canvasManagement/Management.Web/Shared/Module/Assignment/RubricEditor.razor

@using Management.Web.Shared.Components

@inject CoursePlanner planner

@code
{
  [Parameter, EditorRequired]
  public IEnumerable<RubricItem> Rubric { get; set; } = default!;

  [Parameter, EditorRequired]
  public Action<IEnumerable<RubricItem>> SetRubric { get; set; } = default!;  

  private void addItem()
  {
    SetRubric(
      Rubric.Append(new RubricItem
      {
        Id=Guid.NewGuid().ToString(),
        Label="",
        Points=0
      })
    );
    StateHasChanged();
  }
  private void editItem(RubricItem newItem)
  {
    var newRubric = Rubric.Select(i => i.Id == newItem.Id ? newItem : i);
    SetRubric(newRubric);
    StateHasChanged();
  }
  private void MoveUp(RubricItem item)
  {
    var rubricList = Rubric.ToList();
    var index = rubricList.IndexOf(item);

    if(index > 0)
    {
      var previous = rubricList[index - 1];
      rubricList[index - 1] = item;
      rubricList[index] = previous;
      SetRubric(rubricList);
    }
  }
  private void MoveDown(RubricItem item)
  {
    var rubricList = Rubric.ToList();
    var index = rubricList.IndexOf(item);

    if(index < rubricList.Count())
    {
      var next = rubricList[index + 1];
      rubricList[index + 1] = item;
      rubricList[index] = next;
      SetRubric(rubricList);
    }
  }
}

<br>
<h5>Rubric</h5>
<ul class="list-group">
  @foreach (var rubricItem in Rubric)
  {
    <RubricEditorItem 
      RubricItem="rubricItem" 
      OnUpdate="editItem"
      MoveUp="() => MoveUp(rubricItem)"
      MoveDown="() => MoveDown(rubricItem)"
    />
  }
</ul>

<div class="text-end my-1">
  <button
    @onclick:preventDefault="true"
    @onclick="addItem"
    type="button"
    class="btn btn-outline-primary"
  >
    + rubric item
  </button>
</div>