CODEWITHSUNDEEP
asp.net-mvcasp.net-core
globetrotter
globetrotter

Reputation: 1047

ASP.NET Core data annotation - different values between two properties

I have this viewmodel:

public class VM
{
    [Required]
    public int Int1 { get; set; }
    [Required]
    public int Int2 { get; set; }
}

In the view, these two ints are chosen via dropdowns. I would like the unobtrusive validation to fail if the same value is selected from both dropdowns (e.g. assume Int1 and Int2 can take values ranging 1-10 and the user chooses 9 for both, validation should fail). I am looking to achieve this with data annotations instead of writing Javascript in the frontend.

I can't find a built-in validation attribute, I found [Compare(string otherProperty)] but I am essentially looking for the negation of Compare.

Upvotes: 0

Views: 500

Answers (1)

Edward
Edward

Reputation: 29976

You need to implement your own logic.

  1. Remote validation Controller 

    public class NotEqualController : Controller
{
        [AcceptVerbs("Get", "Post")]
        public IActionResult Verify()
        {
        string firstKey = Request.Query.Keys.ElementAt(0);
        string secondKey = Request.Query.Keys.ElementAt(1);
        string first = Request.Query[firstKey];
        string second = Request.Query[secondKey];
        if (string.Equals(first, second))
        {
                return Json(false);
                //return Json(data: $"Values for these two fields should not be same.");
        }
        return Json(data: true);
        }
}

  2. Model Configuration 

    public class Product
{
        public int Id { get; set; }
        [Remote(action: "Verify", controller: "NotEqual", AdditionalFields = nameof(UserImage), ErrorMessage = "Are Same")]
        public string Name { get; set; }
        [Remote(action: "Verify", controller: "NotEqual", AdditionalFields = nameof(Name), ErrorMessage = "Are Same")]
        public string UserImage { get; set; }
}

    Since you may use this logic for many different model and fields, I implement the logic to use the fields from querystring instead of Verify method parameter.

Upvotes: 1

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