Apparatus.Blazor.State 2.1.23

Apparatus.Blazor.State

Apparatus.Blazor.State is library which provides centralized state management for Blazor webassembly based implementations.

Getting Started

1. Create Blazor webassembly project by running:

dotnet new blazorwasm -o BlazorWebAssemblyApp

2. Install the standard Nuget package into your ASP.NET Blazor project.

    Package Manager : Install-Package Apparatus.Blazor.State 
    CLI : dotnet add package Apparatus.Blazor.State

3. In Program.cs add below line to register the service:

	builder.Services.AddStateManagement(typeof(Program).Assembly);

4. Under States folder, create CounterState.cs class which shousl represent Counter page/component state, also all states should inherit Apparatus.Blazor.State.Contracts.IState interface.

    public class CounterState : IState
    {
        public int CurrentCount { get; set; }
    }

5. Create IncrementCount.cs action in "Actions" folder - all actions should inherit Apparatus.Blazor.State.Contracts.IAction interface.

    public class IncrementCount : IAction
    {
        public int IncrementBy { get; set; }
    }

6. Inherit BlazorStateComponent in Counter.razor page/component, reference CounterState in the component and implement Action Dispatcher:

	@inherits Apparatus.Blazor.State.BlazorStateComponent

    ....
<p role="status">Current count: @State.CurrentCount</p>
<button class="btn btn-primary" @onclick="IncrementCount">Click me</button>

@code {
    CounterState State => GetState<CounterState>(); 
    [Inject] IActionDispatcher Dispatcher { get; set; }

    private void IncrementCount()
    {
        Dispatcher.Dispatch(new IncrementCount { /*IncrementBy = 2*/ });
    }
}

7. Implement Action Handler - Under "Handlers" folder create IncrementCountHandler.cs

  public class IncrementCountHandler : IActionHandler<IncrementCount>
    {
        private IStore<CounterState> _counterStore;
        public IncrementCountHandler(IStore<CounterState> counterStore)
        {
            _counterStore = counterStore; 
        }
        
        public Task Handle(IncrementCount action)
        {
            var newState = _counterStore.State;
            newState.CurrentCount++;
            /*
             * or use action property for increment value
             * newState.CurrentCount = newState.CurrentCount + action.IncrementBy;
             */
            return _counterStore.SetState(newState); 
        }
    }

In this way you can keep your states separated from logic and components/pages.

Subscribe to Action without creating Handler

Subscribe from Blazor component.

 @code {
   [Inject] IActionSubscriber ActionSubscriber { get; set; }
	ActionSubscriber.Subscribe<MyAction>((action) => { ... });
 }

For more complex use cases please check SampleApp available in the repository.