Neighbourhood.omg.lol/Components/StatusList.razor

@inject IJSRuntime JS
@inject State State

@implements IDisposable

@if (Editable) {
  <EditStatusDialog @ref="Dialog" id="EditStatusModal"></EditStatusDialog>
}

@if(statuses != null) foreach(Status status in statuses) {
  <StatusCard Status="@status" Editable="Editable" Dialog="Dialog"></StatusCard>
}

<LoadingCard id="statusLoading" icon="fa-solid fa-message-smile"></LoadingCard>

@code {
  [Parameter]
  public Func<bool,Task<List<Status>?>> StatusFunc { get; set; }
  [Parameter]
  public bool Editable { get; set; } = false;

  public EditStatusDialog? Dialog { get; set; }

  private List<Status>? statuses;
  private int count { get; set; } = 0;
  private int pageSize { get; } = 50;

  protected override async Task OnInitializedAsync() {
    await base.OnInitializedAsync();
    State.PropertyChanged += StateChanged;
    State.CanRefresh = true;

    if (statuses == null || statuses.Count == 0) await LoadNext();
    await InvokeAsync(StateHasChanged);
    await JS.InvokeVoidAsync("removeElementById", "statusLoading");
  }

  public async Task<bool> PullUp() {
    int countBefore = count;
    await LoadNext();
    return (count != countBefore);
  }

  public async Task LoadNext(bool forceRefresh = false) {
    if (statuses == null) statuses = new List<Status>();
    if (forceRefresh) {
      count = 0;
      statuses.Clear();
    }

    var allStatuses = await StatusFunc(forceRefresh);
    if (allStatuses != null && count < allStatuses.Count) {
      statuses.AddRange(allStatuses.Skip(count).Take(pageSize));
      count = statuses.Count;
    }
    await InvokeAsync(StateHasChanged);
  }

  private async void StateChanged(object? sender, PropertyChangedEventArgs e) {
    if (e.PropertyName == nameof(State.IsRefreshing) && State.IsRefreshing) {
      await LoadNext(true);
      State.IsRefreshing = false;
    }

    if(e.PropertyName == nameof(State.AtBottom) && State.AtBottom) {
      await LoadNext();
    }
  }

  public void Dispose() {
    State.PropertyChanged -= StateChanged;
    State.CanRefresh = false;
  }
}