canvasManagement/Management.Web/Shared/Components/AssignmentForm/RubricEditor.razor

@using Management.Web.Shared.Components

@inject CoursePlanner planner
@inject AssignmentEditorContext assignmentContext

@code
{
  private IEnumerable<RubricItem> rubric { get; set; } = Array.Empty<RubricItem>();
  private int rubricReloadKey = 0;

  protected override void OnInitialized()
  {
    assignmentContext.StateHasChanged += reload;
    reload();
  }
  private void reload()
  {
    if (assignmentContext.Assignment != null)
    {
      rubric = assignmentContext.Assignment.Rubric;
    }
    this.InvokeAsync(this.StateHasChanged);
  }
  public void Dispose()
  {
    assignmentContext.StateHasChanged -= reload;
  }

  private void save()
  {
    if (assignmentContext.Assignment != null)
    {
      var newAssignment = assignmentContext.Assignment with
        {
          Rubric = rubric,
        };
      assignmentContext.SaveAssignment(newAssignment);
      StateHasChanged();
    }
  }
  private void addItem()
  {
    if (assignmentContext.Assignment != null)
    {
      rubric = rubric.Append(new RubricItem
      {
        Label = "",
        Points = 0
      });
    }
  }
  private void removeItem()
  {
    if (assignmentContext.Assignment != null)
    {
      rubric = rubric.Take(rubric.Count() - 1);
      save();
    }
  }
  private void editItem(RubricItem newItem, int index)
  {
    if (assignmentContext.Assignment != null)
    {
      rubric = rubric.Select((r, i) => i == index ? newItem : r);
      save();
    }
  }
  private void MoveUp(RubricItem item)
  {
    if (assignmentContext.Assignment != null)
    {
      var rubricList = rubric.ToList();
      var index = rubricList.IndexOf(item);

      if (index > 0)
      {
        var previous = rubricList[index - 1];
        rubricList[index - 1] = item;
        rubricList[index] = previous;
        rubric = rubricList;
        save();
      }
      rubricReloadKey++;
      StateHasChanged();
    }
  }
  private void MoveDown(RubricItem item)
  {
    if (assignmentContext.Assignment != null)
    {
      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;
        rubric = rubricList;
        save();
      }
      rubricReloadKey++;
      StateHasChanged();
    }
  }

  private int requiredPoints => rubric.Where(r => !r.IsExtraCredit).Select(r => r.Points).Sum();
  private int extraCreditPoints => rubric.Where(r => r.IsExtraCredit).Select(r => r.Points).Sum();
}

<br>
<div class="row">

  <div class="col offset-3">
    <h4 class="text-center">Rubric</h4>
  </div>

  <div class=" col-3 text-end my-1">
    <button
      @onclick:preventDefault="true"
      @onclick="addItem"
      type="button"
      class="btn btn-outline-primary"
    >
      + rubric item
    </button>
  </div>
</div>

<ul class="list-group">
@foreach (var (rubricItem, index) in rubric.Select((r, i) => (r, i)))
  {
    <RubricEditorItem
      @key="@($"index-{index}-key-{rubricReloadKey}-extra-credit-{rubricItem.IsExtraCredit}")"
      RubricItem="rubricItem" 
      OnUpdate="(newItem) => editItem(newItem, index)"
      MoveUp="() => MoveUp(rubricItem)"
      MoveDown="() => MoveDown(rubricItem)"
    />
  }
</ul>


<div class="row">
  <div class="col">
    <div>
      Requred Points: @requiredPoints
    </div>
    <div>
      Extra Credit Points @extraCreditPoints
    </div>
  </div>
  <div class="col">
    <div class="text-end my-1">
      <button
        @onclick:preventDefault="true"
        @onclick="removeItem"
        type="button"
        class="btn btn-outline-danger"
      >
        - rubric item
      </button>
      <button
        @onclick:preventDefault="true"
        @onclick="addItem"
        type="button"
        class="btn btn-outline-primary"
      >
        + rubric item
      </button>
    </div>
  </div>
</div>