razor - asp.net conditionally disable a tag helper (textarea)

Question

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?

question from:https://stackoverflow.com/questions/34866539/asp-net-conditionally-disable-a-tag-helper-textarea

Answer 1

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>