C# – html.hidden for value not set in asp.net MVC core Razor view

asp.netasp.net-coreasp.net-mvcc

I am working on an asp.net MVc core application. I have a popup with a form element like this:

@using (Html.BeginForm("AddIVR", "ITPVoice", FormMethod.Post, new { role = "form" }))
 {    
       @*@Html.HiddenFor(m =>m.m_newIVR.Account, new { @value= Model.accountID})*@
       @Html.Hidden("m.m_newIVR.Account", Model.accountID)    
 }

I have a viewmodel like this:

public class AccountDetailsViewModel
{
    public IVRS m_newIVR { get; set; }
}

and IVRS model class like this:

 public class IVRS
 {

        [JsonProperty("_id")]
        public string Id { get; set; }

        [JsonProperty("name")]
        public string Name { get; set; }

        [JsonProperty("description")]
        public string Description { get; set; }

        [JsonProperty("account")]
        public string Account { get; set; }

}

I am trying to populate it in my view like this:

@Html.HiddenFor(m =>m.m_newIVR.Account, new { @value= Model.accountID})

but when i see view source, Value is null

I tried using:

 @Html.Hidden("m.m_newIVR.Account", Model.accountID)

and it shows m_newIVR.Account populated.

Then I am posting the form to controller this action

 [HttpPost]       
        public ActionResult AddIVR(AccountDetailsViewModel model)
{
 return RedirectToAction("AccountDetails", "mycontroller")
}

Although I see that AccountId is populated in view ( using viewsource), but in post action method value of model.m_newIVR.Account is null.

HTML output looks like this:

        <div id="edit-ivrs-modal" class="modal fade" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true" style="display: none;">


      <div class="modal-dialog">
<form action="/ITPVoice/AddIVR" method="post" role="form">                        <div class="modal-content">
                            <div class="modal-header">

                                <h4 class="modal-title">Add IVR</h4>
                                <input id="m_newIVR_Account" name="m_newIVR.Account" type="hidden" value="" />
                                <input id="AccountId" name="AccountId" type="hidden" value="56f5e3d77ea022a042665be1" />
                            </div>
                            <div class="modal-body">
</div>
</div>

My Questions are:

Why html.hiddenfor is not setting value of the model variable?
Although html.hidden is setting value, why it is not accessible in post action method ?

Please suggest.

Best Answer

Now I am able to answer your question why does it works for Html.Hidden but not for Html.HiddenFor.

When you Html.HiddenFor with m =>m.m_newIVR.Account then it always try to set value for hidden field value whatever value available in property m.m_newIVR.Account not the value that you specify using @value = Model.AccountId.

If you want to use HiddenFor the set m_newIVR.Account in ViewModel just use following thing.

 @Html.HiddenFor(m =>m.m_newIVR.Account)

Html.Hidden is not strongly type so it not depend on name. You can specify different name and value parameter. In this case It is your responsibility to generate proper name for HiddenField.

My Working Sample

Model

public class AccountDetailsViewModel
{
    public string AccountId { get; set; }
    public IVRS m_newIVR { get; set; }
}

public class IVRS
{

    [JsonProperty("_id")]
    public string Id { get; set; }

    [JsonProperty("name")]
    public string Name { get; set; }

    [JsonProperty("description")]
    public string Description { get; set; }

    [JsonProperty("account")]
    public string Account { get; set; }

}

Controller Action

    [HttpGet]
    public IActionResult Index1()
    {
        AccountDetailsViewModel model = new AccountDetailsViewModel();
        //model.AccountId = "1222222";
        model.m_newIVR = new IVRS();
        model.m_newIVR.Account = "122222";
        return View(model);
    }

    [HttpPost]
    public IActionResult Index1(AccountDetailsViewModel model)
    {
        return View(model);
    }

View (Index1.cshtml)

@model WebApplication2.Controllers.AccountDetailsViewModel

@using (Html.BeginForm())
{
    @Html.HiddenFor(m =>m.m_newIVR.Account)    
    <input type="submit" />
}

// Sample Out

Related Solutions

Asp.net-mvc – How to render an ASP.NET MVC view as a string

Here's what I came up with, and it's working for me. I added the following method(s) to my controller base class. (You can always make these static methods somewhere else that accept a controller as a parameter I suppose)

MVC2 .ascx style

protected string RenderViewToString<T>(string viewPath, T model) {
  ViewData.Model = model;
  using (var writer = new StringWriter()) {
    var view = new WebFormView(ControllerContext, viewPath);
    var vdd = new ViewDataDictionary<T>(model);
    var viewCxt = new ViewContext(ControllerContext, view, vdd,
                                new TempDataDictionary(), writer);
    viewCxt.View.Render(viewCxt, writer);
    return writer.ToString();
  }
}

