asp.net conditionally disable a tag helper (textarea)

razor asp.net-core-mvc tag-helpers
VMh picture VMh · Jan 19, 2016 · Viewed 15.4k times · Source

I want to enable or disable a textarea depending on a condition that evalueates from the model, and I am using the textarea tag helper. In other words, something like this:

<textarea asp-for="Doc" @(Model.MustDisable ? "disabled" : "")></textarea>

But I got the following design-time error: The tag helper 'textarea' must not have C# in element's attribute declaration area.

Then I tried:

<textarea asp-for="Doc" disabled='@(Model.MustDisable ? "disabled" : "")'></textarea>

which did not show any design time error but it renders like this: Model.MustDisable==true renders disabled='disabled' AND Model.MustDisable==false renders disabled. So the text area will always be disabled.

Then I tried (removing the 's):

textarea asp-for="Doc" disabled=@(Model.MustDisable ? "disabled" : "")></textarea>

which did not show any design time error but it renders the same as the previous one.

How can I implement this the right way?

Answer

GauravD picture GauravD · Jul 14, 2016

I was facing the same issue with select tag helper, i tried few things and it worked. Try this-

<textarea asp-for="Doc" disabled="@(Model.MustDisable ? "disabled" : null)"></textarea>

Related questions

Nesting TagHelpers in ASP.NET Core MVC

The ASP.NET Core TagHelper documentation gives the following example: public class WebsiteContext { public Version Version { get; set; } public int CopyrightYear { get; set; } public bool Approved { get; set; } public int TagsToShow { get; set; } } [TargetElement("website-information")] public class WebsiteInformationTagHelper : TagHelper { public …

Read More
When to use @await Html.PartialAsync in a View in MVC 6

I noticed on one of Scott Hanselman's blogs he uses the following code in his Views when using .Net 5 (MVC 6): @await Html.PartialAsync("_LoginPartial") vs. @Html.Partial("_LoginPartial") Is there any documentation yet on when which one should be used?

Read More
Replacement for @helper in ASP.NET Core

So far, i don't think ViewComponent solves that neither does TagHelper. Is there any replacement to this? Something that takes parameters and returns a HtmlString? I don't see anything harmful with: @helper foo(string something) { <div>Say @something&…

Read More