HTMLHelpers from MVC2 compatibiliy with Razor

Question

Will existing HTMLHelpers work with Razor? If so, does Razor change anything about either the design or usage of HTMLHelpers?

thx

Answer 1

Yes, existing helpers work perfectly fine with Razor. For example:

@Html.ActionLink("foo bar", "foo")

What Razor changes is that now you have the possibility to define inline helpers like this:

@helper FooBar(string foo)
{
    <div>Hello @foo</div>
}

And use like this:

@FooBar("World")

As far as classic HTML helpers are concerned, Razor changes nothing, it's just a view engine so you continue to write your helpers as you've always did:

public static class HtmlExtensions
{
    public static MvcHtmlString FooBar(this HtmlHelper htmlHelper, string value)
    {
        var builder = new TagBuilder("div");
        div.SetInnerText(value);
        return MvcHtmlString.Create(div.ToString());
    }
}

And use in Razor:

@Html.FooBar("some value")

Answer 2

Razor performs HTML Encoding by default.

So if any of your MVC2 HtmlHelpers emit markup, they might not work if they are returning String instead of MvcHtmlString.