How to add a second css class with a conditional value in razor MVC 4

Question

While Microsoft has created some automagic rendering of html attributes in razor MVC4, it took me quite some time to find out how to render a second css class on an element, based on a conditional razor expression. I would like to share it with you.

Based on a model property @Model.Details, I want to show or hide a list item. If there are details, a div should be shown, otherwise, it should be hidden. Using jQuery, all I need to do is add a class show or hide, respectively. For other purposes, I also want to add another class, "details". So, my mark-up should be:

<div class="details show">[Details]</div> or <div class="details hide">[Details]</div>

Below, I show some failed attempts (resulting mark-up assuming there are no details).

This: <div @(@Model.Details.Count > 0 ? "class=details show" : "class=details hide")>,

will render this: <div class="details" hide="">.

This: <div @(@Model.Details.Count > 0 ? "class=\"details show\"" : "class=\"details hide\"")>.

will render this: <div class=""details" hide&quot;="">.

This: <div @(@Model.Details.Count > 0 ? "class='details show'" : "class='details hide'")>

will render this: <div class="'details" hide&#39;="">.

None of these are correct mark-up.

Answer 1

I believe that there can still be and valid logic on views. But for this kind of things I agree with @BigMike, it is better placed on the model. Having said that the problem can be solved in three ways:

Your answer (assuming this works, I haven't tried this):

<div class="details @(@Model.Details.Count > 0 ? "show" : "hide")">

Second option:

@if (Model.Details.Count > 0) {
    <div class="details show">
}
else {
    <div class="details hide">
}

Third option:

<div class="@("details " + (Model.Details.Count>0 ? "show" : "hide"))">