Posted ViewModel return null properties

Question

I am having issues with a view model that constantly return null properties after a post. Below is my code (it could be a syntax issue or two calling a class or property the same name as i saw in other posts but i could not see any such issue in code):

VIEW MODEL:

public class ProductItem
    {
        public int ProductID { get; set; }
        public string Code { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public string LongDescription { get; set; }
        public int SupplierID { get; set; }
        public string Dimensions { get; set; }
        public double Price { get; set; }
        public bool On_Sale { get; set; }
        public double DiscountedPrice { get; set; }
        public string Thumbnail { get; set; }
        public string LargeImage { get; set; }
        public string LargeImage2 { get; set; }
        public string LargeImage3 { get; set; }
        public string CrossRef { get; set; }
        public byte Available { get; set; }
        public double Weight { get; set; }
        public byte Important { get; set; }
        public virtual ICollection ProductCategories { get; set; }

        // this is required on the page to allow products to be marked for deletion
        public bool IsForDelete { get; set; }
    }

    public class ProductListViewModel
    {
        public IEnumerable ProductItems { get; set; }
        public IEnumerable CategoryItems { get; set; }
    }

CONTROLLER:

public ActionResult ProductList()
        {
            var productList = new ProductListViewModel();
            productList.ProductItems = productRepository.GetProductsWithDeleteOption().ToList();
            productList.CategoryItems = categoryRepository.GetCategories().ToList();
            return View(productList);
        }

        [HttpPost]
        public ActionResult ProductList(ProductListViewModel productViewModel, FormCollection formCollection, string submit)
        {            
            if (ModelState.IsValid)
            {
                // Check for submit action
                if (submit == "Change Sort")
                {
                    if (formCollection["Sortby"] == "ProductID")
                    {
                        OrderBy(productViewModel, formCollection, "m.ProductID");
                    }
                    else if (formCollection["Sortby"] == "Code")
                    {
                        OrderBy(productViewModel, formCollection, "m.Code");
                    }
                    else if (formCollection["Sortby"] == "Name")
                    {
                        OrderBy(productViewModel, formCollection, "m.Name");
                    }
                    else if (formCollection["Sortby"] == "Price")
                    {
                        OrderBy(productViewModel, formCollection, "m.Price");
                    }
                }
                else if (submit == "Delete all selected")
                {

                }
                else if (submit == "Update All")
                {

                }
                else if (submit == "Restrict Display")
                {

                }
            }
            return View(productViewModel);
        }

VIEW:

@model Admin.Models.ViewModels.ProductListViewModel

@{
    ViewBag.Title = "View Products";
}

@using (Html.BeginForm())
{
Product List as at @DateTime.Now.ToString("dd/MM/yyyy")

    
        Sort by:
        
            
        
        
             Ascending
             Descending
        
        
            
        
    
    
        Display only : (category)
        @Html.DropDownList("CategoryID", new SelectList(Model.CategoryItems, "CategoryID", "Name"), "All Categories")
        
    
    
        
Total Number of products: @Model.ProductItems.Count()
    



@for (var i = 0; i < Model.ProductItems.ToList().Count; i++)
{
    
}


    
        
            Edit
        
        
            Code
        
        
            Name
        
        
            Price
        
        
            On_Sale
        
        
            DiscountedPrice
        
        
            Weight
        
        
            Delete
        
        
    

        
            @Html.HiddenFor(m => m.ProductItems.ToList()[i].ProductID)            
            @Html.ActionLink(Model.ProductItems.ToList()[i].ProductID.ToString(), "ProductEdit", new { id = Model.ProductItems.ToList()[i].ProductID })
        
        
            @Html.DisplayFor(m => m.ProductItems.ToList()[i].Code)
        
        
            @Html.DisplayFor(m => m.ProductItems.ToList()[i].Name)
        
        
            @Html.EditorFor(m => m.ProductItems.ToList()[i].Price)
        
        
            @Html.CheckBoxFor(m => m.ProductItems.ToList()[i].On_Sale, new { id = "On_Sale_" + Model.ProductItems.ToList()[i].ProductID })
        
        
            @Html.EditorFor(m => m.ProductItems.ToList()[i].DiscountedPrice)
        
        
            @Html.EditorFor(m => m.ProductItems.ToList()[i].Weight)
        
        
            @Html.CheckBoxFor(m => m.ProductItems.ToList()[i].IsForDelete, new { id = Model.ProductItems.ToList()[i].ProductID }) 
        
        
            @Html.ActionLink("Edit", "ProductEdit", new { id = Model.ProductItems.ToList()[i].ProductID }) |
            @Html.ActionLink("Details", "Details", new { id = Model.ProductItems.ToList()[i].ProductID }) |
            @Html.ActionLink("Delete", "Delete", new { id = Model.ProductItems.ToList()[i].ProductID })
        
    

    


    



    @Html.ActionLink("Add a new product", "ProductAdd")


}

In the post action, the productViewModel argument has the ProductItems and CategoryItems properties as null.

Brendan Vogt · Accepted Answer

Yes it will be null on post back. I have a similar table in one of my projects and this is what I would have done given my situation.

You could change your view model to look like this then you don't have to do so many converting to lists in your view:

public class ProductListViewModel
{
     public List ProductItems { get; set; }

     public List CategoryItems { get; set; }
}

Now in you view it could look something like this (this is just part of it, then rest you can just go and add):

@for (int i = 0; i < Model.ProductItems.Count(); i++)
{
     
          
               @Html.DisplayFor(m => m.ProductItems[i].Name)
               @Html.HiddenFor(m => m.ProductItems[i].Name)
          
     
     
          
               @Html.CheckBoxFor(m => m.ProductItems[i].IsForDelete)
          
     
}

Add the code and do some debugging to see how the values are returned on submit

I hope this helps.

Posted ViewModel return null properties

Answers (2)

Related Questions