ASP .NET MVC 5 Checkbox loop for new created values

Question

I have three entity classes:

namespace App.Data.Models
{
    public class Employee
    {
        [Key]
        public int Id { get; set; } 
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public virtual ICollection<Project> Projects { get; set; }

    }
 
    public class Project
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
    }
     public class EmployeeProject
    {
        [Key]
        public int Id { get; set; }
        [ForeignKey]
        public int EmployeeId { get; set; }
        [ForeignKey]
        public int ProjectId { get; set; }

    public virtual Employee  Employee{ get; set; }
    public virtual Project Project { get; set; }
    }
  
}

And one view model class

namespace App.Data.Models
{
public class EmployeeViewModel
    {
        public Employee Employee { get; set; }
        public List<SelectListItem> Projects { get; set; }
    }
}

Right now I am able to add new employees and new projects. I am using localDB and Entity Framework. This is the link to my code https://github.com/IzaGorska/Project

What I want to do is to have checkbox for each project(need to have in mind that I don't have any hard coded projects - creating new project would mean extra checkbox) in EmployeeCreate view. Also in EmployeeDetails view I want to display only checked projects. How can I do that?

I have db for employees and for project. Db for projects:

namespace App.Data.Services
{
    public interface IProjectData
    { 
        IEnumerable<Project> GetAll();
        Project Get(int id);
        void Add(Project project);
        void Update(Project project);   
    }
public class InMemoryProjectData : IProjectData
    {
        List<Project> projects;
        
        public void Add(Project project)
        {
            projects.Add(project);
            project.Id = projects.Max(e => e.Id) + 1;
        }

        public void Update(Project project)
        {
            var exist = Get(project.Id);
            if (exist != null)
            {
                exist.Name = project.Name;
                exist.Description = project.Description;

            }
        }
        public Project Get(int id)
        {
            return projects.FirstOrDefault(e => e.Id == id);
        }

        public IEnumerable<Project> GetAll()
        {
            return projects.OrderBy(e => e.Name);
        }

    }
public class SQLProjectData : IProjectData
    {
        private readonly AppDbContext db;

        public SQLProjectData(AppDbContext db)
        {
            this.db = db;
        }

        public void Add(Project project)
        {
            db.Projects.Add(project);
            db.SaveChanges();
        }

        public Project Get(int id)
        {
            return db.Projects.FirstOrDefault(p => p.Id == id); 
        }

        public IEnumerable<Project> GetAll()
        {
            return from p in db.Projects
                   orderby p.Name
                   select p;
        }

        public void Update(Project project)
        {
            var entry = db.Entry(project);
            entry.State = EntityState.Modified;
            db.SaveChanges();
        }
    }

}

Answer 1

Controller:

public partial class EmployeeController : Controller
{
private readonly AppDbContext _db;

  public EmployeeController(AppDbContext db)
    {
    _db = db;
}
 private List<SelectListItem> GetProjectListItems()
    {
        return _db.Projects.Select(p=> 
            new SelectListItem {
                         Text = p.Name, 
                          Value = p.Id.ToString()
                               }).ToList();
     }
        
  public IActionResult CreateEmployee()
  {
   var employeeViewModel=new EmployeeViewModel
   {
   Employee=new Employee(),
   Projects=GetProjectListItems()
   }
 return View(employeeViewModel);
 }
}

In the view you can use this code to create list of checkboxes:

@using App.Data.Models
@model EmployeeViewModel

.... @Model.Employee input controls
 
<ul>
        @for (var i = 0; i < Model.Projects.Count; i++)
        {
    <li>       
   <input type="checkbox" asp-for="@Model.Projects[i].Selected"  />
   <label asp-for= "@Model.Projects[i].Selected"> @Model.Projects[i].Name</label>
   <input type="hidden" asp-for="@Model.Projects[i].Value" />
   <input type="hidden" asp-for="@Model.Project[i].Text" />                
    </li>
        }
</ul>