Question

I have an extension method for getting a string from resource file in asp.net mvc 3

public static string Resource(this HtmlHelper htmlHelper, string expression, params object[] args)
        {

            string path = ((RazorView)htmlHelper.ViewContext.View).ViewPath;
            var fields =
                (ResourceExpressionFields)
                (new ResourceExpressionBuilder()).ParseExpression(expression, typeof(string), new ExpressionBuilderContext(path));
            return (!string.IsNullOrWhiteSpace(fields.ClassKey))
                       ? string.Format((string)htmlHelper.ViewContext.HttpContext.GetGlobalResourceObject(
                           fields.ClassKey,
                           fields.ResourceKey,
                           CultureInfo.CurrentUICulture), args)
                       : string.Format((string)htmlHelper.ViewContext.HttpContext.GetLocalResourceObject(
                           path,
                           fields.ResourceKey,
                           CultureInfo.CurrentUICulture), args);
        }

Here is how I use this method

@Html.LabelFor(m => m.Login, Html.Resource("LoginBoxLoginField")) 

But I don’t know how to use it in an action of controller

public ActionResult MyAction()
        {
             //how to get string from resource file using my extension method?
        }

For example

 if (!ModelState.IsValid)
    ModelState.AddModelError(string.Empty, string.Empty/* should be resource string */);

Answer 1

You cannot use it in the controller because you do not have an instance of HtmlHelper inside the controller. And to create an HtmlHelper instance you need a ViewContext. And you have a view context only inside a view. If you want to use this in a controller you will have to refactor it so that this helper depends only on the HttpContext and not on an HtmlHelper.