How to keep track of a certain ID while switching through different views in ASP.NET Core?

Question

I have a table called "Releases" with the following fields:

And also a table called "Phases":

As you can see, I have a foreign key called ReleaseId in the second table. What I am trying to do is create multiple Phases within a Release.

In order to do that, in the creation of a Phase, I must also include the ReleaseId , and that should be known by the system beforehand.

I will now make a short walk-through and include some code snippets.

The above screenshot shows the Index method of the ReleaseController. Upon clicking on a Release Name , it will switch the view to show the phases included in that certain release.

PhaseController.cs

public ActionResult Index(int id)
    {
        List<Phase> phaseList = new List<Phase>();

        string connectionString = Configuration["ConnectionStrings:DefaultConnection"];
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string sql = "ReadPhases";
            SqlCommand command = new SqlCommand(sql, connection);
            command.CommandType = CommandType.StoredProcedure;

            SqlParameter parameter = new SqlParameter
            {
                ParameterName = "@ReleaseId",
                Value = id,
                SqlDbType = SqlDbType.VarChar,
                Size = 50
            };

            command.Parameters.Add(parameter);
            using (SqlDataReader dataReader = command.ExecuteReader())
            {
                while (dataReader.Read())
                {
                    Phase phase = new Phase();
                    phase.Id = Convert.ToInt32(dataReader["Id"]);
                    phase.Name = Convert.ToString(dataReader["Name"]);
                    phase.ReleaseId = Convert.ToInt32(dataReader["ReleaseId"]);
                    phaseList.Add(phase);
                }
            }

            connection.Close();
        }
        return View(phaseList);
    }

When you click a Release Name , the method above gets called properly with the help of <a class="btn btn-secondary" asp-area="" asp-controller="Phase" asp-action="Index" asp-route-id="@p.Id"> as in this way I am able to pass the ReleaseId to the Index method. Everything is alright so far as I was able to pass the ReleaseId that I needed.

The problem now is when I want to create a new Phase. I don't know how to get the ReleaseId anymore at this point because I lost the Release model and I can't import multiple models in a view.

   public IActionResult Create()
{
    return View();
}

[HttpPost]
public IActionResult Create(Phase phase)
{
    string connectionString = Configuration["ConnectionStrings:DefaultConnection"];
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        string sql = "CreatePhase";

        using (SqlCommand command = new SqlCommand(sql, connection))
        {
            command.CommandType = CommandType.StoredProcedure;

            // adding parameters
            SqlParameter parameter = new SqlParameter
            {
                ParameterName = "@Name",
                Value = phase.Name,
                SqlDbType = SqlDbType.VarChar,
                Size = 50
            };
            command.Parameters.Add(parameter);

            parameter = new SqlParameter
            {
                ParameterName = "@ReleaseId",
                Value = phase.ReleaseId,
                SqlDbType = SqlDbType.Int
            };
            command.Parameters.Add(parameter);

            connection.Open();
            command.ExecuteNonQuery();
            connection.Close();
        }
    }

    return RedirectToAction("Index");
}

Above is the Create() method. Of course, at this point, it does not work because ReleaseId is an empty field, as I couldn't figure out how to pass it all the way to this view.

Therefore , how can I pass the initial ReleaseId that I first passed when I redirected to the Index method in PhaseController all the way to the Create method?

Hopefully, this is enough information to understand my problem. I opted to exclude the .cshtml code snippets as there was not much going on there. Please let me know if I have to put some more code in the original post.

EDIT:

Index.cshtml (Phase)

@model IEnumerable<Phase>

<h1 class="bg-info text-white">All Phases
    <input type="button"
       onclick="location.href='@Url.Action("Create", "Phase", phase.ReleaseId)'"
       value="Create Phase" /></h1>

<table class="table table-sm table-bordered">
    <tr><th>Name</th><th>Change Name</th><th>Delete</th></tr>
    @foreach (var phase in Model)
    {
        <tr>
            <td>@phase.Name</td>
            <td><a class="btn btn-sm btn-primary" asp-action="Update" asp-route-id="@phase.Id">Change Name</a></td>
            <td>
                <form asp-action="Delete" asp-route-id="@phase.Id" method="post">
                    <button type="submit" class="btn btn-sm btn-danger">
                        Delete
                    </button>
                </form>
            </td>
        </tr>
    }
</table>

Answer 1

You should pass your ReleaseId as a parameter in Create Action. There are a lot of ways to pass a parameter, in the simplest method you can use query string like below:

public IActionResult Create(int releaseId)
{
    ViewDat["ReleaseId"] = releaseId;
    return View();
}

Answer 2

you will need to supply releaseId to your PhaseController's Create Action from the view whereever you are displaying Create button:

<input type="button" 
       onclick="location.href='@Url.Action("Create", "Home", new {Model.FirstOrDefault()?.ReleaseId} )'" 
       value="Create Phase"/>

if you don't button, then you can use it with anchor tag as well as shown below:

<a href='@Url.Action("Create", "Home", new {Model.FirstOrDefault()?.ReleaseId}  )'>Create Phase</a>

Since, we are using FirstOrDefault and when there are no phases then releaseId could be null. So, modify your action to take in nullable int as shown below:

public IActionResult Create(int? releaseId)
{
      if (releaseId.HasValue)
      {
          // Logic when releaseId available
      }
      else
      {
          // Logic when releaseId not available
      } 
}

Answer 3

You can use Query String for carrying the indexes. If this index should be secured you can create a hash key and use that key in the Query String instead of the actual index to prevent manual modifications from the url.