Introduction to Fluxor: Modern State Management for Blazor Applications

State management is one of the most challenging aspects of modern application development, especially when coordinating several interconnected components. Fluxor is a state management library inspired by the popular Redux library (Created by Meta), designed specifically for Blazor applications. It simplifies state management by centralizing data and ensuring the predictable behavior of your application.

What is Fluxor?

Fluxor is based on the Flux pattern introduced by Facebook. Its primary goal is to provide a unidirectional data flow that eliminates unpredictable behaviors often caused by asynchronous updates or unsynchronized local states.

By using Fluxor, you centralize the state of your application in a store, and updates occur through a well-defined process:

· Action: Represents an intention to modify the state.

· Reducer: A pure function that determines how the state changes in response to an action.

· Effect (optional): Handles asynchronous tasks (e.g., API calls) and triggers new actions in response.

· Middleware (optional): Intercepts actions to perform additional tasks like logging or integration with tools like Redux DevTools.

Source: https://plbonneville.com/blog/build-a-blazor-webassembly-application-using-a-rich-text-editor-in-a-flux-redux-architecture/

Why Use Fluxor?

Fluxor is particularly useful when:

1. Your application's components are highly interconnected.
2. You need to share and synchronize data across multiple parts of your interface.
3. You want to simplify maintaining a complex application.

Advantages and Disadvantages

Advantages

• Centralized State Management: One source of truth for the application state.
• Predictability: Behavior is determined solely by actions and reducers, ensuring a clear data flow.
• Reusability: Actions, reducers, and states are modular and can be reused across projects.
• Debugging Tools: Integrates with Redux DevTools for tracing actions and state transitions.
• Testability: Reducer use pure function that will ease the testability of the application.

Disadvantages

• Initial Complexity: There’s a learning curve to understanding the Flux pattern and implementing it with Fluxor.
• Verbosity: Setting up actions, reducers, and effects can feel cumbersome for small applications.

Implementing the Flux Pattern with Fluxor

To demonstrate Fluxor in action, let’s consider a role-playing game (RPG) application. Players can attack monsters or roll dice, and every action updates a shared global state.

Step 1: Configure Fluxor in Blazor

Add Fluxor to your application in the Program.cs file:

builder.Services.AddFluxor(options =>
{
    options.ScanAssemblies(typeof(Program).Assembly);
    options.UseReduxDevTools();
});        

Step 2: Define the State

States contain the data relevant to your application:

public record CharacterState(int Strength = 10);
public record MonsterState(int Health = 100);        

Step 3: Define Actions

Actions describe the intention to modify the state:

public static class Action
{
    public record RollDiceAction(int RollResult);
    public record MonsterAttackAction(int Damage);
}        

Step 4: Implement Reducers

Reducers determine how the state changes in response to actions:

public static class Reducers
{
    [ReducerMethod]
    public static CharacterState ReduceRollDice(CharacterState state, RollDiceAction action) =>
        state with { Strength = state.Strength + action.RollResult };
 
    [ReducerMethod]
    public static MonsterState ReduceMonsterAttack(MonsterState state, MonsterAttackAction action) =>
        state with { Health = state.Health - action.Damage };
}        

Step 5: Manage Effects

Effects handle asynchronous tasks like API calls:

public class Effects
{
    [EffectMethod]
    public Task LogAction(RollDiceAction action, IDispatcher dispatcher)
    {
        Console.WriteLine($"Dice rolled: {action.RollResult}");
        return Task.CompletedTask;
    }
}        

Step 6: Use Fluxor in a Component

Here’s a Blazor component for rolling a die and updating the state:

@page "/roll-dice"
@using Fluxor
@inject IDispatcher Dispatcher
@inject IState<CharacterState> CharacterState
 
<h3>Roll a Die</h3>
<p>Strength: @CharacterState.Value.Strength</p>
<button @onclick="RollDice">Roll</button>
 
@code {
    private void RollDice()
    {
        int result = new Random().Next(1, 20);
        Dispatcher.Dispatch(new RollDiceAction(result));
    }
}        

Conclusion

Fluxor is an excellent choice for structuring Blazor applications that require robust state management. Although its initial setup can seem daunting, its advantages—centralized state, predictability, and debugging tools—make it ideal for medium to large-scale projects.

If your application involves interdependent components or needs consistent state across its features, Fluxor is well worth considering.

A step Forward

f you want continue your travel inside the world of Fluxor You can check the video of Nick Chapsas :

And for have more key to understand the pattern Flux/Redux you can watch the video of Meta dev :

Have you used Fluxor before? Share your experience in the comments below! ??

Kevin KIEFER, .NET Consultant

Cédric ZULIANI .NET Consultant

Michel VAN HEES .NET Consultant