Razor - no longer possible to add an HTML attribute using C#

[razzemans]

Since .NET Core 3.x, it is no longer possible to have C# code in razor when an attribute declaration is expected. The following code used to work pre 3.x:

<option value="@someValue" @if(someCondition) { <text>selected</text> }>
    @displayText
</option>

In .NET Core 3.1, I get the following compilation error:

The tag helper 'option' must not have C# in the element's attribute declaration area.

Maybe it wasn't the most elegant code, but at least it was simple and worked well. I cannot think of a way to get something similar done in .NET Core 3.1. The only workaround I can think of is adding an if else statement and duplicating the HTML option tag, but that hardly seems like good practice. There are other common use cases where one might want to add a similar html attribute (checked, selected).

Either I am missing something utterly obvious or there should be some easy way to make this possible.

Further technical details

• ASP.NET Core version 3.1
• VS Enterprise 2019 16.4.2

[razzemans]

I just learned that when adding null as a value, the attribute isn't rendered. I will close this.