Create list of entities in asp.net core mvc

Question

I want to create an entity in asp.net core mvc. The entity represents an exercise workout, and it has a child collection of exercise sets:

public class Workout
{
    public DateTime Date { get; set; }        
    public string Name { get; set; }
    public string Description { get; set; }

   public virtual ICollection<Set> Sets { get; set; }
}

public class Set
{
    public int Id { get; set; }
    public int ExerciseId { get; set; }
    public int WorkoutId { get; set; }
    public decimal Weight { get; set; }
    public int Reps { get; set; }

    public virtual Exercise Exercise { get; set;  }
    public virtual Workout Workout { get; set; }
}

The form looks like this:

The "Add Set" button uses JavaScript to add a group of "set" related fields to the form, so there can be any number of "set" related fields.

Here is my existing code for the view containing the form:

    @model Weightlifting.Models.Workout

@{
    ViewData["Title"] = "Add Workout";
}

<h2>Add Workout</h2>

<form asp-action="Create">
    <div class="form-horizontal">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <div class="form-group">
            <label asp-for="Date" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="Date" class="form-control" />
                <span asp-validation-for="Date" class="text-danger" />
            </div>
        </div>
        <div class="form-group">
            <label asp-for="Name" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="Name" class="form-control" />
                <span asp-validation-for="Name" class="text-danger" />
            </div>
        </div>
        <div class="form-group">
            <label asp-for="Description" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="Description" class="form-control" />
                <span asp-validation-for="Description" class="text-danger" />
            </div>
        </div>        
        <div class="form-group">
            <fieldset class="form-add-set">
                <label for="sets" class="col-md-2 control-label">Sets</label>
                <div class="col-md-10">
                    <div class="add-sets">
                        <div class="form-inline add-set">
                            <div class="form-group">
                                <label class="control-label">Exercise</label>
                                <select class="form-control" asp-items="ViewBag.Exercises"></select>                               
                            </div>
                            <div class="form-group">                                                               
                                    <label asp-for="Sets.First().Reps" class="control-label"></label>
                                    <input asp-for="Sets.First().Reps" placeholder="Reps" class="form-control" />
                                    <span asp-validation-for="Sets.First().Reps" class="text-danger" />                               
                            </div>
                            <div class="form-group">
                                <label asp-for="Sets.First().Weight" class="control-label"></label>
                                    <input asp-for="Sets.First().Weight" class="form-control" />
                                    <span asp-validation-for="Sets.First().Weight" class="text-danger" />
                            </div>
                            <div class="form-group">
                                <button class="btn btn-remove-set" data-toggle="tooltip" title="Remove Set"><span class="glyphicon glyphicon-minus"></span></button>
                            </div>
                        </div>                    
                    </div>
                    <button class="btn btn-add-set">Add Set</button>
                </div>
            </fieldset>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Save" class="btn btn-primary" />
            </div>
        </div>
    </div>
</form>

<div>
    <a asp-action="Index"><span class="glyphicon glyphicon-arrow-left"></span> Back</a>
</div>

@section Scripts {
<script type="text/javascript">
    $(document).ready(function () {     
        var wrapper = $('.add-sets');

        $(".btn-add-set").click(function(e) {
            e.preventDefault();
            $('.add-set:first-child').clone(true).appendTo(wrapper);

            $('.add-set .btn-remove-set').show();
        });

        $('.btn-remove-set').click(function (e) {
            e.preventDefault();
            $(this).parents('.add-set').remove();

            removeButton();
        });

        function removeButton() {
            if ($('.add-set').length == 1) {
                $('.add-set .btn-remove-set').hide();
            }
        }
    });
</script>
}

And here is the controller action that the view posts to:

public async Task<IActionResult> Create([Bind("Id,Date,Description,Name")] Workout workout)
{
    // do stuff
}

My question is this: How do I code the form so that the "Sets" post to the Set collection in the workout model?

Answer 1

Remove the [Bind("Id,Date,Description,Name")] from your action method.

public async Task<IActionResult> Create(Workout workout)
{
    // do stuff
}

Then apply indexing on your Set properties like this.

<div class="form-inline add-set">
                                <div class="form-group">
                                    <label class="control-label">Exercise</label>
                                    <select name="Sets[0].ExerciseId" class="form-control"><option value="1">Push Up</option>
    <option value="1">Set Up</option>
    </select>

<div class="add-sets">
    <div class="form-inline add-set">
        <div class="form-group">
            <label class="control-label">Exercise</label>
            <select name="Sets[0].ExerciseId" class="form-control" asp-items="ViewBag.Exercises"></select>
        </div>
        <div class="form-group">
            <label asp-for="Sets.First().Reps" class="control-label"></label>
            <input asp-for="Sets.First().Reps" name="Sets[0].Reps" placeholder="Reps" class="form-control" />
            <span asp-validation-for="Sets.First().Reps" class="text-danger" />
        </div>
        <div class="form-group">
            <label asp-for="Sets.First().Weight" class="control-label"></label>
            <input asp-for="Sets.First().Weight" name="Workout.Sets[0].Weight" class="form-control" />
            <span asp-validation-for="Sets.First().Weight" class="text-danger" />
        </div>
        <div class="form-group">
            <button class="btn btn-remove-set" data-toggle="tooltip" title="Remove Set"><span class="glyphicon glyphicon-minus"></span></button>
        </div>
    </div>
</div>

When you add new row dynamically make sure the indexing number must be sequential, start at 0 and not skip any iteration.