Require validation only if the field is visible

问题

I am using the [Required] attribute for the client-side validation in ASP.NET MVC 3.

The class looks as:

public class User
{
    [Required(ErrorMessage = "First Name is required")]
    public string FirstName { get; set; }
}

I want the field FirstName to be validated only if it's visible, which will be shown only on certain conditions. How can I do that?

I have used the following, but still it looks to validate for the required field of that hidden field.

$('#registerForm').validate({ ignore: ":not(:visible)" });

回答1:

With some useful hints from @Josiah, i am able to get to my requirement.

Add the RequiredIfAttribute class and the required javascript. Refer Conditional Validation in ASP.NET MVC 3

And in the class add the RequiredIf attribute as:

public class User
{
[RequiredIf("hFirstName", "true", ErrorMessage = "First Name is required")]
public string FirstName { get; set; }

and in aspx:

@Html.TextBoxFor(model => Model.FirstName, new { @style = "height:auto;" })
@Html.ValidationMessageFor(model => Model.FirstName)
@Html.Hidden("hFirstName")

Set the value of hFirstName to 'true' if the FirstName field is hidden and 'false', if visible.

The magic works with these changes. Thanks to @Josiah Ruddell for his answer

回答2:

I would create a conditionally required attribute. There is a good article on creating one with jQuery validation here.

Another option: you could reference a project like Foolproof validation (codeplex) that provides this functionality and the client scripts.

Additionally you could utilize ajax to load your partial views so that they are never on the page when hidden. This would avoid conditional validation altogether.

回答3:

Try my custom validation attribute:

[ConditionalRequired("hFirstName==true")]
public string FirstName {get, set};

It supports multiple conditions.

回答4:

A bit late,

namespace System.ComponentModel.DataAnnotations
{
    public class RequiredIfVisibleAttribute : RequiredAttribute
    {
        protected override ValidationResult IsValid(object value, ValidationContext context)
        {
            if (HttpContext.Current.Request.Form.AllKeys.Contains(context.MemberName))
                return base.IsValid(value, context);

            return ValidationResult.Success;
        }
    }
}

But here's my solution.

Just an inheritance of Required that will act the same way, except that it will only activate if the field if included in the posted keys.

来源：https://stackoverflow.com/questions/5731788/require-validation-only-if-the-field-is-visible