Change the Store to have a typed Payload explaining what the change has been in StateHasChangedEventArgs when mutating the State of the Store.

[le-nn]

Change the Store to have a typed Payload explaining what the change has been in StateHasChangedEventArgs when mutating the State of the Store.

Changes

TPayload is added to the second argument of Store<TState, TPayload> and MementoStore<TState, TPayload> .
Store<TState>, MementoStore<TState> and FluxStore<TState, TCommand> are unchanged

Usage

Define the payload type.

public enum StateChangedType {
    CountUp,
    Loading,
    CountUpAsync,
    SetCount,
    CountUpWithAmount
}

The Payload type is specified in Store Type params in the following way.

Store<AsyncCounterState, StateChangedType>

If you set Payload as the second argument of Mutate(..., StateChangedType.CountUp), you can have Payload in the StateHasChangedEventArgs.

store.Subscribe(e => {
    Console.WriteLine(e.Command.Payload); // Specified Paylaod
});

Example AsyncCounterStore Overview

public record AsyncCounterState {
    public int Count { get; init; } = 0;

    public bool IsLoading { get; init; } = false;

    public ImmutableArray<int> Histories { get; init; } = ImmutableArray.Create<int>();
}

public enum StateChangedType {
    CountUp,
    Loading,
    CountUpAsync,
    SetCount,
    CountUpWithAmount
}

public class AsyncCounterStore : Store<AsyncCounterState, StateChangedType> {
    public AsyncCounterStore() : base(() => new()) { }

    public void CountUp() {
        Mutate(state => state with {
            Count = state.Count + 1,
            IsLoading = false,
            Histories = state.Histories.Add(state.Count + 1),
        }, StateChangedType.CountUp);
    }

    public async Task CountUpAsync() {
        Mutate(state => state with { IsLoading = true, }, StateChangedType.Loading);
        await Task.Delay(800);
        Mutate(state => state with {
            Count = state.Count + 1,
            IsLoading = false,
            Histories = state.Histories.Add(state.Count + 1),
        }, StateChangedType.CountUp);
    }

    public void CountUpManyTimes(int count) {
        for (var i = 0; i < count; i++) {
            Mutate(state => state with {
                Count = state.Count + 1,
            }, StateChangedType.CountUpAsync);
        }
    }

    public void SetCount(int count) {
        Mutate(state => state with {
            Count = count,
        }, StateChangedType.SetCount);
    }

    public void CountUpWithAmount(int amount) {
        Mutate(state => state with {
            Count = state.Count + amount,
        }, StateChangedType.CountUpWithAmount);
    }
}

Sample Source

https://github.com/le-nn/memento/blob/main/samples/Memento.Sample.Blazor/Stores/AsyncCounterStore.cs

[le-nn]

And add docs.