VideosBloc extends BlocBase {
VideosBloc();
//Stream that receives a number and changes the count;
var _videosController =
BehaviorSubject<List<Video>>.seeded(VideosRepo().getVideos());
//output
Stream<List<Video>> get videosStream => _videosController.stream;
//input
Sink<List<Video>> get videosSink => _videosController.sink;
//dispose will be called automatically by closing its streams
#override
void dispose() {
_videosController.close();
super.dispose();
}
}
And this bloc gets this data from a repository
import 'package:peeke_vines/models/videos.dart';
class VideosRepo {
VideosRepo();
List<Video> videos = VideoModel().fetchVideos();
List<Video> getVideos() {
return [];
}
}
And this repository currently just gets the data from a model, but later I'll implement a web service to fetch the data from:
import 'package:meta/meta.dart';
class VideoModel {
List<Video> fetchVideos() {
return [
Video(
video: 'assets/videos/main.wmv',
title: 'Peeke Vines Video Title',
date: '2 Days ago',
thumbnail: 'assets/thumbnails/1.jpg',
duration: 13.5),
Video(
video: 'assets/videos/main.wmv',
title: 'Peeke Vines Video Title',
date: '2 Days ago',
thumbnail: 'assets/thumbnails/2.jpg',
duration: 13.5),
Video(
video: 'assets/videos/main.wmv',
title: 'Peeke Vines Video Title',
date: '2 Days ago',
thumbnail: 'assets/thumbnails/1.jpg',
duration: 13.5)
];
}
}
class Video {
String video, title, date, thumbnail;
double duration;
Video(
{#required this.video,
#required this.title,
#required this.date,
#required this.thumbnail,
#required this.duration});
}
Now, whenever I import the bloc in the main.dart file using this line:
VideosBloc videosBloc = BlocProvider.getBloc<VideosBloc>();
I get this error:
I/flutter ( 4338): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 4338): The following NoSuchMethodError was thrown building MyApp(dirty):
I/flutter ( 4338): Class 'NoSuchMethodError' has no instance getter 'message'.
I/flutter ( 4338): Receiver: Instance of 'NoSuchMethodError'
I/flutter ( 4338): Tried calling: message
I/flutter ( 4338):
I/flutter ( 4338): When the exception was thrown, this was the stack:
I/flutter ( 4338): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:50:5)
I/flutter ( 4338): #1 BlocProvider.getBloc (package:bloc_pattern/src/bloc_provider.dart:47:12)
I/flutter ( 4338): #2 new Home (package:peeke_vines/main.dart:35:40)
I/flutter ( 4338): #3 MyApp.build (package:peeke_vines/main.dart:21:20)
I/flutter ( 4338): #4 StatelessElement.build (package:flutter/src/widgets/framework.dart:3974:28)
I/flutter ( 4338): #5 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3924:15)
I/flutter ( 4338): #6 Element.rebuild (package:flutter/src/widgets/framework.dart:3721:5)
I/flutter ( 4338): #7 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3907:5)
I/flutter ( 4338): #8 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3902:5)
I/flutter ( 4338): #9 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3084:14)
I/flutter ( 4338): #10 Element.updateChild (package:flutter/src/widgets/framework.dart:2887:12)
I/flutter ( 4338): #11 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:939:16)
I/flutter ( 4338): #12 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:910:5)
I/flutter ( 4338): #13 RenderObjectToWidgetAdapter.attachToRenderTree.<anonymous closure> (package:flutter/src/widgets/binding.dart:856:17)
I/flutter ( 4338): #14 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2320:19)
I/flutter ( 4338): #15 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:855:13)
Can you tell me why this error is coming?

Answer 1

The issue is that you are trying to get the Bloc outside of the build method.
Try to get it at the start of the build method.