Razor .cshtml style

public string RenderRazorViewToString(string viewName, object model)
{
  ViewData.Model = model;
  using (var sw = new StringWriter())
  {
    var viewResult = ViewEngines.Engines.FindPartialView(ControllerContext,
                                                             viewName);
    var viewContext = new ViewContext(ControllerContext, viewResult.View,
                                 ViewData, TempData, sw);
    viewResult.View.Render(viewContext, sw);
    viewResult.ViewEngine.ReleaseView(ControllerContext, viewResult.View);
    return sw.GetStringBuilder().ToString();
  }
}

Edit: added Razor code.

Asp.net-mvc – ASP.NET MVC – Set custom IIdentity or IPrincipal

Here's how I do it.

I decided to use IPrincipal instead of IIdentity because it means I don't have to implement both IIdentity and IPrincipal.

Create the interface

interface ICustomPrincipal : IPrincipal
{
    int Id { get; set; }
    string FirstName { get; set; }
    string LastName { get; set; }
}

CustomPrincipal

public class CustomPrincipal : ICustomPrincipal
{
    public IIdentity Identity { get; private set; }
    public bool IsInRole(string role) { return false; }

    public CustomPrincipal(string email)
    {
        this.Identity = new GenericIdentity(email);
    }

    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

CustomPrincipalSerializeModel - for serializing custom information into userdata field in FormsAuthenticationTicket object.

public class CustomPrincipalSerializeModel
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

if (Membership.ValidateUser(viewModel.Email, viewModel.Password))
{
    var user = userRepository.Users.Where(u => u.Email == viewModel.Email).First();

    CustomPrincipalSerializeModel serializeModel = new CustomPrincipalSerializeModel();
    serializeModel.Id = user.Id;
    serializeModel.FirstName = user.FirstName;
    serializeModel.LastName = user.LastName;

    JavaScriptSerializer serializer = new JavaScriptSerializer();

    string userData = serializer.Serialize(serializeModel);

    FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket(
             1,
             viewModel.Email,
             DateTime.Now,
             DateTime.Now.AddMinutes(15),
             false,
             userData);

    string encTicket = FormsAuthentication.Encrypt(authTicket);
    HttpCookie faCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encTicket);
    Response.Cookies.Add(faCookie);

    return RedirectToAction("Index", "Home");
}

Global.asax.cs - Reading cookie and replacing HttpContext.User object, this is done by overriding PostAuthenticateRequest

protected void Application_PostAuthenticateRequest(Object sender, EventArgs e)
{
    HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];

    if (authCookie != null)
    {
        FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);

        JavaScriptSerializer serializer = new JavaScriptSerializer();

        CustomPrincipalSerializeModel serializeModel = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData);

        CustomPrincipal newUser = new CustomPrincipal(authTicket.Name);
        newUser.Id = serializeModel.Id;
        newUser.FirstName = serializeModel.FirstName;
        newUser.LastName = serializeModel.LastName;

        HttpContext.Current.User = newUser;
    }
}

Access in Razor views

@((User as CustomPrincipal).Id)
@((User as CustomPrincipal).FirstName)
@((User as CustomPrincipal).LastName)

and in code:

    (User as CustomPrincipal).Id
    (User as CustomPrincipal).FirstName
    (User as CustomPrincipal).LastName

I think the code is self-explanatory. If it isn't, let me know.

Additionally to make the access even easier you can create a base controller and override the returned User object (HttpContext.User):

public class BaseController : Controller
{
    protected virtual new CustomPrincipal User
    {
        get { return HttpContext.User as CustomPrincipal; }
    }
}

and then, for each controller:

public class AccountController : BaseController
{
    // ...
}

which will allow you to access custom fields in code like this:

User.Id
User.FirstName
User.LastName

But this will not work inside views. For that you would need to create a custom WebViewPage implementation:

public abstract class BaseViewPage : WebViewPage
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

public abstract class BaseViewPage<TModel> : WebViewPage<TModel>
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

Make it a default page type in Views/web.config:

<pages pageBaseType="Your.Namespace.BaseViewPage">
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Routing" />
  </namespaces>
</pages>

and in views, you can access it like this:

@User.FirstName
@User.LastName

Best Answer

Related Solutions

Asp.net-mvc – How to render an ASP.NET MVC view as a string

Asp.net-mvc – ASP.NET MVC – Set custom IIdentity or IPrincipal

Related Topic