.net core 2.1 validation state: invalid - .net-core

Question

The following simple .NET Core 2.1 MVC code reports "Validation State: Invalid" when I submit to create. Everything works fine without the Owner property; and it works if Owner property is not required.
The Owner is the current user which is in the context of the server side, and it shouldn't be submitted from a client side, so the Create.cshtml doesn't have a Owner input in the form.
The error:
info: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[1]
Executing action method AnnouncementApp.Controllers.AnnouncementsController.Create (AnnouncementApp) with arguments (AnnouncementApp.Models.Announcement) - Validation state: Invalid
The model:
using System;
using Microsoft.AspNetCore.Mvc;
using System.ComponentModel.DataAnnotations;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using AnnouncementApp.Models.Attributes;
using Microsoft.AspNetCore.Identity;
//using System.Security.Claims;
namespace AnnouncementApp.Models
{
public class Announcement
{
public int ID { get; set; }
[Required]
public string Content { get; set; }
[Display(Name = "Start Date and Time")]
public DateTime StartDate { get; set; }
[StartEndDate("End Date and Time must be after Start Date and Time")]
[Display(Name = "End Date and Time")]
public DateTime EndDate { get; set; }
[Required]
[BindNever]
public IdentityUser Owner { get; set; }
}
}
The controller method:
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("ID,Content,StartDate,EndDate")] Announcement announcement)
{
if (ModelState.IsValid)
{
var user = await _userManager.GetUserAsync(this.User);
announcement.Owner = user;
_context.Add(announcement);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(announcement);
}
The Create.cshtml
#model AnnouncementApp.Models.Announcement
#{
ViewData["Title"] = "Create";
}
<h2>Create</h2>
<h4>Announcement</h4>
<hr />
<div class="row">
<div class="col-md-4">
<form asp-action="Create">
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="Content" class="control-label"></label>
<textarea asp-for="Content" class="form-control"></textarea>
<span asp-validation-for="Content" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="StartDate" class="control-label"></label>
<input asp-for="StartDate" class="form-control" />
<span asp-validation-for="StartDate" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="EndDate" class="control-label"></label>
<input asp-for="EndDate" class="form-control" />
<span asp-validation-for="EndDate" class="text-danger"></span>
</div>
<div class="form-group">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</form>
</div>
</div>
<div>
<a asp-action="Index">Back to List</a>
</div>
#section Scripts {
#{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

Answer 1

For Announcement, it will apply [Required] for both client validation and database table.
As the comments indicates, you could consider split Announcement to Db Model and ViewModel, you could define a new AnnouncementViewModel for client validation.
For another option, you could try configure the [Required] in the fluent api instead of attribute.
Here are the detail steps.
Change Announcement
public class Announcement
{
public int ID { get; set; }
[Required]
public string Content { get; set; }
[Display(Name = "Start Date and Time")]
public DateTime StartDate { get; set; }
public string OwnerId { get; set; }
//[Required]
[BindNever]
[ForeignKey("OwnerId")]
public IdentityUser Owner { get; set; }
}
Fluent api in ApplicationDbContext
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.Entity<Announcement>()
.Property(a => a.OwnerId)
.IsRequired();
}
Controller
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("ID,Content,StartDate")] Announcement announcement)
{
if (ModelState.IsValid)
{
var user = await _userManager.GetUserAsync(User);
announcement.Owner = user;
_context.Add(announcement);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(announcement);
}

Answer 2

I am not 100 % sure, what you define as the issue, but if you want to supress the "Model Invalid" error, since you are always setting the Owner property through the HttpContext, you can use the following before validating the model:
ModelState["Owner"].ValidationState = ModelValidationState.Valid
I think your issue is that you tell the router to never bind "Owner", but you still tells it is required, and therefore the ModelState would potentially invalidate it.
As long as the "Required" annotation is used, I do not think the ModelState will validate without it being set correctly.
Example:
ModelState["Owner"].ValidationState = ModelValidationState.Valid
if (ModelState.IsValid)
{
var user = await _userManager.GetUserAsync(this.User);
announcement.Owner = user;
_context.Add(announcement);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(announcement);