In the realm of Flutter development, efficient state management is crucial for building robust and maintainable applications. With the growing complexity of User interfaces and user interactions, developers seek reliable patterns to manage states effectively. One such pattern that has gained significant traction in the Flutter community is the Flutter Bloc pattern.
In this blog post, we’ll delve into the Flutter Bloc pattern, exploring its core concepts, benefits, and implementation with practical examples.
The Flutter Bloc pattern is a state management solution that separates the presentation layer from the business logic. It helps in organizing code and making it easier to maintain and test. In essence, it involves the following components:
Related read: State Management Using Flutter BloC
When you use Flutter bloc you are going to create events to trigger the interactions with the app and then the bloc in charge is going to emit the requested data with a state, in a real example it will be like this:
🔸 The user clicks on a button to get a list of games.
🔸 The event is triggered and it informs the bloc that the user wants a list of games.
🔸 The bloc is going to request this data ( from a repository for example, which is in charge of connecting to the API to get the data).
🔸 When the bloc has the data it will determine if the data is a Success or Error, and then it’s going to emit a state.
🔸 The view is going to be listening to all the possible states that the Flutter Bloc pattern could emit to reach them. For instance, if bloc emits Success as a state the view is going to rebuild it with a list of games, but if the state is Error the view is going to rebuild with an error message or whatever you want to show.
Let’s walk through a simple example to understand how to implement the Bloc pattern in Flutter. Suppose we have a counter application where users can increment and decrement a counter value.
Example code:
abstract class CounterEvent {}
class IncrementEvent extends CounterEvent {}
class DecrementEvent extends CounterEvent {}Example code:
import 'dart:async';
class CounterBloc {
int _counter = 0;
final _counterStateController = StreamController<int>();
StreamSink<int> get _inCounter => _counterStateController.sink;
Stream<int> get counter => _counterStateController.stream;
final _counterEventController = StreamController<CounterEvent>();
Sink<CounterEvent> get counterEventSink => _counterEventController.sink;
CounterBloc() {
_counterEventController.stream.listen(_mapEventToState);
}
void _mapEventToState(CounterEvent event) {
if (event is IncrementEvent) {
_counter++;
} else if (event is DecrementEvent) {
_counter--;
}
_inCounter.add(_counter);
}
void dispose() {
_counterStateController.close();
_counterEventController.close();
}
}Example code:
class CounterScreen extends StatelessWidget {
final CounterBloc _counterBloc = CounterBloc();
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Counter App')),
body: Center(
child: StreamBuilder<int>(
stream: _counterBloc.counter,
builder: (context, snapshot) {
return Text(
'${snapshot.data}',
style: TextStyle(fontSize: 24),
);
},
),
),
floatingActionButton: Column(
mainAxisAlignment: MainAxisAlignment.end,
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
FloatingActionButton(
onPressed: () => _counterBloc.counterEventSink.add(IncrementEvent()),
child: Icon(Icons.add),
),
SizedBox(height: 10),
FloatingActionButton(
onPressed: () => _counterBloc.counterEventSink.add(DecrementEvent()),
child: Icon(Icons.remove),
),
],
),
);
}
}Example code:
@override
void dispose() {
_counterBloc.dispose();
super.dispose();
}
The Flutter Bloc pattern is a powerful tool for managing state in Flutter applications. By separating business logic from UI, it promotes code organization, testability, and scalability. Although it might introduce some initial overhead, especially for simple applications, its benefits become apparent as the project grows in complexity. With the example provided, you can start integrating the Bloc pattern into your Flutter projects and experience its advantages firsthand.
Register Now for the Masterclass to Epic Integration with SMART on FHIR Webinar on Thursday, 10th April 2025 at: 11:00 AM EDT
Register Now
Mindbowser played a crucial role in helping us bring everything together into a unified, cohesive product. Their commitment to industry-standard coding practices made an enormous difference, allowing developers to seamlessly transition in and out of the project without any confusion....
