Question

Is there a utility function for escaping JavaScript in ASP.NET MVC views? I often need to init a little snippet of JavaScript using some values from the view; for instance I may have something like:

<script type="text/javascript">
var page = new Page({ currentUser: "<%= Model.UserName %>" });
page.init();
</script>

I would expect something like:

<script type="text/javascript">
var page = new Page({ currentUser: "<%= Html.JavaScriptEscape(Model.UserName) %>" });
page.init();
</script>

I could, of course, write the function myself. But since there are already built-in utilities form HTML encoding, and since one of the selling points of ASP.NET MVC is that the <% %> is the default rendering mode, and since what I’m trying to achieve is quite common, it makes me wonder why I cannot find anything like that already built-in. Is there, for instance, an easy and elegant way to serialize an object to JSON in views?

Or am doing something against ASP.NET MVC principles? When I hit a problem like this, it usually makes it think that either I’m doing something wrong since I assume that the framework designers spent some time thinking about real world scenarios.

Answer 1

After some time working in ASP.NET MVC, I concluded that (most likely) there is no build-in helper for it. Of course, it’s trivial to write your own. Here is it for the sake of completeness:

using System.Web.Mvc;
using System.Web.Script.Serialization;

namespace MyProject.Helpers
{
    public static class JsonExtensions
    {
        public static string Json(this HtmlHelper html, object obj)
        {
            JavaScriptSerializer jsonSerializer = new JavaScriptSerializer();
            return jsonSerializer.Serialize(obj);
        }
    }
}

In a view, it can be used as follows:

<script type="text/javascript">
var page = new Page(<%= Html.Json(new { currentUser: Model.UserName } ) %>);
page.init();
</script>