Attach Required Attribute to To A Property At Runtime RSS

• • Reply
  tinac99

  Member

  48 Points

  291 Posts

  Attach Required Attribute to To A Property At Runtime

  Aug 03, 2020 10:59 PM|tinac99|LINK

  Hello,

  I have a class which is used in a PartialView.  This class is used in a ViewModel.  There are 2 views which use the partial view.  In view1, some properties are required entries. In view2, these are not required.

  Is there anyway for me to attach a [Required] attribute in the property of the class at runtime before rendering the views?

  I'm using MVC, ASP Core 2.0.

  Thanks!

  tinac99

• • Reply
  bruce (sqlwo...

  All-Star

  58124 Points

  15635 Posts

  Re: Attach Required Attribute to To A Property At Runtime

  Aug 04, 2020 12:06 AM|bruce (sqlwork.com)|LINK

  attributes are compile time attributes, so they can not change at runtime. you count use custom validation attibutues that look at other properties to determine. google if validation. you could have two view models.

  bruce (sqlwork.com)
• • Reply
  YihuiSun

  Contributor

  2690 Points

  771 Posts

  Re: Attach Required Attribute to To A Property At Runtime

  Aug 04, 2020 07:07 AM|YihuiSun|LINK

  Hi tinac99,

  tinac99

  Is there anyway for me to attach a [Required] attribute in the property of the class at runtime before rendering the views?

  As far as I know, this idea is almost impossible to achieve, but I have a solution to achieve your needs. If you are willing to try it, you can refer to this example.

  • You can use the required method to make the element necessary.
  • You need to reference the "jquery.min.js" file.

  Model

  public class Test1ViewModel
  {
     public string Id { get; set; }
     public string name { get; set; }
  }

  Controller

          public IActionResult Test1()
          {
              return View();
          }
          public IActionResult Test2()
          {
              return View();
          }
          [HttpPost]
          public IActionResult Test3(Test1ViewModel test1)
          {
              return View();
          }

  Test1

  <h1>Id is not required</h1>
  @Html.ActionLink("To Test2", "Test2", "Test6")
  @await Html.PartialAsync("PartialTest")

  Test2

  <h1>Id is required</h1>
  @Html.ActionLink("To Test1", "Test1", "Test6")
  @await Html.PartialAsync("PartialTest")
  @section scripts{
      <script>
          $(function () {
              $("#Id").attr("required", "true");
          });
      </script>
  }

  Test3

  <h1>Success</h1>
  @Html.ActionLink("To Test2", "Test2", "Test6")
  @Html.ActionLink("To Test1", "Test1", "Test6")

  PartialTest

  @model WebApplication7.Models.Test1ViewModel
  @using (Html.BeginForm("Test3", "Test6", FormMethod.Post))
  {
      <div class="form-group row">
          @Html.LabelFor(m => m.Id, new { @class = "col-sm-2 col-form-label" })
          <div class="col-sm-10">
              @Html.TextBoxFor(m => m.Id, new { @class = "form-control" })
          </div>
      </div>
      <div class="form-group row">
          @Html.LabelFor(m => m.name, new { @class = "col-sm-2 col-form-label" })
          <div class="col-sm-10">
              @Html.TextBoxFor(m => m.name, new { @class = "form-control" })
          </div>
      </div>
      <button type="submit">submit</button>
  }

  Here is the result.

  

  Best Regards,

  YihuiSun

  .NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.