ModelState.AddModelError encodes HTML

Question

I am noticing a weird issue when using ModelState.AddModelError to validate input on my forms. The output from Html.ValidationMessage is not the true HTML value but it's encoded value and so the CSS style is not applied to the error message.

Example:

private string errorMessage = "<span class=\"negative\">{0}</span><br class=\"hid\" />";
ModelState.AddModelError("title", String.Format(errorMessage, "Tab title is required"));

The output is shown as:

<span class="field-validation-error">&lt;span class=&quot;negative&quot;&gt;URL is Required&lt;/span&gt;&lt;br class=&quot;hid&quot; /&gt;</span>

This didn't use to be the case with their earlier beta's and I am not sure what approach to take here.

Thanks Nick

Answer 1

There is another way to do it, too, without having to create your own extension.

Say for instance we have the following in one of our controllers:

ModelState.AddModelError("Name", "<b>Please Use a Valid Person Name</b>");

We can then do the following in our view:

@if(Html.ValidationMessageFor(x => x.Name) != null){
    @Html.Raw(Html.ValidationMessageFor(x => x.Name).ToString())
}

The will prevent the error message of '<b>Please Use a Valid Person Name</b>' from being encoded.

Answer 2

Create your own extension method that mimics Html.VallidationMessage...?

I had to do something similar because the built in MVC validation stuff (ModelState, ValidationMessage etc etc) doesn't cater for pages that have more than one form on a page.