Why is my Viewmodel that I am returning to my POST method in MVC returning a null ViewModel - asp.net-core

Question

I really thought I understood what I was doing, but here goes. I decided I need more properties in my View so I created a ViewModel called ViewDataset and replaced the original Dataset model in the View. On my HttpGet TestDataset the View Model is populated correctly with data from the Viewmodel:
My original dataset that was working is below:
public class Dataset
{
public int Dataset_ID { get; set; }
public int Category_ID { get; set; }
public string Provider { get; set; }
public string Name { get; set; }
public string Institution { get; set; }
public string Description { get; set; }
public string Location { get; set; }
public bool Domestic { get; set; }
public bool International { get; set; }
public bool Includes_PHI { get; set; }
public bool PHI_Limited { get; set; }
public bool Includes_PIL { get; set; }
public bool PIL_Limited { get; set; }
public bool Citation_Requirements { get; set; }
public string Citation_Comments { get; set; }
public Nullable<System.DateTime> Availability_Beg_DT { get; set; }
public Nullable<System.DateTime> Availability_End_DT { get; set; }
public bool Subscription_Renewal { get; set; }
public Nullable<System.DateTime> Subscription_Renewal_DT { get; set; }
public bool Retention_Expiry { get; set; }
public Nullable<System.DateTime> Retention_Expiry_DT { get; set; }
public bool Data_Destruction { get; set; }
public Nullable<System.DateTime> Data_Destruction_DT { get; set; }
public string Data_Destruction_Instructions { get; set; }
public Nullable<int> Contract_ID { get; set; }
public bool Draft_Status { get; set; }
public bool Admin_Only { get; set; }
public string Dataset_Alias { get; set; }
public bool Loc_Amazon { get; set; }
public bool Loc_IT_Research { get; set; }
public bool Loc_Research_Proj { get; set; }
public bool Loc_Secure_Data { get; set; }
public bool Loc_Mercury { get; set; }
public bool Loc_Research_CC { get; set; }
public bool Loc_Research_VM { get; set; }
public bool Loc_External { get; set; }
public bool Access_Url { get; set; }
public bool Access_Download_App { get; set; }
public bool Access_Lab_Terminal { get; set; }
public bool Access_Email_Req { get; set; }
public bool Access_File_Download { get; set; }
public bool Access_Other { get; set; }
public string Location_Notes { get; set; }
public string Access_Notes { get; set; }
public Nullable<System.DateTime> Date_Added { get; set; }
public Nullable<System.DateTime> Date_Modified { get; set; }
public string Added_By_User { get; set; }
public string Updated_By_User { get; set; }
public bool External_Collaborators
{
get; set;
}
}
Here is my new ViewDataset (viewmodel)
public class ViewDataset
{
public Dataset dataset;
public List<SelectListItem> categories_list;
}
Here is my is a sample of my view ... couple of lines, but the view is populated correctly with data from the ViewDataset model
#model ResearchDataInventoryWeb.Models.ViewDataset
<td>
#Html.TextBoxFor(model => model.dataset.Institution, new { placeholder = "<Institution>", #class = "input-box" })
</td>
<td>
#Html.TextBoxFor(model => model.dataset.Name, new { placeholder = "<Dataset Name>", #class = "input-box" })
</td>
#Html.CheckBoxFor(model => model.dataset.Domestic) <span class="display-checkbox">Domestic</span>
#Html.CheckBoxFor(model => model.dataset.International) <span class="display-checkbox">International</span>
#Html.CheckBoxFor(model => model.dataset.Includes_PHI) <span class="display-checkbox">Includes PHI </span>
#Html.CheckBoxFor(model => model.dataset.Includes_PIL) <span class="display-checkbox">Includes PII </span><br />
#Html.CheckBoxFor(model => model.dataset.External_Collaborators) <span class="display-checkbox">External Collaborators Allowed (Sharable)</span>
#Html.CheckBoxFor(model => model.dataset.Citation_Requirements) <span class="display-checkbox">Citation Requirements</span>
<input type="submit" value="TestPost" />
Here is my HttpPost TestDataset : The model Viewdataset (dataset, categories_list) properties that I am passing back from the view are NULL, am I missing something?
[HttpPost]
public ActionResult TestDataset(ViewDataset viewdataset)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://localhost:4251/");
//HTTP POST
viewdataset.dataset.Category_ID = 2;
viewdataset.dataset.Dataset_ID = 1;
viewdataset.dataset.Location = "Fingers Crossed";
viewdataset.dataset.Institution = "Not Null";
var dataset = viewdataset.dataset;
// var postTask = client.PostAsJsonAsync<Dataset>("api/datasets/1", dataset);
var postTask = client.PostAsJsonAsync("api/datasets/1", dataset);
postTask.Wait();
var result = postTask.Result;
if (result.IsSuccessStatusCode)
{
return RedirectToAction("Index");
}
}
ModelState.AddModelError(string.Empty, "Server Error. Please contact administrator.");
return View(viewdataset);
}
Here if my HttpGet TestDataset in case you need to see it
public async Task<ActionResult> TestDataset()
{
//Hosted web API REST Service base url
string Baseurl = "http://localhost:4251/";
List<Dataset> dataset = new List<Dataset>();
List<Category> categories = new List<Category>();
var parm = "1";
var returned = new Dataset();
var ViewDataset = new ViewDataset();
using (var client = new HttpClient())
{
//Passing service base url
client.BaseAddress = new Uri(Baseurl);
client.DefaultRequestHeaders.Clear();
//Define request data format
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//Sending request to find web api REST service resource GetAllEmployees using HttpClient
HttpResponseMessage Res = await client.GetAsync("api/Datasets/" + parm);
HttpResponseMessage Res2 = await client.GetAsync("api/Categories");
//Checking the response is successful or not which is sent using HttpClient
if (Res.IsSuccessStatusCode)
{
//Storing the response details recieved from web api
var EmpResponse = Res.Content.ReadAsStringAsync().Result;
//Deserializing the response recieved from web api and storing into the Employee list
returned = JsonConvert.DeserializeObject<Dataset>(EmpResponse);
}
if (Res2.IsSuccessStatusCode)
{
//Storing the response details recieved from web api
var CatResp = Res2.Content.ReadAsStringAsync().Result;
//Deserializing the response recieved from web api and storing into the Employee list
categories = JsonConvert.DeserializeObject<List<Category>>(CatResp);
}
// Create the Categories Select List
var categoryList = new List<SelectListItem>();
foreach (Category c in categories)
{
categoryList.Add(new SelectListItem
{
Value = c.Category_ID.ToString(),
Text = c.Description,
Selected = (c.Category_ID == returned.Category_ID ? true : false)
});
}
ViewDataset.dataset = returned;
ViewDataset.categories_list = categoryList;
//returned.External_Collaborators = returned.External_Collaborators == null || false ? false : true;
//returning the employee list to view
return View(ViewDataset);
}
}

Answer 1

Try to change
public class ViewDataset
{
public Dataset dataset;
public List<SelectListItem> categories_list;
}
to
public class ViewDataset
{
public Dataset dataset { get; set; }
public List<SelectListItem> categories_list { get; set; }
}