CEO, MarketsAI
I'm thrilled to be partnering with Mindbowser on our journey with TravelRite. The collaboration has been exceptional, and I’m truly grateful for the dedication and expertise the team has brought to the development process. Their commitment to our mission is...
Founder & CEO, TravelRite
The Mindbowser team's professionalism consistently impressed me. Their commitment to quality shone through in every aspect of the project. They truly went the extra mile, ensuring they understood our needs perfectly and were always willing to invest the time to...
CTO, New Day Therapeutics
I collaborated with Mindbowser for several years on a complex SaaS platform project. They took over a partially completed project and successfully transformed it into a fully functional and robust platform. Throughout the entire process, the quality of their work...
President, E.B. Carlson
Mindbowser and team are professional, talented and very responsive. They got us through a challenging situation with our IOT product successfully. They will be our go to dev team going forward.
Founder, Cascada
Amazing team to work with. Very responsive and very skilled in both front and backend engineering. Looking forward to our next project together.
Co-Founder, Emerge
The team is great to work with. Very professional, on task, and efficient.
Founder, PeriopMD
I can not express enough how pleased we are with the whole team. From the first call and meeting, they took our vision and ran with it. Communication was easy and everyone was flexible to our schedule. I’m excited to...
Founder, Seeke
Mindbowser has truly been foundational in my journey from concept to design and onto that final launch phase.
CEO, KickSnap
We had very close go live timeline and Mindbowser team got us live a month before.
CEO, BuyNow WorldWide
If you want a team of great developers, I recommend them for the next project.
Founder, Teach Reach
Mindbowser built both iOS and Android apps for Mindworks, that have stood the test of time. 5 years later they still function quite beautifully. Their team always met their objectives and I'm very happy with the end result. Thank you!
Founder, Mindworks
Mindbowser has delivered a much better quality product than our previous tech vendors. Our product is stable and passed Well Architected Framework Review from AWS.
CEO, PurpleAnt
I am happy to share that we got USD 10k in cloud credits courtesy of our friends at Mindbowser. Thank you Pravin and Ayush, this means a lot to us.
CTO, Shortlist
Mindbowser is one of the reasons that our app is successful. These guys have been a great team.
Founder & CEO, MangoMirror
Kudos for all your hard work and diligence on the Telehealth platform project. You made it possible.
CEO, ThriveHealth
Mindbowser helped us build an awesome iOS app to bring balance to people’s lives.
CEO, SMILINGMIND
They were a very responsive team! Extremely easy to communicate and work with!
Founder & CEO, TotTech
We’ve had very little-to-no hiccups at all—it’s been a really pleasurable experience.
Co-Founder, TEAM8s
Mindbowser was very helpful with explaining the development process and started quickly on the project.
Executive Director of Product Development, Innovation Lab
The greatest benefit we got from Mindbowser is the expertise. Their team has developed apps in all different industries with all types of social proofs.
Co-Founder, Vesica
Mindbowser is professional, efficient and thorough.
Consultant, XPRIZE
Very committed, they create beautiful apps and are very benevolent. They have brilliant Ideas.
Founder, S.T.A.R.S of Wellness
Mindbowser was great; they listened to us a lot and helped us hone in on the actual idea of the app. They had put together fantastic wireframes for us.
Co-Founder, Flat Earth
Ayush was responsive and paired me with the best team member possible, to complete my complex vision and project. Could not be happier.
Founder, Child Life On Call
The team from Mindbowser stayed on task, asked the right questions, and completed the required tasks in a timely fashion! Strong work team!
CEO, SDOH2Health LLC
Mindbowser was easy to work with and hit the ground running, immediately feeling like part of our team.
CEO, Stealth Startup
Mindbowser was an excellent partner in developing my fitness app. They were patient, attentive, & understood my business needs. The end product exceeded my expectations. Thrilled to share it globally.
Owner, Phalanx
Mindbowser's expertise in tech, process & mobile development made them our choice for our app. The team was dedicated to the process & delivered high-quality features on time. They also gave valuable industry advice. Highly recommend them for app development...
Co-Founder, Fox&Fork
