Converting ASP.NET MVC Razor @helper function into a method of a helper class

Question

Consider the following ASP.NET MVC razor view snippet which defines a helper

@helper FieldFor(Expression> expr         


        

Answer 1

The signature would need to be

public static MvcHtmlString FieldFor(this HtmlHelper helper, Expression> expression)

Then you use a combination of TagBuilder and the inbuilt html helper methods to generate the html

using System;
using System.Linq.Expressions;
using System.Text;
using System.Web.Mvc;
using System.Web.Mvc.Html;

namespace YourAssembly.Html
{
  public static class FieldHelper
  {
    public static MvcHtmlString FieldFor(this HtmlHelper helper, Expression> expression)
    {
      MvcHtmlString label = LabelExtensions.LabelFor(helper, expression, new { @class = "control-label col-md-2" });
      MvcHtmlString editor = EditorExtensions.EditorFor(helper, expression, new { htmlAttributes = new {@class = "form-control"}})
       MvcHtmlString validation = ValidationExtensions.ValidationMessageFor(helper, expression, null, new { @class = "text-danger" });

       StringBuilder html = new StringBuilder();
       html.Append(editor);
       html.Append(validation);
       TagBuilder innerDiv = new TagBuilder("div");
       innerDiv.AddCssClass("col-md-10");
       innerDiv.InnerHtml = html.ToString();
       html = new StringBuilder();
       html.Append(label);
       html.Append(innerDiv.ToString());
       TagBuilder outerDiv = new TagBuilder("div");
       outerDiv.AddCssClass("form-group");
       outerDiv.InnerHtml = html.ToString();
       return MvcHtmlString.Create(outerDiv.ToString());
    }
  }
}

Then your can make it available in all you views by adding it to web.config

  
    
      
      ....