State is the cornerstone of making your app and website dynamic and interactive. Holding the data that is fetched from the backend, whether a button is disabled or what text the user has typed, is all handled by the ‘state’. As apps scale, more screens are added, more data is added and this data is persisting between them, how can this complexity be managed?
This is where state management libraries come in to solve your problems. Whether it be removing boilerplate code, adding consistency or matching your team's philosophies, one of these libraries will serve you well.
This list could not have started without the de facto standard bloc library. Business Logic Component (BLoC) is an architecture pattern introduced by Google itself at Google I/O 2018 with the aim of uncoupling business logic from the presentation User Interface (UI). This works by ensuring widgets are aware of the BLoC state at all times, and when it wants to change state, whether programmatically or through user interaction, an event is fired.
The BLoC listens to this event and handles it with the logic it has been defined with. This then emits the new state, which the widget will know of and update accordingly to that state. The bloc library implements all the classes for you in order to implement this design pattern into your codebase, avoiding the boilerplate code of writing it yourself. By separating the logic from the UI, it makes testing much simpler. A widget that has the logic written into it makes you unable to mock it, as the class builds the logic internally and cannot be injected with a fake test one instead.
With BLoC, you can mock widget tests by mocking the bloc class and knowing the states that should be emitted and what the widget tree should look like from the expected state. You can also do integration tests, mocking the BLoC that makes an API call. The maintainability of your app is easer as It also helps with reusability, if the logic is tied to the widget and you run into the scenario that it can be used in another part of the app with different functionality, you would not be able to do so without lifting the logic higher up in the tree and pass callbacks around which can get messy real quick. Having it in the BLoC class separates it into another layer, making it easier to read and understand. It makes bug fixing faster as issues relating to UI, you know, are in the Widgets, logic in the bloc and state in the events and/or states classes.
Riverpod is built with the goal of offering a safer and more flexible approach to managing state. Unlike other solutions that rely heavily on context, Riverpod removes this constraint entirely, giving you full control over where and how your state is created and accessed.
At its core, Riverpod works through providers, which expose pieces of state or logic to your widgets. When the state of a provider changes, any widget listening to it will rebuild automatically. One of Riverpod’s major strengths is its compile-time safety. Errors such as using a provider before it is initialised are caught early, helping avoid runtime surprises.
It also supports dependency injection out of the box, making testing much simpler by overriding providers with mocks during unit, widget, and integration tests without changing the production code. This separation of concerns improves maintainability. Providers keep logic in dedicated classes or functions, while the UI simply watches the state. As your app grows, the clarity of having all logic managed through providers makes your codebase easier to navigate, reduces coupling, and helps teams maintain a consistent architecture.
GetX is a lightweight yet powerful library; its main appeal lies in its simplicity. GetX allows you to manage state with minimal boilerplate and react to changes instantly through its reactive variables.
Instead of dealing with multiple classes or events, the logic lives neatly inside controllers that expose observable values. When one of these values changes, widgets that depend on it are updated automatically.
Testing becomes more straightforward as controllers can be instantiated and mocked directly without relying on widget context, and dependencies can be injected cleanly thanks to GetX’s built-in dependency management system.
This separation between controllers and UI results in better maintainability as apps grow. You avoid scattering logic across widgets and instead keep behaviour inside dedicated controllers, making it easier to track down issues, refactor features, or reuse components across screens.
GetX’s routing and dependency handling also contribute to keeping the project organised, especially when managing larger navigation flows or shared resources. Additionally, it can be used for dependency injection and routing, which you can learn about in a future blog.
Well, unfortunately, as easy as it would be to say one is the best solution, each one offers its own strengths:
Ultimately, it depends on choosing the right one that follows your preferences and makes maintainability easier as your app scales.
Here at Shape, we opted for our standard approach to use the BLoC library. This is for a few reasons:
While the setup of a BLoC takes a bit of time, the benefits in consistency, testability, and maintainability are worth it. With AI these days, the boilerplate code that used to discourage developers is no longer as much of a barrier, as AI can write that boilerplate for us. Once the foundations are in place, making changes across the app becomes straightforward, and tracking down bugs becomes far more manageable.
We still use Flutter's very own setState and Stateful widgets and the other state management providers throughout applications we build, as there is a time and a place for all of these, and we would not want to build if we were limited to just one.
